carb prob. '97 scrambler 500

[scotthawk55]

My 500 scrambler '97 will not run above about 25mph the carb slide does not go all the way up when the throttle is all the way open it will come up about half way and the rpms won't come up the diaphram is not torn the carb is clean in the book it says the slide should not be worn or have excessive play mine has wear just don't know how much is to much don't wanna replace it if this is not the problem has anyone seen the slide cause a high speed problem? If i use a screwdriver to push the slide up the rest of the way while at full throttle it will rev up all the way. By the way I have checked all the odvious possibilities belt, clutch, timing, plug, air cleaner, fuel pump, even shortened the spring that holds the slide down. Any help would be greatly appreciated.

Thanks
Scott

[2muchquad]

What about the throttle cable itself?Is that a cv carb carb that works off vaccum?If so you could have a whole in the hose that the carb gets the vaccum from.or theres arubber diaphram on top of the carb that could have a tear in it.Start eliminating the possibilities one by one.It shouldnt be too hard.;)

[scotthawk55]

Thanks for the response. Yes it is a vacuum carb and I checked the diaphram for leaks and all hoses are new although the hoses coming and going from the carb do not deliver vacuum to it the only one that has any vacuum is the one that supplies the fuel pump with it vacuum the others supply fuel and vent the bowl. I have eliminated all possibilities that I and the manual can come up with. I worked for our local polaris/suzuki dealer in 97 as a mechanic when these bikes were new and have a very extensive mechanical back ground, I think I have it figured out but was just trying to get an opinion from someone if there is anyone who may have had a vacuum slide wear out that caused a simular problem, and if they replaced the slide and had success. When I worked for the dealer we didn't see very many carb parts worn out mostly belts and pistons etc. ya know the easy stuff lol.


Scott