won't hold idle and runs horrible at low rpm after warmed up

[scran0801]

My bike ran flawless when i got it. After repainting bike and doin some body mods the bike wont idle and runs horrible at low rpm and low speed after warmed up. Wont hold idle while cold or warm.have replaced vaccum lines to carbs and fuel line from tank. Has new plugs in it also.please help this is my first bike and my baby is broke

[Blaine]

Sept 6, 2013 19:01:26 GMT -6 scran0801 said:

My bike ran flawless when i got it. After repainting bike and doin some body mods the bike wont idle and runs horrible at low rpm and low speed after warmed up. Wont hold idle while cold or warm.have replaced vaccum lines to carbs and fuel line from tank. Has new plugs in it also.please help this is my first bike and my baby is broke

How long was it sitting? Your carbs may be gummed up.Try some SeaFoam in a tank of fresh fuel.

[scran0801]

Seafoam was my first attempt at a fix then went on to replace lines. Took bowls off and disnt find any trash and then checked diaphrams on top.my gas cap hisses all the time also and can also smell strong odor of gas at the gas cap

[Blaine]

Sept 6, 2013 19:55:01 GMT -6 scran0801 said:

Seafoam was my first attempt at a fix then went on to replace lines. Took bowls off and disnt find any trash and then checked diaphrams on top.my gas cap hisses all the time also and can also smell strong odor of gas at the gas cap

Open the cap & see if she runs better.......If so the vent in your cap is blocked.

[scran0801]

Did not think of that one. Very good idea. I will try that and let you know. Thanks for the replies

[scran0801]

I took carbs off and removed everythin i could remove spayed all passages out with carb cleaner and all was good. Left gas cap open like u said and it seemed to have a tiny difference but it still wouldnt hold idle and idle still doesnt come back down as quickly as it should after revving the engine. Any chance this could be electrical? I noticed several times at high speed my temp gauge jumps up and down and when just cruisn it holds steady

[eaglerider]

Just spraying with cleaner, and lot of times, Seafoam in tank will not clean all the orfices in the jet tubes. You need to remove the jet tubes and make sure all the little holes are clear.....I believe you have a carb problem.

[scran0801]

I did like you suggested and removed jet tubes and pilot air screws and sprayed until clear. There was some dirt that came out but when put back together and warmed up and cold no idle and while warm it ran like it was loading up at stop lights and rslow speeds

[zekkfett]

Sept 8, 2013 19:21:57 GMT -6 scran0801 said:

I did like you suggested and removed jet tubes and pilot air screws and sprayed until clear. There was some dirt that came out but when put back together and warmed up and cold no idle and while warm it ran like it was loading up at stop lights and rslow speeds

Did you do the pilot AND main jets?? The pilot jets are what controls the idle, and those holes are MUCH smaller than the main jets. If you play guitar, or know someone that does, the smallest E string works WONDERS in cleaning the pilot jets.

Other than the jet issues, perhaps your carbs are out of sync...

[scran0801]

I made sure carbs were in sync also when i started. I will tear it back down and do the main jets. I couldnt get them out yesterday because it looks like sumbody stripped the slot out where the screw driver rests down in the main jets. I appreciate all your time and help and knowledge by the way. Our little local bike shop refused to work on it so this site is my only hope

[scran0801]

It took some doing but got the damaged pilot out and size 35 jets to replace the 35's i took out. The damaged jet had a chunk of brass down in it.dont know how its been runnin at all. The main jets were size 125 and since im runnin modified exhaust and getting k&n air filters in the mornin i got sizes 128 and 130 to try in the main jets. Stock pilot was 32 i beleive and stock main's were 120. I may not b correct on stock sizes but thats what a few sites had listed as stock. You guys think these jets will work with modded exhaust and k&n's? Im tryn to figure out how to post pics of my bike on here also but cant figure out how to from my phone yet lol

[eaglerider]

I do not recommend K&N filters....way too much airflow for this engine in stock configuration......we have found that EMGOs work better. I would go to 135 on main jets. It depends on where the bike was sold new as to what jets were put in as "stock" jets. Don't believe that posting pics from phone will work.....using a computer and our Image Host is easy.

[scran0801]

I already paid for the k&n's when i ordered them yesterday or i would use the filters you recommend. I seen the plastic cone mod to use with the k&n on this site so u hope it turns out ok. I also appreciate the jet size info because i was concerned it was gonna be way to big and turns out im pretty near where it needs to b. I will let you guys know how it all turns out tommorow.

[lamestlame]

How did it come out?

[scran0801]

You were exactly correct on the k&n filters . Way to much air flow into carbs. Gotta order emgo. What size filters do i order?

[Blaine]

Sept 12, 2013 10:48:28 GMT -6 scran0801 said:

You were exactly correct on the k&n filters . Way to much air flow into carbs. Gotta order emgo. What size filters do i order?

54mm.

[scran0801]

Thank you so very much sir! Thank all you guys for your help. I taped off almost the entire surface area of the k&n's to get it running right by the way. I will ask before i leap from now on.