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'02 RM 85 jetting

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I currently live at sea level in southern ca.

When I roll on my throttle, there is a gurgling build up then as the bike gains momentum it seems to get through it a pulls well up top.

Is this a pilot jet issue? would it be too big? Does richer = bigger? Do I need a smaller pilot. Are pilots called a "slow" jet?:bonk:

Thanks for your help.

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Many people mistake carburation or jetting problems with needing a new top end.

I see this every day.

When I tell people this I usually hear, "We just put a new piston and rings in it".

Sometimes you can put a new piston and ring in a bike and it's fine.

If your bike is more than a few years old a piston and ring job is not usually enough.

A cylinder can look great and even pass a quick mic job.

However, unless you have experience with a mic and unless you have a decent set of mics that are properly calibrated you are better off letting someone mic your cylinder who has the proper experience.

A measurement of .0005 (4-6 times smaller than a hair off your head) or less can be the difference it a cylinder that can seal with a new set of rings and one that wont.

If your cylinder does not pass a careful inspection, then it will need to be repaired and re-plated or sleeved.

Once your top end is correctly repaired, do a compression check.

If it does read at or better then factory specs, no amount of jetting will help, really.

Also, be sure your reeds and exhaust valve assembly are clean and in good repair.

Last but not least, check your Carburetor boot to be sure there is no cracks.


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