Setting ignition timing procedure ?

[glen]

Ignition Timing

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G,day guys,
well i just want some info please fellas.
i have a 2012 40 hp short shaft jap spec mercury two stroke 3 cylinder/3 carb out board engine
model # 1040203HL

ok well here is the list of mods done to new engine.
1/ boysen carbon power reeds
2/shaved head 20 thou
3/irruduam spark plugs
4/lightened flywheel down from 3 kilo to now 1.4 kilo
5/d1 50 hp larger bore exhaust ,also have exhaust relief holes in lower leg,
6/merc spitfire 4 blade in 15 " pitch
7/ram stacks with tuning spacer lengths
8/50 hp carbs/manifold
9/run 100 octane fuel
10/tiny tach comercial rpm guage
11/ cut/fluted air vents in engine cowling for better breathing.
12/ disconnect rev limiter wire
13/ adjust carb throttle so now can get full throttle
14/removed 2 chokes for better air flow into carbs
15/this beast will use amsoil marine full synthetic two stroke oil mix
16/sport marine 200 hydro foil turbo cavation plate kit.
17/inline cleanble fuel filter.
18/high perf/volume water pump.


should i advance or retard it ??
and how many degrees would i move it to ??
whats the procedure of adjusting the ignition from start ??
do i use a timing light ??
thanks guys
cheers

[glen]

Throttle Body Velocity Ram Tubes.

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Gday all
i have just fitted to my 40/50 hp mercury some 45 mm long alloy velocity stacks from my mate Sam @ SQ Engineering in Endeavour hills,victoria.
wow do they look great!!

I thought I would post this up just incase other guys where looking for something similar.

i have modded and cut engine cover @ front to fit air vents,which then flow into the throttle bodies.
what a great job sam does,tolerences are very tight.
sam can make them any diameter and length for just about any application.
they come all polished up ready to go!!
please visist his website below.
http://s-86.com/s-parts-velocitystacks.html
http://www.thundercatinflatable.com.au/forum/showthread.php?t=3127

sam has some spare sets already made up ready for sale to suit 50 hp mercury/toyhatsu appliactions.
not only do these t/b ram tubes look racey and well made,they give the engine more capacity to breath by there increased flow rate,plus ou are lengthning the intake tract for some more low-med power range,plus the roar sound of the t/b can be heard much better as well.
a great buy,cheap to purchase,very well made.
im happy over the moon with triples sam made for me.
thanks

[zul8tr]

Are you still breaking this engine in? If yes there are proper steps to go thru. Below is a break in procedure I received from Jerry Wienandt for the Merc 44xs but applicable to your set up.

I can't tell you what timing setting to run, only careful testing can and perhaps someone out there has a similiar setup that can provide some initial starting points. Higher compression usually requires less spark advance from whatever it was from stock. To prevent piston melt down you will need to retard timing and richen up the carb mix. Also run more oil in the fuel. Then with test runs you will have to slowly adjust the carb and the timing in a systematic way so you can monitor the results by observation of the sprak plugs, piston crowns and decide on adjustment of timing and jetting. Take good notes.

Here is info on spark plug reading:

http://www.strappe.com/plugs.html

Here is some info on piston melt down:

http://www.boatracingfacts.com/forums/showthread.php?t=5472

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44XS Break-in Instructions by Jerry Wienandt

Install Powerhead in lower cowl on lower unit with new gaskets. Tighten down 16 ft. lb..
Recheck these powerhead studs frequently, as gaskets compress allowing loosening
of fasteners. If these fasteners are allowed to loosen, you may lose cooling water,
burning down powerhead.

Fuel & Lubricant:

Use premium quality, clean burning two cycle oil and Non-Reformulated Regular (87),
Mid-Grade (89) or Premium (91-93) unleaded fuel.
(No Gasahol, oxygenated or reformulated gas)

I recommend Chevron Two Cycle oil, TCW3, which is very clean burning at high oil ratios.
If you wish to run Synthethic oil, I recommend Bombardier (Sea-Doo/Ski-Doo) full synthetic.
Use Synthetic at same ratio only after break-in on mineral based oil.

Fuel / Oil ratio at racing rpms: 8 to 1 That's 2 qts. oil to 4 gal. gas Oil is cheaper than parts

Break In / Running:

During break-in, we want to load the motor, while not over-revving it. Keep it pulling, loaded.
Carbs are set at 2 1/2 turns rich on low speed. Set-up motor low on transom with
a large, easy to plane prop. Start with fuel per above, at idle to fast idle without going up on plane,
varying speed, for 1/2 hour. Be sure to check that its pumping plenty of water at this speed.
Speed up enough to get solid stream water out of "telltale" hose at rear of cowl...
Then gently get up on plane and run short racecourse… run straight at low planing speed,
back off for turn, accelerate gently to slightly different speed on straight. Run numerous laps
in this fashion, gradually increasing speed for 6-8 gallons of fuel used. Then adjust low speed on
carbs to get rid of "4 cycle", leaning idle down to 1 1/2 to 1 1/4 turns, depending on temperature…
Richer in colder weather… When carbs are set evenly, correctly, on low speed setting, motor
will come on plane with no flat spot, stumble or hesitation in giving it throttle. If it stumbles, go
richer on both carbs on low speed adjustment. NEVER, EVER give motor more throttle than
absolutely needed to get on plane, as motor may rev higher while cavitating, than actually racing,
which damages reeds and is hard on a cold engine. Bring it up to temp before running hard.

Main jets are .055". These jets are good for most racing conditions with fuel described above.
Jet up one size (.057") for running in very cold temperatures.

Failure to follow these instructions may result in stuck rings, failed rod bearings,
broken reed valves and / or other mechanical failures. Remember, this motor has
has a very fine hone finish and alterred clearances and bearing surfaces from stock.
This requires careful and lengthy break-in, but results in very good compression when
motor fully breaks in.

Running lean on carbs will cause failure of the crank train due to insufficient cooling and
lubrication of bearings as well as piston damage. Remember, only the "back end" is water
cooled, the "front end" , the crank train, is cooled and lubricated by the incoming fuel
charge (air, fuel and oil).

[glen]

g,day mate
thanks for your info and reply!
yep i have run total time 60 minutes so far,doing heat cycle's tests.
various rev range,warm ups,cool downs,25:1 premium merc two stroke oil.
so how do i go about setting ignition timing pls ??
whats base timing for 40/50 hp 3 cylinder/3 carb ??
thanks

[zul8tr]

As noted in Jerry's break in procedure have you run 6-8 gallons of fuel for break in? If you haven't do some more running. Is that Merc Premium oil a synthetic blend? You should not be using any synthetic oil for break in, only synthetic after break in as Jerry states.

I do not know the stock base timing on your engine. Look that up on line or ask the Merc dealer. A 2012 year engine should be easy to get that info. It probably requires a timing light to see the timing marks to be adjusted.

[glen]

As noted in Jerry's break in procedure have you run 6-8 gallons of fuel for break in? If you haven't do some more running. Is that Merc Premium oil a synthetic blend? You should not be using any synthetic oil for break in, only synthetic after break in as Jerry states.

I do not know the stock base timing on your engine. Look that up on line or ask the Merc dealer. A 2012 year engine should be easy to get that info. It probably requires a timing light to see the timing marks to be adjusted.
i have used so far approx 7 litres of fuel so far.
no,i use non synthetic oil merc premium oil,then use amsoil marine synthetic oil once run in.
so with higher compression,its better to retard ignition a little isnt it ?

[zul8tr]

I gallon about 3.8 liters so burn more fuel for break in. Yes higher compression probably requires less timing advance.

[glen]

hi again,yes i will burn more fuel for break in then,thanks!
today i warmed up engine,removed 3 plugs and did comp test.
after 4 long pulls i could only get 120 psi,117 psi is standard.
now i removed 20 thou on sat from machine shop.
so i thought i would got more psi that!!
the gauge must read wrong may be ??
the stock gasket 0.088 thou,i do have a new thinner tlti gasket which measures0.036 ".
i think i will borrow another comp guage tomorrow and try again.
i will also buy some 1 mm soldier to do a squich clearance test!!

[zul8tr]

How do you know 117 psi is standard compression? Sounds low. Have you ever CC'd the combustion chambers on all 3 cylinderes. If you did or do, an estimate can be made (knowing the CC's and cubic inches of each cylindere) that would be fairly close to what you should get as a minimum on compression.

Did any of that Amsoil synthetic oil get in there AFTER you stopped your short 60 min break in with 7 liters of fuel?

Has the engine seen top rpm during the short break in? Hope it was only a short burst.

[glen]

cause i read the work shop manual book it said so!!yes on all 3 cylinders mate
no synthetic used what so ever.
max rev for very short time was about 5,000 rpm

[zul8tr]

That's interesting manuals I am familiar with never state the compression psi just the max acceptable difference in psi between cylinderes.
Keep going with the break in, 5000 not to bad but follow what was the procedure in the post I provided above.

[glen]

thanks mate for your help!!