Losing power top end?

[03griz]

My 03 RX-1 is losing power top end. When it happens it will only do 95 M/H wide open. If you hold it 3/4 throttle it acctually feels like it gains a little, open it up the rest of the way it feels like it is losing power. Now here is the real wierd thing. Hold it open long enough (couple of miles) and it starts picking up speed till it is registering 114 or so. Did it yesterday and once it started to run good it worked good for half the day and started doing it again after stopping for an hour or so at a friends place. They have gone to ethanol blended in all our fuel now and I was wondering if this could have something to do with it. I am planning on pulling the fuel pick ups out of the tank to check the screens, also pulling the carbs apart. Should I jet up one size because of the fuel while I am in there? Just had the clutches all redone with bushings and whatever they needed. Any other idea's? Could the plugs or coils cause this? Sled also seems to serg a little when it is doing this. RPMS are around 9 when it starts this and a little above 10 when it startes running fine. It starts and idles well.

Thanks for any help you can give.

 

[Viper_Dave]

I would bet it is the screens. I have had similar problems with older sleds, and it seems every time it's the filter or screens in the tank. Have an 86 SRV that drove me BONKERS when it did this. You name it, I tried it. Fuel pump, carb cleaned, CDI, BOTH coils, etc. Finally pulled the filter in the tank, and it was almost completely plugged. Sounds very similar to waht you are experiencieing. Good luck

 

[grader]

when you pull the carbs remove the float, needle and seat. there is a small screen under there that can be removed. your plugs should tell you something about the fuel flow as well. if they are white or very lite its from lack of fuel. jetting up one size to 137.5 will help also. remove and clean coils inside and out with solvent or brake clean to remove carbon residue. also try a new set of plugs, as one bad one can do strange things.

 

[RX Buck]

You may be going after the wrong component. It could very well be the clutches. It seems to me that the secondary spring could be broken. If that happens the secondary will open right away causing the machine to shift into high gear to soon lugging the motor down. This would also explain why it takes a very long run before the engine can catch up to the gearing so to speak.

Just a though, check out the clutches before you dig into the engine.

Buck