ahh the Argo 17, i know these boats , they were around a long time ago, very nice boats,
the panther jack plate is nice and very expensive, certainly not under any pressure with just a 70hp motor.never seen one in the flesh.
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ahh the Argo 17, i know these boats , they were around a long time ago, very nice boats,
the panther jack plate is nice and very expensive, certainly not under any pressure with just a 70hp motor.never seen one in the flesh.
Try to start 1st time after build, cranks really poor on my old battery even it was fully charged. Will need fresh good battery to start her up, i think have quite much compression😂. Havent measure yet. Have to get that new battery first and try again. If it dont crank enough then have to open those little holes in the cylinders.
looks awesome !
if that is the head on there with small combustion chambers you probably wont start it without 24 volts.
I would be doing compression check before starting it up.
I do hope this runs good for you.
you have put a lot of work in the motor.
Be good to hear it run, I hope you have video ready for us to hear the beast running.
http://www.odysseybattery.com/batter...FZ24wAodg6QHIw
These batteries worked GREAT on our 45 SS, amazing cranking power.
I use a banner 75amp with 660 cca. Works a treat.
Damaged propeller gets a new job. Cut the plades few cm, can use as a testprop on boatramp.
Here it is! https://youtu.be/oPcqyNwOrxE
Funny how much better it works when wires are in right places. Tomorrow to the boatramp with that "testprop" and see how it run.
1. 145psi 2. 148psi 3. 146psi. Cyl.head temp aprx.60*c. Ign timing 2*btdc.
it is running hooray.
sounds nice and crisp 2 stroke ..good.
not high compression though ? why seems very strange unless the head was from a 50hp 3 cylinder ????
Higher exhaust porting yields less static compression pressure because less cylinder volume from TDC to top of port. Most stock 2 cycle outboards are about 6.5 compression ratio (CR) relative to top of exhaust port, if you raise the exhaust ports that lowers the CR relative to exhaust.
Thats the case. And scavening & cylinder filling when running rpms is another, it might have quite high dynamic compression.
Yes much greater dynamic compression that cranking, engine is dealing with a hopefully controlled burning fuel air mix that expands rapidly and if ignition timing correct and other factors the max pressure on the piston will occur near 10-15 degrees ATDC to push it down. Depending on a lot of conditions dynamic pressures could exceed 800psi
Zul8tr
you said
"Higher exhaust porting yields less static compression pressure because less cylinder volume from TDC to top of port. Most stock 2 cycle outboards are about 6.5 compression ratio (CR) relative to top of exhaust port, if you raise the exhaust ports that lowers the CR relative to exhaust. "
to counteract the raising of the exhaust port (40 thou) many things have been modified.
The idle reliefs have been closed off ? this should raise compression.
the head being skimmed ? this should raise compression.
and the combustion chamber itself being reduced to about 2/3rds its normal size ? should dramatically raise compression on its own..
these 3 factors should of raised the compression to far exceed that of the OMC SST60.
I think another known to be reliable compression gauge would be a good idea to know what is realy going on, simply because 145 psi is not
even close to what is considered a high compression OMC 56.
I would of been expecting atleast 175 psi, then bed in and make around 180 to 190 psi .
Good morning!
Engine starts nice and idles like nothing with forward gear. My "testprop" is awfully heavy when buried down deep, had to lift so that a/v plate is level with water surface. Ign on idle 4*atdc, max 17* now. 800rpm with gear. That prop shakes alot. Better have official version. Reacts nicely to throttle input especially over 3k, instant 7k when smash the pedal😬. Picture for plugs after few minutes in 6000rpm, not wot, then shut.
Sorry no video, alone in a ramp.
Hope it works when on the move and gets plane.
In my statement I was referring to a relative change in pressure with previously all else remaining the same. You are correct other things were changed so why the low psi? What was the compression pressure before all mods?
Not being familiar with your engine internals not sure how idle reliefs would affect compression psi.
Yes on head work to increase compression psi.
Redo the compression test with the cylinders oiled up to better seal the rings. If great difference the rings leak a lot, if not it is what it is by that gage.
Do a leak down test.
Yes possibly a different compression gage would give higher psi? Regardless because different gages will read different. I only use Bourdon mechanism type gages for relative differences in psi rather than absolute pressure psi and I always use the same gage to preserve the accuracy of relative psi measurement differences. Bourdon type gages are simple diaphragm expanding mechanisms that are calibrated to a standard using a dead weight tester or other accurate reference testers. Unless calibrated you will find differences among gages since you will not know the past history of the gage treatment and even new identical gages will read different.
I just looked at the picture of the spark plugs, why the thick copper washers ?
did you balance your testing prop ?
I had a prop that was terrible for vibration, once I balanced it there was no more problem.
but I also have a prop that when balanced is still crazy for vibration..
https://youtu.be/XZ6xrDQQnxw
Is this fourstrouking? Seems like there is pretty much unburnt mixture coming from exhaust. So something has changed😂. Hesitates in lower rpms like i think cause by overrich mixture. And then there is that stock tuner wich propably makes it feel kind of "liveless" on high rpms. That vibration i mensioned with "testprop" , its the engine itself.
Ignplugs threads are that much shorter now on the head.
https://youtu.be/mYgMwxCKJE8
Too much primarycomp might cause that unburnt mix going through engine?
HAH, my tach dont show over 7k, needle dont know what to do!😂
Took away stuffing i made around reeds, dont push mix to the exhaust on idle anymore. Those plugs i made for comp relief holes, same stuff as nosecone, are gone. Infact i think they were gone by the time i made comp test. Maybe thread and little setscrew. Went out today, ran 45.5kn with 18 raker, dont know revs cause needle stops little over 7k. Have some water issue, dont idle good on water or flushhose. Without better, might be headgasket. Is there a chance that headgasket blows with too much waterpressure? Little lazy for going on plane under 3k especially with raker, dont slip enough, but when nose go down then it goes. Feel like needs to start playing with tuner. But before that i try with srx how it works.
Sorry for tight typing😊
No it is not too much compression.
you are not firing on all 3 cylinders all the time. there is no crisp 2 stroke sound.
before on your older video showing boat going fast your engine sounded very crisp , very good.
what oil and fuel are you using now .
what are the plugs ? Champion QL77JC4 ? or Champion QL78YC .
you will always get some 2 stroke oil in the water from the exhaust, that is normal.
with 18 raker it should fly from zero. 18 is small for that motor . maybe need 12 to 13 mm vent holes, omc vents are too small.
have you tried with plugs and no copper washer ? it will let the spark be in the correct place to fire.
I also asked lots of people about the tuner to make it shorter, but everyone who is expert on tuners say you will lose bottom end power on v hull.
short tuner just for very light tunnel hulls. ?
It might run little better with QL78YC, tried both. Yes i know there is always oil in exgases but it was like pouring through before took stuffing out. It may have weakened lower end a little bit.
Think that transfer timing is too much, causing that lame lower rpm behavior
I run our 98e5 with some fully synthetic oil ment for bikes.
have you tried with extra spark plug washers taken off ?
Ordered J-B Weld HighHeat epoxy putty for relief holes and solved the water issue; What a dumbass I am, forgot to retighten the head bolts so they werent tight enough and water went to cylinder(s) and gasket was also broken between thermostat and #1. :o
I bet it run better after fixing those.
Good night everybody!:)
ha ha we all forget the simple things. the hard things we all remember, bu the re-torque the main head bolts we forget about .
glad you have found your water problem, you will be fine soon
Ill do that, thanks!
Have to find studs & nuts somewhere.
BTW Good Morning! :cool:
I have original mainjet now, dont remember what it is in those carbs. Made 1 WOT and shutdown, plugs look ok. Pulled head off last night, pistons seems like ok to me.
Have to do those reliefholes with J-B and assemble the head back, then can go out and drive more so that i can see how pistons look by the transferports.
Must get tachmeter wich shows to 8000.
Ouh yes, I replaced those reedbodies, wich Ive stuffed all around, with stock ones. It felt like fighting against itself in high rpms. Better now but weakened lower end, have to find that sweet middle.
And stock tuner in Place, still revs like hell with 18in prop.
There is some tuning to make.
Btw is it any good to use coppergasket spray with headgasket?
This is how pistons look. #1 is clean because of water.
Cool build :cool:
why not put a slightly bigger prop on and save it revving to the moon, there is no point revving the nuts out of it with a 18 pitch.
you were running the 23 before the work, you wont know if its any stronger until you try that prop on it.
How many hours run are on it now since new rings put in ? 3 , 5 ?
I will put 23 next time I go out. Its got only max 2h. Have to wait that J-B so it takes few days.
What a luck, we have 1 company here that sells it.
not sure even the jb weld will hold up.
if it is nice and smooth in the holes you have no chance of it staying there. needs to be rough inside the holes
I think maybe alloy welding is the best way, then the sleeves dont get a chance to warp with steel welding.
hope the jb weld does work, makes it a real easy job.