Possible Valve Problems

[dmoff1698]

:sick:Hey, I need some professional advice here.

I have a 99 RSV with 98K on the clock. The bike is running smooth and strong, but since it had been over a year since I had checked the carb balance I thought now would be a good time.

 

After warming up the bike, I hooked up the gages and to my suprise I got some really strange readings. Both of the left hand cylinders were reading close to 12 inches of vacume which I would expect to be low. The two right hand cylinder readings were swinging so wildly they were totally unreadable.

 

Thinking there may be something wrong with my gages (?two of them?) I swaped them around with the same results. I slowly increased the RPM and at what I judge to be around 1300-1500 RPMs the right hand gages suddenly stabalized and read within a couple inches of the left side (12 inches). Returned to idle and the gages started swinging again.

 

Now if this were my car, I would say that only 12 inches of vacume was late ignition timing or a vacume leak. With electronic timing and multiple carbs probably not. The wildly swinging gages would indicate a burnt valve, but a valve that bad should be detectable in the way the bike runs. And two valves on the same side at the same time is a bit of a stretch.

 

Can anyone point me to a solution? What vacume readings do you experience.

[tazmocycle]

have you done a seafoam or techron flush on your bike? fill up your tank with gas and a can of seafoam or techron, take it out and run the snot out of it for the full tank. after that change the oil, check your plugs and then see how it run after that. the 2nd gen motors are bad about carboning up if you don't run it a little hard evrery once in a while. also run couple of ozs of seafom or techron about every 2 or 3 tanks to keep it clean.

[Guest DragonSlayer]

10 to 12" of vacuum is about right for this bike at idle. When you swapped the gauges did you swap the hoses with them or just move the hoses at the gauges? Sounds like you may have missing or mis-adjusted restrictors in two of your hoses. Without restrictors in the gauge hoses they will swing wildy.

[Freebird]

Also, you might just try going ahead with the sync. They can get pretty erratic if they are out.

[dmoff1698]

Thanks for the input.

I'm glad to hear that my basic vacume readings are in the normal range.

I normally run seafoam or similar about twice a year, and very seldom push the bike hard during rides. So maybe the carbon idea is right on target. I have noticed a slight decrease in mileage lately.

I think what you are really trying to say is that I'm not having near enough fun.