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View Full Version : 1989 110HP Johnson - Will Not Hold Idle



Splash
15-03-2008, 07:06 PM
Team,

What could cause this outboard not to hold idle after I return the Fast Idle Lever to it's rest position?

Splash

BM
15-03-2008, 09:16 PM
Splash,

After all the fiddling you have done with that engine it could be one a 65 zillion things.

Most commonly however would have to be:

1) spark problem be it coil or power pack

2) carby problem

Cheers

FNQCairns
15-03-2008, 10:48 PM
Splash try draining your carby bowls.

cheers fnq

Splash
15-03-2008, 10:53 PM
thanks boys

Roughasguts
16-03-2008, 05:47 AM
Adding to the above could be compression down on one, or more cylinders.
How are they now, didn't you re-use head gasketts there at one stage?

Splash
16-03-2008, 10:23 AM
hi Guts.

New head gaskets used.

I wil lcheck compression again.

Splash

Splash
16-03-2008, 10:24 AM
How would draining of carby bowls impact this?

Roughasguts
16-03-2008, 10:33 AM
Draining the fuel bowls, will let you know if they are full of fuel as they should be.

Or empty as 2 of mine where the other day meaning a stuck needle in the seat in two of the carbs.

Or full of crud meaning possibly a blocked jet. Just an problem elimination technique really.

Does it idle okay on choke possibly meaning blocked idle jet in one of the carbs, if she does.

Splash
16-03-2008, 10:35 AM
hi guts.

yes, seems to idle ok on choke.

i will drain the bowls and report findings.

thanks for help.

splash

Roughasguts
16-03-2008, 10:43 AM
No worries splash it's a bastard to remove the carbs just to blow air through the jets, but that's how they designed it.

Then you have to re make the gasketts after you scrape them clean.

Splash when you have removed the drain screws from the float bowls, squeeze the fuel primer to flush petrol through the float bowls.

And don't smoke while your doing it, unless the boat is fully insured and away from the kids.

Splash
16-03-2008, 11:51 AM
Roger that!

FNQCairns
16-03-2008, 11:57 AM
Yeah Like gut's says but also consider water, draining and flushing will eliminate it, we both live in grossly humid regions.

cheers fnq

Splash
16-03-2008, 02:28 PM
OK Guys.

Just spent all of that time completing that task :-(

95% of time spent searching for bowl screws dropped under powerhead, then digging out these f ckers and then trying to screw them back in without dropping them again ................. grrrrrrrrrrrrrrrrrr!

But, I did discover that only 2 bowls had solid flow out when I removed these screws. 1 bowl had nothing drip out and the other - small trickle!

I flushed all 4 bowls by priming and eventually I got good consistent flow across all 4.

When I started - defnite improvment! :-)

Idle was held very well and the sound of the motor defintiely sounded a lot better.

I think we have acheived something good today - really appreciated!

Splash

Roughasguts
16-03-2008, 02:40 PM
Splash that's a good thing, it's nice to have a win or two every once in a while.

How many filters you running before the carby's I got two a water seperator filter and a fine screen filter just before the fuel pump.

Splash
16-03-2008, 03:00 PM
Guts.

I have two filters - similar to you.

In the water separator filter I need some advice on draining water out.

I have the Raycor water seaprator filter. I can see water build up settling on bottom and in the center tube bit.

When I release the bottom plastic fuel knob, I don't think I remove any water because I still see it in both locations.

What is the correct procedure fro draining these things?

SPlash

Splash
16-03-2008, 03:02 PM
Splash,

After all the fiddling you have done with that engine it could be one a 65 zillion things.

Most commonly however would have to be:

1) spark problem be it coil or power pack

2) carby problem

Cheers

HI BM. In light of my tasks today, what other potential carby problems should I troubleshoot?

SPlash

Roughasguts
16-03-2008, 03:12 PM
Guts.

I have two filters - similar to you.

In the water separator filter I need some advice on draining water out.

I have the Raycor water seaprator filter. I can see water build up settling on bottom and in the center tube bit.

When I release the bottom plastic fuel knob, I don't think I remove any water because I still see it in both locations.

What is the correct procedure fro draining these things?

SPlash

Splash that's all I do is completely screw out the fuel drain in the Racor, maybe bounce your boat from side to side to get that water out and settle in the bottom if you can. But it would be bugger all left in the filter and won't harm anything unless that filter is half full of water.

Splash
16-03-2008, 03:27 PM
Thanks Guts - What is that center tube for anyway - I can see at least 1" of water in that center tube which is about 25-30mm diamter.

SPlash

Roughasguts
16-03-2008, 04:04 PM
Got me thinking now I'm at work, boats at home isn't that center tube the bit that screws on to the inside of the filter. But are you sure that's water, and not air.
Bugger now I have to investigate when I get home.

Splash
16-03-2008, 04:05 PM
Ok - I have just pulled of fmy Racor Filter adn emptied it - discovered a whole lot of CRUD at bottom an dinside center tube. It was not water at all.

I intensely flushed the filter with spare petrol and re-installed it. I guess, we can conclude that the filter is dong it's job... :-()..

Splash

Splash
16-03-2008, 04:08 PM
This tube like center bit is about 30mm diamter I think. If you take filter off and look down into filter from top. You will see the bottom of the filter/transparent bowl. You are now looking down into that center tube.

Splash

Splash
16-03-2008, 04:09 PM
Guts, what other potential carby problems should I troubleshoot?

Splash

Roughasguts
16-03-2008, 04:23 PM
The only problem you get is dirt and water in the carby.
So keep the fuel, and filters clean prime the fuel bulb every few days to keep the carbys wet and gasketts from drying out.

Drain and flush your fuel bowls if you haven't used your boat for a while, as you just done and you should never have any problems. But the trick is once it's running good don't adjust any mixture or idle screws or linkages just clean and lube once in a while.

Splash
16-03-2008, 04:28 PM
Thanks Guts - What is that Center tube for?

How do I know if it needs re-adjustment (mixture/idle screws/linkages) in the first instance?

Splash

Roughasguts
16-03-2008, 08:49 PM
Splash mixture and idle setting will never go out of adjustment unless you completely strip down and clean the carby's and remove all the adjustment screws for cleaning. You can still strip down and clean the carbys but don't remove or turn the screws and the carbs will be fine, Slightly worn maybe but still fine.

If somehow you do play with them apart from don't touch them.
It's just a mattter of finding the settings in the service manual, then turn the mixture screw in until lightly seated and count the amount of turns out that it say's in the manual EG: 1.75 turns out from lightly seated.

That easy, but I find it's best not to try and fix something that isn't stuffed. Because then you will probably never find the fault, probably being minor and then actually making it worse by fiddling with every thing totally un related with the actual problem.
So remember those setting will not come out of adjustment by themselves.

Mate I don't know what that tube is I can't remember how it looks but I suspect it's just a plastic casting for the water seperator and drain to work nicely.

Splash
16-03-2008, 08:59 PM
Thankas mate.

I luv your avatar - your wife?

Roughasguts
16-03-2008, 09:05 PM
Splash She ain't me wife but I wish ........................I could remember who she was, somehow her face didn't make it in the photo.

Spaniard_King
16-03-2008, 09:09 PM
Splash, you are playing with an area that would test most good mechanics. Now i don't doubt your enthusiasm but really I think you are expecting too much for this problem to be diagnosed on a chat forum

FNQCairns
16-03-2008, 09:09 PM
OK Guys.



95% of time spent searching for bowl screws dropped under powerhead, then digging out these f ckers and then trying to screw them back in without dropping them again ................. grrrrrrrrrrrrrrrrrr!

Splash

Mate thats a right laugh, I know exactly what you mean, done a little too much work breaking my body for the man so have minor tendon probs around my hands, will never be a brain surgeon thats for sure, anyway thanks for the laugh.

good to hear it is now going Ok.

cheers fnq

PS did you end up with fuel dripping from your elbows!! hate that>:(

FNQCairns
16-03-2008, 09:15 PM
The only problem you get is dirt and water in the carby.
So keep the fuel, and filters clean prime the fuel bulb every few days to keep the carbys wet and gasketts from drying out.

Drain and flush your fuel bowls if you haven't used your boat for a while, as you just done and you should never have any problems. But the trick is once it's running good don't adjust any mixture or idle screws or linkages just clean and lube once in a while.


Second this good advice.

Splash what isthe problem now with the way the engine is running over and above before you got some water in the carbs?

cheers fnq

Spaniard_King
16-03-2008, 09:18 PM
So I guess an air leak is out of the question hey :P

So let me see.. only runs on choke.. is that too much air or not enough fuel :P

Roughasguts
16-03-2008, 10:14 PM
So I guess an air leak is out of the question hey :P

So let me see.. only runs on choke.. is that too much air or not enough fuel :P

Garry not enough fuel, with the choke on the engine will be sucking the fuel past the sticky needle and seat on the dirty carbs. Alright for idling but won't run much past those rev's.


cheers

Spaniard_King
17-03-2008, 04:52 AM
So if it's an Air leak on the engine side of the carby it still not enough fuel hey???

Splash
17-03-2008, 07:05 AM
Second this good advice.

Splash what isthe problem now with the way the engine is running over and above before you got some water in the carbs?

cheers fnq

Hi FNQ.

The engine defintiely revs a little higher, but more consistent, smoother and actually sounds like a 110HP motor now..:D

It was an obseravtion I made as an afterhthought - crud in filter/separator (and not water). I have not run the donk since I flushed the filter out though...

Thanks boys!

SPlash

Noelm
17-03-2008, 08:25 AM
way way way back, I suggested that this Motor needs a PROPER service by an 'old time" OMC Mechanic to just get it back to fully standard tune and a known good state, so in the light of the pages and pages of stuff been done on this Motor, a trip to the "Doctors" would probably have paid for itself 20 times over by now, I do not for one minute suggest that home repairs are not to be done, BUT if it has been a drama for so long then continued "tinkering" will never get it fully operational, and may even cause a Major failure from a lean burn condition eventually!

Splash
17-03-2008, 08:44 AM
Thanks Noel.

I will do that now- although it won't be with an "OMC" mechanic - just a standard marine mechanic - no choice up here in Gove.

As I am now confident I have tinkered enough to get the donk up to a satisfactory basic level of performance - a mechanic can now fine tune the beast.

Splash

Roughasguts
17-03-2008, 11:05 AM
So if it's an Air leak on the engine side of the carby it still not enough fuel hey???

Hope your not trying to have a go at me.

Not sure I under stand the question Garry, If it's an air leak between the carbs and the crankcase manifold side, then you will probably get back firing. And sure it won't suck the fuel through that well either but it will also be a lean mix, and that ain't good for the tops of pistons.

If it's an airleak between the fuel tank and the carbs, that's easy to test and see if fuels getting up to the carbs. All you need to do is after you have drained the carbs pump the primer again and see if it fills the carby float bowls and if the primer stays hard after putting the drain screw in then yep theres little chance of a leak.

Not saying you never get an air leak on the hoses between tha tank and carbs You sure do. That blue plastic braided fuel line goes hard and brittle and can't hold a seal on the brass fittings, once you can twist it on the fittings throw it away and get some new stuff.

The leaking hoses and fittings, and filter seals would be one of the major causes of fuel problems on a boat. But if you feel like testing that remove the hose from your fuel tank and remove the fuel hose that branches off to your carbs.
Then hold your finger over the carb end to block air comming through, and suck on the tank end of the fuel hose once there is some vaccum there hold your tounge on the hose, if it' stays there sucked up by the vaccum then theres no leaks. If it doesn't then theres your problem.

And watch for the gob full of fuel, don't inhall the stuff something similar to bum sucking a smoke.

Cheers Justin.

Roughasguts
17-03-2008, 11:29 AM
Mate thats a right laugh, I know exactly what you mean, done a little too much work breaking my body for the man so have minor tendon probs around my hands, will never be a brain surgeon thats for sure, anyway thanks for the laugh.

good to hear it is now going Ok.

cheers fnq

PS did you end up with fuel dripping from your elbows!! hate that>:(

Got to admit I spent more time looking for me tools or the bolts I just put down than actually fixing something.

But heres a tip with your carbs and the drop zone.

Get an old rag and stuff it under the carb your working on then drape it over the screw drop zone, and over the lip of the out board engine cowl.

Now you got yourself a nice little net to catch your circlips tiny screws and tiny hose clamps.

Splash
17-03-2008, 12:25 PM
thanks Guts.