85 hp reed valves

[kfriesen]

My engine runs very rich at idle and once I give it more throttle it sputters for a bit until it clears then will run fine at WOT I have removed the reed valves and noticed some of the petals have a very large gap some up to 1/8 inch. Is this my problem? If not where do I go from here?

 

[Frank Acampora]

Re: 85 hp reed valves

Maximum stand open on reed petals is .010 inch. The reeds with more opening are bent and need to be replaced. You must not try to re-bend them straight and you must not flip them over.

You can salvage good reeds and vee blocks from almost any 3 or 4 cylinder Chrysler or Force engine. You can also buy aftermarket reeds made of fiberglass or composite materials. They are said to improve hole shot and overall performance. The supposedly do have a shorter service life than stock reeds. I have never tried them.

One of the companies is Boyeson. There are others but I don't remember the names.

 

[kfriesen]

Re: 85 hp reed valves

what are the common symptoms of reeds that are open beyond .010?

 

[pnwboat]

Re: 85 hp reed valves

Runs poor at lower speeds, hard to start.

 

[jerryjerry05]

Re: 85 hp reed valves





Gas spitting out the carbs too.
Picture of the reeds?
The pics are from a Mercury225
But they show a set of reeds that are closed the right way.
Te one pic shows a reed too far open.
I've go some spare reeds in the holder if interested??
Send me a PM.

 

[kfriesen]

Re: 85 hp reed valves

ok checked compression all three cylinders are at or very near 120psi. I guess my estimation of the open reed was a little off I checked with a feeler gauge and there are three that are open at rest but definitely not even .010 or should I replace anyway. So my next question is why does my engine sputter and cough when I apply throttle then after about 10 seconds it clears up and runs good at wide open throttle? Idles and trolls ok with intermittent stalling but that seems to be natural with older two cycles right? not sure what else to try. Maybe a marine mechanic!

 

[Jiggz]

Re: 85 hp reed valves

I can think of two possible causes for sputtering when throttle opens, improperly set air-fuel mixture screws and improper timing in that order. Read the link and synch sticky post and set the air-fuel mixture properly and if problem persists, verify timing.

 

[Frank Acampora]

Re: 85 hp reed valves

Check the oil recirculation system. This system is designed to burn off excess oil and fuel that accumulates during idle conditions and thereby improve the idle. If the small screens and reeds on the side of the engine are clogged, the excess will not burn off. THUS: when you open the throttle, the engine is rich and sputters until it clears itself due to increased fuel requirements at higher RPM

 

[kfriesen]

Re: 85 hp reed valves

Where do I find this oil recirculation system on my engine?

 

[pnwboat]

Re: 85 hp reed valves

Not knowing what year your motor is, the following diagram may not match your motor exactly but they're pretty much the same. Items 36 and 42 are your fuel recirculation system, or cylinder drains.

Mercury, Mercruiser, Force, etc. - POWERHEAD - FORCE 1988 85 H.P. "A" MODELS

 

[jerryjerry05]

Re: 85 hp reed valves

Yea a mechanic will help.Bring it by the house If your in Australia??
Send me a ticket and I'll get my passport dusted off and be right there.
The air screws, turn in till they just bottom out then out 1 turn and leave there
Set the idle at 1100-1200 then adjust in the water.
Should be 800 in the water motor warm.

 

[kfriesen]

Re: 85 hp reed valves

Thanks for all of your suggestions I will check all of this and let you know what I find.

 

[kfriesen]

Re: 85 hp reed valves

I checked the fuel recirculation system and there were two screens that were somewhat plugged. I replaced the reed valves but still noticed when I moved the throttle to the fast idle position the engine still ran a little rough and quite a bit of smoke but idles beautifully. Air screws are set at one turn out from lightly seated position. Next step is to put it in the water and see how it performs under load.