WHY DOES MY BIKE REV SOOOO DAMN HIGH AT IDLE????

okay.. here's what i got...

1981 yamaha maxim 650
Carbs are 110/40 ( i recently had them cleaned)
the exhaust is cut off from the foot pegs back... (two pipes)
Intake is pod filter from ebay


THE PROBLEM: when starting the bike immediatly the rpms SKYROCKET so quick and loud i have to hit the kill switch immediatly.

( when i took it to the shop to have it checked they changed me over to 120/40 and it smoothed out alot but when you are riding, when you get on the gas it boggs down and you have to down shift....??)

i am thinking there is a vaccum leak coming from somewhere.. any ideas?

i think he chaged the jets to 120 to compensate for a leak?

 

To rev above 4,000 rpm's ... the Throttles are Open and Main FUEL Jet Supply is being used.

Somethings stuck open.
Wrong or tight Cable
Stuck Linkage.
Broken Wire in the Cable.

Stuck Open ... Diaphragm Pistons
Air Leaks
Manifold Leak
Petcock Membrane Leaking Fuel INTO Vac line.

Pick the way you like to ride.
With Pods and Open Pipes something has to suffer.

Changing Jets is going to be your New Hobby.
Read some of the archives on Pods and Pipes.

I hope you saved the airbox and boots,

 

what should i do? i dont have airbox.. didnt come with it and the exhaust sounds soooo beast! would it really be the exhaust causing issues?

i am currently running fuel directly from a gas can not a petcock

 

have you checked the float heights?

 

what will that do?

 

I don't understand. If you have to hit the kill switch immediately after starting, how do you ride it to know about the bogging down?

As Rick said, check your linkages. If it has been rejetted the throttle cable was removed and reinstalled. Last time I did that I had a really high rev upon start up too, all i had to do was adjust the throttle cable.

If you are bogging down that is likely a whole other problem entirely and we will need much more info about what is happening to help you. None of this "hitting the kill switch then riding it and bogging down". I don't know what is going on, but I'm pretty sure you aren't riding it with the kill switch in the off position.

Be thorough and specific.

 

Dood that many things modified becmes a guessing game for the best especially when it's reading and not "hands on" . first step is to do a complete carb setup. Check out Rickomatics posts on it and follow exactly. Cut corners and you don't know what you have when your done.

 

If the level is too high it can make it bog.

 

my carb had fire in it when i tried to crank it.. only pops and fire comes out of #1 carb

 

If you are running directly from a gas can then you are getting waayyy to much fuel,If i'm not mistaken,the petcock in the on position meters fuel via vacuum from the carb manifold...... A gas can would be like running in the prime position...

 

Had the same problem, My issue was a frayed ready to break throttle cable. The throttle sounded if there was sand in the tube. I twisted the throttle several times, added a cable lube and twisted some more, the cable then snapped. I replaced the cable and then the bike purred like a kitten.

Worked for me.

Rob