Yamaha 200HP, No Power

[Raven]

HELP! My 1996 200HP will barely run pass idle RPM. When advancing the throttle it "bogs down" about 1200-1500 RPM and further advance it will quit. It had been doing this intermittantly in the past but quick throttle movement would get the RPM past this. The fuel pumps are new and plugs are relatively new. This is a carbed engine. Any suggestions on where to look will be greatly appreciated. Thanks!

 

[consie67]

Re: Yamaha 200HP, No Power

HELP! My 1996 200HP will barely run pass idle RPM. When advancing the throttle it "bogs down" about 1200-1500 RPM and further advance it will quit. It had been doing this intermittantly in the past but quick throttle movement would get the RPM past this. The fuel pumps are new and plugs are relatively new. This is a carbed engine. Any suggestions on where to look will be greatly appreciated. Thanks!

Raven, I have the exact same problem-did you get any help? thanks, Cons

 

[Ray Neudecker]

Re: Yamaha 200HP, No Power

New fuel pumps and a good carb cleaning and rebuilding is the normal cure for this problem. Also replace the fuel water seperator filter. all of the signs are of a fuel restriction.

 

[Dark 30]

Re: Yamaha 200HP, No Power

I just came across the exact same problem on a 1998 yamaha 200 this weekend... Did anyone find anything different than from Endigns diagnosis??? I will sleep better between now & Tuesday if that is all it is??? Mine would also idle rough & die...

Thanks!!!

 

[rodbolt]

Re: Yamaha 200HP, No Power

test the spark and compression, if they pass find the fuel issue.
if the crank position sensor fails it loses 2 cylinders.
if a pulser coil fails it can lose 4 cylinders. also for rough idle with no other issues check the recirc valves that are pressed in the block.

 

[Raven]

Re: Yamaha 200HP, No Power

It was the carbs!
I removed and dismantled all three carburators and two of them had blocked or partially blocked "pilot" jets. Other than that the carbs looked pretty clean for a 10 year old motor. Carb kits are ordered but had not arrived so I had to reuse the existing gaskets/parts. Now that I have some experience under my belt doing a proper rebuild when the kits arrive should be a piece of cake.

Additional Comments: Compared to the many carburators I have rebuilt in my youth these are extremely simple devices; no accelerator pumps, automatic chokes, etc. The fuel delivery system is also uncomplicated: Two fuel pumps which "suck" the fuel through a filter bowl and fuel lines from the tank. The previous problem has now been eliminated and the motor also starts and idles much better than before. I have reset the pilot screws to 1 1/4 turns. My final question is this: Is there a technique for fine tuning the idle adjustment screws? .. or should I leave well enough alone since it seems to be running fine?