[img]i/expressions/face-icon-small-happy.gif[/img] Hello all. I know someone out here has run into this problem, and maybe this will save me some time trying to get it lined out. First, after fixing a leaky base gasket, my machine idles perfect now. Here is the problem. When I ride, the rpms want to hang until the motor pulls down to a certain rpm, then it justs falls back down. You can also make this happen in neutral after gassing it. If you grab the carburetor with your hand, it will stop as well.I am running an open air element, and it does have almost new race mounts all around. It seems like the carb is air-aiting (is that spelled right?), but I have adjusted in between the idle mixture and air screw until i'm blue in the face. I know I must be missing something, so please someone who has had this problem before tell me how it got fixed. I might call mike at HPD today as well. Thanks for the help. I know that is what we're here for. Bubba[img]i/expressions/face-icon-small-smile.gif[/img]

 

you might have an air leak, grab a can of carb cleaner and while the machine is running spray around the carb and a where ever else you want and see if the idle goes up

 

Hey Bubba, I think especially with the big bores, there been a tendency to damage reeds. I'd take 'em out, and have a look. Also, turning a propane torch on low, and working it around the carb/intake, is a little cleaner than the carb spray....that works also.


Ken

 

Ken, just finished putting it all back together tuesday night. I did look very closely at the reeds since they are carbon fiber.I guess I didnt explain myself good enough on this problem. It runs perfect. The problem only happens after say 4500rpms. The motor just hangs there at that rpm. There is not an air leak. I can idle it down to a 1000rpms and it does perfect. It did not have this problem with the airbox on it. And remember, I can steady the carb with my hand and the idle returns to normal. I am pretty baffled about this one, as I am not one to give up. Thanks again,Bubba

 

bubba297,it look like VERY similar to the problem i get right now,my engine do the same thing after getting peak temp,i'm running my scram
at 1150-1160 degree (in midrange position),was told by hot seat to not exceed 1250 at wot,1000 degree in the midrange is the right tuning,i'm now to think (i run filtercharger also,no airbox) maybe the carb is
"shaking,twisting" too more and it make it dysfunction,plan to make something to hold tight the carb (probably better for the boot intake) right on soon,that the only guest i see for now...

 

Bubba,

Just an educated guess, but the idle stop screw, adjusted too far in, will sometimes make a carb do that. Try loosening up the idle screw and adjusting you're air screw. That might do it.

 

[img]i/expressions/face-icon-small-smile.gif[/img] Mike, already been adjusting between the stop screw and air screw until I just gave up. If I go any more on the air screw, the idle starts getting to lean and smooths out. This is really getting the best of me. Bubba

 

I did what Mike is talking about once. Before the quad was running, I turned in on the idle stop just a bit becaus the time before it was low. Then the first time I touched the throttle , it hung. Just another couple of things to check. Are you running a single throttle cable, if not, maybe the choke cable is hanging. Also when was the last time you lubed your throttle cable? Not sure if this helps, but in writing sometimes it's harder.

Good Luck, and please keep us posted.

Ken

 

Hey Ken,

Bubba said its a brand new thottle cable and is silky smooth.
He talked to rick today and he said that it might be the vibrations
of the bike causing the fuel to foam up on the carb.
I guess he will try to secure the carb in some way.
( I might have to help.... haaahaaaa)
I was curious as to when you will be at St Louis, I know you mentioned
it earlier. Will there be a race going on?
Bubba and I are about 6 hours away, and wouldn't mind going up
there to race or watch[img]i/expressions/face-icon-small-cool.gif[/img]
Bubba has gotten his bike to run extremly good, I won't ride it on the
pavement, just in the grass.
It feels as torquey (misspelled) as a v-max 1300 motorcycle that
I drove just a few days ago....
It is nice feeling that power in between.. uhh Nevermind[img]i/expressions/face-icon-small-shocked.gif[/img]

See ya
Dana

 

i had a problem like that with my throttle cable, it really doesnt matter if its a new cable, it might be loose and only pulls out enough to get 4500 rpms, thats why it hangs in neutral, try is neutral, taking the seat off and/or taking the cover off the throttle , and pulling it by hand, see if that does it for you, or it could be a problem with electronic throttle control, but i doubt it

- dan