Jippe's wetback 10

[Jippe]

My wetback 10 & yamato 302 (+headless driver)
Top speed 59 mph last summer, measured with gps. (no airtraps and poor quality bottom paint)
More pictures (http://www.valimo.info/wetback-10/) and videos on youtube (http://www.youtube.com/user/JippeFIN/)
http://www.valimo.info/wp-content/gallery/wetback-10-2010/web_Kuva001.jpg

[Mark75H]

Keep working, there is more there!

[F-12]

You finally found a way to race without a helmet! Somehow, someone will make a rule to strap it on your butt..............

[DeanFHobart]

Very nice..... install air traps and front deck cowl. The deck cowl in front of the dash board will make the boat look better.... and look finished.

With the air traps you should get over 60 mph for sure.... without any prop change. Then prop work will and raising the motor will get even more. Keep the prop shaft at least 1" below the bottom of the boat for safety. The older designs were not designed for jacking up the motor to the max. Also, the prop shaft should be level with the bottom of the boat to start with. Maybe kicked out just a little.

Really cool..... keep up the good work.

Good Luck.

[Jippe]

Hi,

Is there any alternatives for NGK R8102-10, R8108-10 or R7424A-9?
They are hard to find...

[zul8tr]

go to Rick Montoya site and look under technical, I think there is a link on this site but for sure on hydroracer.net. The 18mm are hard to find so if you have that head you can change it to the 14mm head or use 18mm to 14mm adapters and then use 14mm plugs. There are many of those available. Ric suggests to go 1 heat range colder with the adapters compared to what was in the engine with 18mm plugs.

[Jippe]

I have 14mm head and R7424A-9 spark plugs, they came with engine.
Manual says R8102-10 or R8108-10.

It is very hard start on cold. Spark plugs get wet all the time.. I have to let it idle ~15s. then pull the choke again 2-3s. and idle ~15s. etc. If I touch throttle plugs get wet.

Any ideas?

[Mark75H]

That's not being caused by the spark plugs. Check something else

[Jippe]

Now it works like a champ :) (after three days pulling and cursing, no idea what was wrong)

Today, first time, I drive trough wave and get really wet :D:eek:

[Jippe]

How long airtraps should be? Do I made them full length or less?

I have Dewalds prop, is there way find out proc specs?

[JohnsonM50]

The prop #'s probably tell what it is. The Wetback a pal built that Ive driven quite a bit had a tendency to cut the top off a wave & smack the drivers face wickedly.:eek: His had traps & was nose heavy. By changing the traps to hold more air & end at the transom, eliminating the heavy front hatch cover for a 1/8 ply cowl & moving the gas tank back it got alot better & is faster too.:cool: His is a Clark Craft kit & is pretty heavy at 178 w/ hardware.

[zul8tr]

How long airtraps should be? Do I made them full length or less?

I have Dewalds prop, is there way find out proc specs?

When I was racing my Wetback with a Yamato Y80 and the Merc 25ss back in 1973 to 1980 I had full traps that faded to zero at the rear. The deck design on the Wetback creates a lot of aero lift and it made my Wetback light in the front. I used a gas tank in the rear inside aginst the transom it held about 0,6 gallons. Racing weight of boat was 125 lb with hardware and 355 lb minimum to meet APBA rules for 25ssh class and 380 lbs minimum to meet APBA 20ssh rules. I would be only a few pounds above these minimums at end of heats.

Here is a shot under way in the 25ssh class back in 1978 Region 5, Wetback fabric deck was changed to Okume and cowl modified in 1978. 25ss top speed was about 63mph, Pinner 2 blade @ 7100 rpm engine rpm and 16:21 gears, prop shaft level to bottom (no kick out) and 3/4" depth of shaft. With the Yamato Y80 I had to add a small turn fin at the rear to prevent rear spin out in the turns.

If your Wetback is not too heavy and a correct cowl added, gas tank in rear + full traps with a 302 spinning 7100 rpm (correct prop) you should be in the high 60's. At that speed this boat requires carefull trim and driving so be careful:eek::eek::eek:.

If your boat is heavy (especially front heavy) you will always have difficulty turning it because the right sponson will be in the water and it will have a tendency to cut left. Make sure your turn fin is far enough outboard on the left spenson so that the fin water spray does not hit the rear deck outer edge.

If you want more specific info on the Wetback PM me.

[JohnsonM50]

When I was racing my Wetback with a Yamato Y80 and the Merc 25ss back in 1973 to 1980 I had full traps that faded to zero at the rear. The deck design on the Wetback creates a lot of aero lift and it made my Wetback light in the front. I used a gas tank in the rear inside aginst the transom it held about 0,6 gallons. Racing weight of boat was 125 lb with hardware and 355 lb minimum to meet APBA rules for 25ssh class and 380 lbs minimum to meet APBA 20ssh rules. I would be only a few pounds above these minimums at end of heats.

Here is a shot under way in the 25ssh class back in 1978 Region 5, Wetback fabric deck was changed to Okume and cowl modified in 1978. 25ss top speed was about 63mph, Pinner 2 blade @ 7100 rpm engine rpm and 16:21 gears, prop shaft level to bottom (no kick out) and 3/4" depth of shaft. With the Yamato Y80 I had to add a small turn fin at the rear to prevent rear spin out in the turns.

If your Wetback is not too heavy and a correct cowl added, gas tank in rear + full traps with a 302 spinning 7100 rpm (correct prop) you should be in the high 60's. At that speed this boat requires carefull trim and driving so be careful:eek::eek::eek:.

If your boat is heavy (especially front heavy) you will always have difficulty turning it because the right sponson will be in the water and it will have a tendency to cut left. Make sure your turn fin is far enough outboard on the left spenson so that the fin water spray does not hit the rear deck outer edge.

If you want more specific info on the Wetback PM me.

You may well have had the fastest B Wetback there ever was Pete. :cool: My pals is wild at 50-ish, I agree about being careful.

[zul8tr]

You may well have had the fastest B Wetback there ever was Pete. :cool: My pals is wild at 50-ish, I agree about being careful.

I don't know about the fastest B Wetback cause I only raced in Region 5 but I did very well with High Point champ in 1975. During my time from 73 to 80 the competitors were: Dave Rawson, Bunky Bowerman, Fred Townson, Jeff Hutchions, Chuck Bentz, Marshall Eldridge Jr, Steve DiNickelantonio and others. Jeff was running a Craig Craft with US 1 and I managed to get ahead of him on several occasions.

The Wetback was very stable once I worked out the bugs and got it properly balanced for the 60 + speeds and turning. When I modded the deck and cowl in 1978 it was a better balanced boat and more predictable. Thanks to Harry Pinner for the props.:D

I miss those days with 35+ 25ss hydros in eliminations.
The Yamato Y80 was a real blast on the Wetback a total relearn curve compared to the Merc 25SS.:eek:

[Jippe]

Thank you for the feedback!
For now max rpm is 6000-6100, measured with tiny tach.
I have to draw air traps soon for the subcontractor, so I go with full lenght and fading to zero.
I have also nose cone for yamato stock gear case.
Boat bottom paint surface is like orange peel, plan is sand and repaint it and I make finally cowl :)

How those improvements effect to rpm with same prop?

[Jippe]

Prop pin breaks off and prop gets stuck to axle.. :mad:
How to get prop off from axle?

[Tim Chance]

Prop pin breaks off and prop gets stuck to axle.. :mad:
How to get prop off from axle?

You need to use a gear puller that gets behind the prop so you can pull it off. If you can't get behind the prop you will need to make something to pull from the shear pin holes.

[zul8tr]

If using a puller fails try heating the outside hub of the prop on all sides to enlarge the hole. Do not apply heat too long because it will also heat up the prop shaft (axel) and still result in a stuck prop. Then immediatly after or during heating with a helper be prepared to pull on the prop at the hub next to the big aluminum cone on the lower unit. There has to be some space in there to insert the 90 degree puller arms or as suggested devise a puller using the shear pin holes. It would also help if you use some JB Blaster penetrating oil on the shaft and prop hub interface.

If that fails how much do you love :D this prop? Because you might have to wack :eek::eek: at each blade with the heat applied to the hub. That might do it.

If you get it off clean the shaft with fine wet sand paper and the next prop make sure the fit is slightly loose so that if you shear a pin the prop willl have less chance to weld to the shaft. I place heavy duty disk brake wheel bearing grease with moly additive on the shaft and inside the prop hub to act as a lubricant in case of a sheared pin. This helps for a short time if the engine is shut off as soon as possible.

Get some stronger shear pins.

Let us know how you do. :)

[Mark75H]

Another possibility that should not be overlooked is pushing the prop back on and aligning the holes and driving the pin out with a punch.

Its usually what you should try to do first when a pin breaks, rather than attempting to force the prop off around broken parts of pin galling the inside of the prop.

[zul8tr]

That is definately a good 1st to do but it does require rotating the prop on the shaft to align the pin hole and from what I have seen they can get very jambed. Perhaps the heat for this case will aid in the prop rotation to align the pin hole.

[Mark75H]

A very good suggestion

[Master Oil Racing Team]

I agree. As a novice in my first year of racing I did the same thing, and did not ask for guidance. Didn't know anyone to ask and my Dad was working....no cell phones then. So I hooked the ends of the puller around the tips of the two blades of the propeller. It took some work, but it finally came loose with a sudden spurt.

As happy as I was at first, my reaction did a 180 south when I looked at the indentiones at the tips of the blades. As it turned out, (similar to the saying that God protects babies and drunks), the prop always was the best one on the hydro and runabout for our two cylinder FB Konig. It's highly unlikely that you would get the same result by attaching the puller in any place but where Tim suggested. Some good quality oil in the shear pin hole and light heating up, down, and around the prop hub before you cranked down on the puller should also help.

[Jippe]

Theres no room for puller but the pin is out. It is stuck really tight :eek:

[zul8tr]

Looks like the pin is still in there? Try the advice already posted. Make a puller that uses the pin holes in the prop that you grab from both sides. As noted abpve apply heat to the hub then immediatly pull. If that fails you will probably need to grab the blades close to the hub with a sling type straps attached to the puller.This probably will damage the prop.:eek: but last resort.

[JohnsonM50]

Looks like the pin is still in there? Try the advice already posted. Make a puller that uses the pin holes in the prop that you grab from both sides. As noted abpve apply heat to the hub then immediatly pull. If that fails you will probably need to grab the blades close to the hub with a sling type straps attached to the puller.This probably will damage the prop.:eek: but last resort.
Maybe not, if you get it in close & keep it from wandering out. Since the prop is sharp & likely to cut, dulling it where you want to strap it to pull then re-edging it later will probably not hurt performance. With the pin out its likely jammed where the distorted metal on the shaft bulges & may be hard to move but pop loose suddenly. Hopefully its not pin debris that would gall the whole way out. Good Luck.

[F-12]

You're going to have to drill out the pin on both side and uses these holes to form a puller. Not mush else with the situation in the pics.

[Gene East]

If you have access to a milling machine, special "arms" with short pins can be fashioned for a standard T-bar gear puller.

We always used a small C-clamp to hold the puller arms tight against the prop to minimize the possibility of the pins popping out.

Probably pulled 100 or more 2 blade props with the one we had. Three/four blade will require a bit more refining.

Every boat racer needs a prop puller. Thick leather gloves are a good idea too.

[Master Oil Racing Team]

With the pin hole looking up, drizzle some good penetrating oil....a high temp oil, and put a little heat around the hub. All the way around. Doesn't have to be real hot...just enough to get the heat all the way to the prop shaft. That makes the hub expand and the oil have some room to sneak in underneath. After heating the hub, drizzle more oil in, then let it soak overvnight. The next day or so take a light sledge hammer, or a regular hammer with some weight, and with back up on the unit , shaft speficically, so it doesn't give...use a punch to get the shear pin out of there. You can't do any good trying to get that prop off with such a metal mass 180 degrees opposing you. As Charley says, you may have to drill the pin from each end, but since you welding it to the shaft with the shear pin still visible, I think some heat, with good oil and the procedure above, you should be able to remove the pin and get the prop off without any further damage. Tim's method will only work if you have the shear pin holes to fit the tool in. The Straps could work too, but only if the shear pin is gone. The only times we ever sheared pins that got welded (besides too much power with the bigger motors) was when we overtighted, and started the shear in the first place. Never hit anything to cause it to shear.

[FurnalFlyer]

We had a few of these over the years we were racing. Had prop pullers made at Kodak that worked well. When went to 3 blades couldn't use prop pullers anymore. The way we got them off was to get an impact chisel like you would cut fenders off of cars, We would take the cutting tool and cut the cutting end of the tool off so that it was blunt. Make sure that it is a little smaller in diameter then the prop shaft Put the prop nut on the end of the prop shaft, leave it up just a little bit so the tool goes inside the nut to hit the prop shaft. We used rags around the blades and let the lower unit hang between two pieces of wood on the rags. Have someone hold the lower unit, so the lower unit is hanging down, and with small bursts of the impact it will drive the shaft right out. Need pressure on the impact gun while doing this, it never failed for us.

Leigh

[Jippe]

Many thanks for your help!

[zul8tr]

What was the final process that worked to pull the prop?
Remove those high spots then polish with some very fine emory cloth and oil.

[Jippe]

5mm bolts on pin holes holding small two clamps puller. Heat to prop and cold spray to shaft. It moved 1-2 mm on one heating/colding...

Do you use something (vaseline, oil..) between shaft and prop to make remove easier?

[Mark75H]

Do you use something (vaseline, oil..) between shaft and prop to make remove easier?

No, it should not be a press fit and should come off easily when the prop nut is removed.

[zul8tr]

I always applied hi temp disk brake wheel bearing grease with moly (Molybdenum disulfide ) additive on the shaft and in the prop bore to provide a bit of tuff lube incase there was a pin shear :eek:. Prop may still stick but may not, any case there was grease on the shaft to aid in removal if stuck somewhat. On the 25ss prop shaft cone needle bearings I also greased them with the same grease, really helped the life of these needles and the prop shaft finish. Lucky, but never did shear a pin. :)

[Jippe]

Nose cone is now welded. What epoxy I should use to fillings?
I also got full lenght air traps (3mm aluminum), I post pictures later..

I have tree blade dewalds cleaver (dewalds P-779, qualifierosy 400), diameter is 178-180mm and I havve no idea what the pitch is. Motor quite high, shaft was about 15 above bottom I got max 6100-6200 rpm, weather/water was perfect for speed testing..

I bought 4 2 blade props with 15mm shaft hole and my shaft is 16mm :D


Increasing yamato power:
I want to keep intertal exhaust, externals are not possibly for lakes.
Polishing channels?, cc'ing power head for more compressions?, timing adjust?, bigger carb?, power reeds? Is there any other tricks? I dont race, so no rules ;)

[zul8tr]

What do you mean 15 above the bottom? With that height and only getting 6100 - 6200 revs I think the prop has way to much pitch or your engine not producing. The 180 mm diameter is about 7.1" that seems in range but I have heard of in the 6.75" range being used.

I would use JB weld Marine (not their 4 minute mix). You will need to rough up the aluminum and clean well with acetone or laquer thinner. They sell it in the larger containers rather than the small tubes. Do you have a pattern for the final shape to transisition to the skeg? I would have used a bullet shaped extension that better fits the existing nose cone. I have seen them and they are cast with a cup that better fits the profile of the existing foot nose, less filler needed. Performance differences?

I think the hatchet wedge needs to be contoured to a curve.

[Jippe]

Sorry, I mix the words. I meant center of shaft is 15mm below the bottom :)
180mm is not exact, it's measured blade tip to center and doubled.

[JohnsonM50]

I think the contouring of the hatched roughly would be good to do 1st as part of prepping for epoxy. Ive used JB Weld & PC7 with good results in similar water stress situations. As long as its roughed well for the epoxy to grab in & very clean it should hold up. Ive made a straight edge connected to a V block to clamp to a prop shaft. The straight edge reaches forward along the side about an inch or 2 away & can be used to check for profile centering.
Good Luck

[Jippe]

Thanks, I order that (JB marine weld).

Any comments on yamato power mods?

[Jippe]

I try to disassemble prop shaft. How to remove ring with text: IKO JAPAN TR 223425 ??
Instructions says that it's next part to remove...
Prop shaft is going to machinist who reduce it to 15mm.
If I want use 16mm prop, what is best material to make spacer/bushing? It has to be only 0,5mm wall.

[Techteam]

I try to disassemble prop shaft. How to remove ring with text: IKO JAPAN TR 223425 ??
Instructions says that it's next part to remove...
Prop shaft is going to machinist who reduce it to 15mm.
If I want use 16mm prop, what is best material to make spacer/bushing? It has to be only 0,5mm wall.

I think that's a needle roller bearing, if you remove the woodruff key from the shaft it should slide off ?

[Master Oil Racing Team]

I originally thought it was a woodruff key too, but things don't look right. There seems to be no slot in the inner race, or sleeve or whatever that is, and see how eccentric it is over the shaft? Perhaps it's some type of wedge. If so you could set the bearing on something that would allow the shaft to pass through and press or whack the shaft from the other side. A picture of the back side might make it more clear how to remove the shaft.

The way it's set up now seems to me would create a vibration.

[Techteam]

I originally thought it was a woodruff key too, but things don't look right. There seems to be no slot in the inner race, or sleeve or whatever that is, and see how eccentric it is over the shaft? Perhaps it's some type of wedge. If so you could set the bearing on something that would allow the shaft to pass through and press or whack the shaft from the other side. A picture of the back side might make it more clear how to remove the shaft.

The way it's set up now seems to me would create a vibration.

I think the photo is throwing you, the shaft is the inner race and because the woodruff key is set back from the end of the shaft and half moon shaped you cannot see the recess.

[Master Oil Racing Team]

You're right, the photo is throwing me. Everything is concentric except the shaft as it appears in the photo. It looks like the shaft is touching the black ring at the 2:00 position and has the widest gap at 8:00., and so I don't get it how the shaft could serve as an inner race. It might be an optical illusion,or something else in the photo throwing me off, but it doesn't look right.

[Jippe]

Hi,

Here is few more pictures.. Need help for deassembly

E: Pictures added

[F-12]

I think the angle of the photo is throwing everyone off. The shaft has (bearing) a slide fit through the race and the key is just a bit off center at this angle. Pretty straightforward after you look closely.

[Jippe]

New photos more angled.

[Jippe]

Cylinder head goes today to machinist, so I need quick answer, please :)
Theres 2mm gap/space between head and piston, is ok to reduce it to 1,2mm? (cc'ing 0.8mm off.)
I measured both cylinders compression pressures and they are both 100 psi with cold engine.

Prop end of shaft is stil on it's place, how to remove it? No help for heating like another end.
http://www.boatracingfacts.com/forums/attachment.php?attachmentid=47526&stc=1&d=1338469994

[zul8tr]

First off your cold compression is low at 100. A solid 102 should pull 125- 130, so you are starting off low. Before the head I would check the cylinderes for true and fix that with oversize if needed and a new set of rings. When compression up to standard run it then pull the head a shave if desired. One thing at a time is a rule with mods.

As far as the the amount to trim can't answer that. First cc the combustion chambers to determine where you are at. Also note that if you trim too much you will upset the squelch area that is important to the loop combustion process. Others more familiar with modding the 102 will have to advise you on hoe much to shave off.

The head on the 102 is easy to pull off so no big deal to do it after other work.
Have you aligned the exhaust, cylinder block and crankcase to be dead flat to mate with the lower unit tower? Are all bolts properly torqued? See the manual for instructions at Rick Montoya's site.

[Jippe]

I have motor almost completely disassembled now. I have dremel and it has lot of job soon ;) Theres quite lot angles to round, casting is rough and bumpy. If I have go oversized pistons, do i have to bore cylinders? Manual says piston ring gap has be about 0.8mm but where I measure it http://www.boatracingfacts.com/forums/images/icons/icon11.gif
Also noticed that all cylinder holes are unfinished sharp edges with 90 angle. There should be bevels or roundings to save piston rings.

I take more pics parts later today, before do anything else than planing the head.

Where to get power reeds or material to make them?

[zul8tr]

Jippe

Please excuse my forwardness but by some of your questions it appears that some of your mechanic skills are lacking. Here are some questions and basics

What exactly are you grinding with the dremel? :eek:

Ring gap is measured with the ring removed from the piston and placed in the cylinder at the top then the bottom of the stroke in the same orientation as the ring would be on the piston and with a feeler gage measure the gap in the ring end.

If you go with oversize pistons the cylinderes must be bored to fit the pistons with the proper clearance between piston and cylindere wall. This is very critical and boring and honing must be done by a knowledgable machinest to get the proper clearance.

The sharp edges on the ports are normal per the factory but some rounding is ok if properly done with a dingle berry hone.

Power reeds can be obtained from Boysen, just google them.

[Jippe]

Only thing what is lacking is my english writing skills :p
I'm mechanist, working with elevators, installing and repairing them.
I don't have milling machine, turning machine etc. but I have know-how to use those and many more.
With dremel on exhaust side I polish all channels and remove bumps/uneven spots what cast left. On intake side do also polishing, edges rounding and some material removing.
I can't explain this any further so pics are coming later ;)

Boyesen dont have 302 reeds, I buy material local and make them myself.

[Jippe]

Pictures 1

[Jippe]

Pictures 2

[Jippe]

Pictures 3

[Jippe]

As you can see, theres lot of work for dremel :D

[Jippe]

Measured piston rings gaps and they are 0.5-0.6 depending on spot of cylinder.
I took one ring off and put it to cylinders different spots and measures with feeler gauge, is that procedure ok? I used upper piston ring and that same to all measurement.

[zul8tr]

Your procedure is as I described several post ago. Just make sure the ring in the cylindere is at 90 degrees to the cylindere wall. This is easily done with the piston (without rings) placed in the cylindere inserting from the head at the top and tap the ring into position at 90 degrees to the cylindere wall. Oil cylindere wall before doing this.

The ring end gap of 0.5 to 0.6mm is in spec. Max gap for replacement is 0.8mm per manual.

While at it check cylinderes for wear at several locations near top. mid and near the bottom of the stroke. Per manual maximum cylindere diameter for 302 is 2.602" and minimum piston diameter is 2.595" measeured at skirt on thrust side and 9/16" above bottom of piston.

[Jippe]

Per manual maximum cylindere diameter for 302 is 2.602" and minimum piston diameter is 2.595" measeured at skirt on thrust side and 9/16" above bottom of piston.
Pistons diameters are 65.6mm (2,5827") top and 65.8 (2,5906")bottom (both same)
Cylinders diameters are 65.95 (2,5965")top and bottom (both same)

[Jippe]

Where you guys buying yamato gaskets and other spare parts?

[zul8tr]

I get them from Tom Cronk here in Lakeland Fla.
http://www.hydroracer.net/forums/showthread.php?t=3641

Also Ric Montoya has Yamato parts.
http://www.yamatoracing.net/

There are others if you search

[BRIAN HENDRICK]

European dealer for Yamato is Rick Ward in the UK at;
http://www.yamatoracing.co.uk
He travels to most races on the continent, but I do not see any in Finland
You must work on that. Closest I see is Estonia, or Germany?

My experience doing a 1.5mm [.060"]cut on a 18mm 102 head
was that it caused the piston to hit the edge of the head.
One must restore that that outer band in the combustion chamber.

I have made 16mm to 15mm prop bushings in tool steel
Slow and difficult.
11/16" [popular US size] to 15mm is easy size to make.
Bore the 16mm prop out to 11/16" [17.4mm] and bush it back down to 15mm.

Since you want to stay quiet, and there are no rules,
I was expecting some one would suggest running a 'dry stack'
ie dry exhaust, by venting all cooling water out of the head.
This prohibited in NA stock classes, because of the performance gain
Mod classes are dry exhaust.

[Ron Hill]

Rick Montoya and Mike Ward......Montoya is the USA dude, Mike Ward is the UK dude for Yamato....mike@yamatoracing.co.uk (http://us.mg5.mail.yahoo.com/neo/launch#) Mike's email.

[Jippe]

Where to get shear pins? its 5mm diameter, what material it should be?

[Ron Hill]

I had a whole jar of them around here, I'll go look...

Stainless Steel welding rod will work. A good quality stainless steel bolt can be cut to length. The pin doesn't have to be rounded on the end!

[Ron Hill]

Seems, if I looked long enough, I'd find some shearpins for a Yamato....I've got damn near every **** in this drawer, but the drawer wins, as my finger tips give out easy with my old age!

Anyone see any shearpins??? If you do, I'll keep looking...I have one more drawer like this, somewhere, too!

[Jippe]

Exhaust cover has two water outlet: one back and down, one front and little bit higher.
That higher outlet is connected U-shaped hose and back outlet is nothing. Where to connect mark water outlet? Is both outlets important? Or can I block another and use only one outlet to mark water?

By the way, I bought 5mm aisi 316 threated rod to make shear pins.

Boat is almost ready to go the test drive... I'll post pics later.

What is the purpose of two water out- or inlet to carb on front? Theres no hoses connected...

[Jippe]

Now I have done testing with few props. My cleaver is still best to drive but I get only 6200--6400 rpms max. speed 59-60 mph. With two blade diam. 6 3/4", center 10" and edge 12" (bought from Bill number 4) I get 7100-7200 rpms max. 59 mph. Two blade prop slips more and do not accelerate as fast like cleaver. If I want buy tree or four blade cleaver which be able to get +7000 rpms. Do you have any ideas what specs that prop should be?
Hope you guys understand this messy text :)

This thread have pic on my cleaver, can modify it myself some simple tricks? Tips little shorter or front tips rounder or something like that? I still dont have any specs on that prop, its dewalds made.

dewalds prop pics on this thread http://www.boatracingfacts.com/forums/showpost.php?p=120393&postcount=35

[Jippe]

I has to idle sometime and then I wont got it plane easily and heres results.
Does it look bad? I drove back back but only half throttle. Dont have cylinder pressure gauge with me but pulling rope one plug place at the time both cylinders feel same...

[Jippe]

Different view angle :cool:

49988