Increasing WOT RPM

[146C]

Dave you tried tightening then loosening the stud, keep going back and forward, use plenty of lube mainly to wash the thread out and she should come out.

Yes, also left it saturated with wd40 will try again tomorrow.

Dave

[146C]

FNQ, in a 20 to 25 conversion the shift shaft usually has an extension piece that fits onto the existing spline with a new spline at the bottom since its a no load linkage.

I fail to see however, that an alloy plate to raise the engine could be dearer than converting his current box back to long shaft or replacing it with another box to suit a long shaft application. Unless the replacement box came for $100??

Dave, heat, penetrating lubricant, scratching device and a mallet will get it apart. I had similar recently with a pair of XL Yammies on a cat and both extension housings were jammed on by salt.

Gotta love Jap engines mate, fantastic when they are new but don't try pulling them apart when they have a few years on them coz they are the worst of the bunch....

Cheers

I didn't end up getting a quote for a bracket/brace the few marine companies I spoke to suggested I not do this but recommended that the transom be built up with fibreglass. The quotes I was given were upwards of $1000. Second hand gearbox $400-$700 a couple of the service guys I had spoken with were very helpfull with regard to replacing the gearbox.

Thanks for tips.

Dave

[Splash]

Splash probably no better way, can get pretty close just by visual inspection.

cheers fnq

FNQ - At WOT, the throttle lever bush was not at full end of groove in throttle lever - but rather about 1.5" away from end of groove.

Does this imply adjustment is needed so that this lever bush is at end of travel at WOT position?

Splash

[BM]

Dave, I had typed a lovely long response but it vanished..

Anyway, long story short. Why were you told not to add a 25mm thick alloy plate to the boat to mount the engine?

I and an old hand in the trade have been doing this for 25yrs without a problem.

Did they suggest building up the transom with an extension piece and dowls??? If so, I have seen these fail and I saw one sink a boat (about 2 yrs ago in Melb). Saw the boat sitting in my mates workshop post recovery with the so called "you beaut extension with dowls" setup ripped off....

I'm sorry to sound arrogant mate but what I have suggested, we have been collectively doing for a very long time without incident or issue and whatever you have been told is absolute bullshit, no doubt to extract more money from you.

The choice is yours, but I'm giving you experience from a professional who isn't after your money.

Cheers

[Noelm]

yep, agree there BM, I have seen heaps of Boats with "jack plates" to raise the Motor height, and I have also fabricated a couple as well, as long as the existing Transom is good, then it will pose no problem, after making a few I have come to the conclusion that to buy a non adjustable one is probably the way to go, they are not too hard to make, but the standard "store bought" ones are not that dear, the adjustable ones start to get a bit pricey though.

[FNQCairns]

FNQ - At WOT, the throttle lever bush was not at full end of groove in throttle lever - but rather about 1.5" away from end of groove.

Does this imply adjustment is needed so that this lever bush is at end of travel at WOT position?

Splash

Having trouble visualizing the groove in relation to where the bush is but no matter, pull the induction baffle of the front of the carbs, select full throttle and peek in and spy the butterflies - if they are fully open or even a little past then you have as much full throttle as is possible.

cheers fnq

[Splash]

FNQ - See attached pics..

I have also checked the butterflies - fully open at WOT.

In the pic., you will see the bush at WOT near top of groove on lever - with about 20 mm left before top.

Do i need to adjust anything so that the bush meets top of groove at WOT?

Also, in another pic, you will see top of flywheel - with 3 threaded holes - what is supposed to fit inside these holes?

SPLash

[FNQCairns]

Hi splash the linkages are a concert between throttle and spark timing/advance, there is stricly no idle adjustment outside of mixture which is a poor way to do achieve it.
Because of this concert of linkages througout throttle range all designed to give you the correct idle at idle spark advance right through to full power and full spark advance as the linkages allow under throttle movement gaps like this are normal and esp so if you have viewed the butterflies at full throttle and they are fully open.

Those holes are for the flywheel puller.

cheers fnq

[Splash]

Thanks FNQ - My manual says I shoudl be idling at 600-700RPM.

I currently idle around 1000 - 1100RPM.

Best way to adjust this idle down on this donk?

SPlash

[FNQCairns]

It's hard to do it properly without a full link and sync, the spark advance at idle adjustment controls the idle speed. If it is idling too high then this points toward too much spark advance at idle which due to the way advance is linier on theses engine then the max spark advance will be too high also.

If what you say is how the mechanic that last touched the linkages and timing gave it back to you then he didn't do a very competent job, although sometimes owners think these are designed like a lawnmower carb in idle adjustment and go at it themselves.

If you choose you can adjust the carb stop to obtain a lower idle but it shouldn't be strictly necessary but it obviously is.

cheers fnq

[Splash]

Thansk FNQ.

Good memory mate. Yes a Linc/sinc was performed by a professional mechanical in Melbourne early 2007 - before rig came up here..

Where can i find the carb stop?

Splash

[FNQCairns]

Actually splash I think this is a place you had better not play with it's too much of a concert and because of the inherent risk of altering the timing not a nice place to adjust.

IMO pay someone it may be a simple cam adjustment needed or even a throttle cable but without seeing it work and how it rests in real time not worth the risk.

cheers fnq

[Splash]

ok thanks mate

[BM]

FNQ,

Just on the timing. If the pickup timing is advanced beyond where it should be this wont affect the max advance. This is because the max advance is a mechanical stop, so the pickup timing point has no relevance to the max advance.

Splash,

Make sure that at idle the butterflies are fully closed in the carbs. Also check that the throttle cam is just touching the throttle cam follower in the idle position. Most OMC engines from approx 1972 onwards had fixed jets so there is no adjustment possible on the carbs. However, certain models from time to time did come out with adjustable carbs.

If the above is how you are set up then your pickup timing needs to be checked. Easy to do if you have a timing light. Just run it at idle and check the timing.

Is it 1000-1100rpm IN the water? or on the muffs? Whats the in water idle speed?

Also is the tacho correctly set. Needs to be on 6 pulse.

And lastly, your model is likely to have quickstart (what year 110 is it again?). If one of the overheat sensors has a white wire with a black trace then you have quickstart. This wire goes back to the powerpack and it controls the shutdown of the quickstart condition and returns your idle from say 1200rpm back to normal idle speed of say 750rpm.

Quickstart advances your pickup timing to facilitate easier starting. With a warm engine when you start it the quickstart condition will last for about 10 seconds and you will hear the engine idle down.

Cheers

[Splash]

Thanks BM - Will check it out!

How do I check for if throttle cam is just touching the throttle cam follower in the idle position?

1989 is my OMC model.

No white quickstart wire sensor.

tacho on 6 pulse.

Cannot remember if idle in ocean , muffs?

Splash