96' ocean pro 200 wont turn full rpm

[liquidcommotion]

I have been trying to figure out after sea trial and sea trial to figure out my problem here is what I came up with today in the yard. I put the ears on ran the boat to temperature set the throttle up to 1500 rpms, on it's own it would go to 2500 then back down to 1500 maybe 15 to 20 second intervals, I was noticing a slight pop so I removed the carb cover and realized that my #1 carb or carb leading to #1 cylinder is backfiring I am guessing this could be the reason for only 4900 at top end instead of 5300 like it used to be. Any Idea what would cause this, timing is dead nuts triple checked. Also what would cause the engine to wobble between 1500 and 2500 like that? I dont beleive I ever boosted the rpms above idle out of water before so to me this might be normal? Thanks

 

[jonesg]

Re: 96' ocean pro 200 wont turn full rpm

Whenever I see rpm hunting I look for air leaks first, they can be anywhere from head gasket to carb gasket to fuel line couplings.

Pressurize the fuel bulb and examine the fuel feed with a flashlight closely, look for raw fuel or wet fuel hoses around any coupling such as fuel pump.

Try a compression test to eliminate the head gaskets.

Even a loose sparkplug can cause this. But you would see an overheat condition too.

Examine the recirculation hoses as part of this service too.

 

[SparkieBoat]

Re: 96' ocean pro 200 wont turn full rpm

back firing?? is the carb flooding from a stuck needle valve?? also check carb gasket. then check your reeds maybe.

 

[liquidcommotion]

Re: 96' ocean pro 200 wont turn full rpm

Allright I hunted swapping carbs and coils trail and error, I got it all the way down to the reeds and found my problem, my reeds in the #1 port were burnt up pretty good all else are great I found a blockage in what looks like a "jet" to me maybe for air maybe for fuel I believe it is for fuel it had granules of what looked like hardened rtv stuffing it full. Could this be the problem for my reeds burning up what would cause them to be so black and burnt? In this particular engine I have a reed block "part number 397336" the seats for the reeds is a plastic block and was burnt to where the reeds would not seat otherwise the reeds themselves look fine except for the burn of course. Any Ideas? Maybe a timing issue? Timing was dead on but I have been told maybe a spun flywheel or the magnets on the flywheel could be loose? everything helps so far progression has been smooth with the help from this forum. I found if you need parts or diagram for these motors you can go to ishopmarine dot com and they have it all the diagrams are really helpful.

 

[liquidcommotion]

Re: 96' ocean pro 200 wont turn full rpm

also how do i check for a spun flywheel or magnets or whatever it might be

 

[jonesg]

Re: 96' ocean pro 200 wont turn full rpm

A clogged jet made it run lean, running lean is same as advance timing, so it looks like it was backfiring thru the reeds due to over advance.
(jets are for fuel, carb throat is for air )

At this point I'd rebuild all the carbs, install a water seperator and test run it again.

To test flywheel you pull it off but I think you already nailed it anyway.
I wouldn't bother unless further problems crop up. I doubt it.

 

[liquidcommotion]

Re: 96' ocean pro 200 wont turn full rpm

this "jet" I was referring to was not in the carb though but in the intake manifold, it looks like it would be the only link between the 1st and 2nd cylinder. that's why i say it looks like a jet but probably not it's the only cylinder that has this? not sure hopefully you have good knowledge of this particular intake manifold

 

[Knightgang]

Re: 96' ocean pro 200 wont turn full rpm

Don't worry about the flywheel and timing at this point. Rebuild the carbs, replace the reeds, double check all connections to ensure fuel is clean, flows freely and has no airleaks... Ithink onc eyou do all of that (maybe replace plugs) you should be good to go. I bet it fixes the problem...

 

[jonesg]

Re: 96' ocean pro 200 wont turn full rpm

ditto that.