Carb issues

[vmax2extreme]

I was out riding my 2005 yesterday and the bike seems to be surging and slight backfiring while riding. The carbs are bone stock with supertrapps & K&N filter. I plan to do the shotgun today since its been awhile, but not sure if thats going to help any. When running the bike opened up, it has plenty of power as usual, but on lower throttle it seems to be surging at a steady rpm.

Any ideas?

 

[44boyd]

Mine does that, tore the carbs out and the jets in the fuel bowl were really gunked up. Probably suggest the peashooter too so you might avoid tearing em out. Did you adjust the a/f screws when you put the traps on?

 

[vmax2extreme]

I really doubt im gunked up since I regularly use additives to keep them clean. I figured a good cleaning is the route to go so shotgun first with some seafoam additive and go from there today....

Yes, I have adjusted the a/f screws. I am going to re-sync the carbs too once this is fixed.

Thanks!

 

[SpecOps13]

I'm having troubles with my 94 right now. 2 carbs are FU. Tried the Shotgun but the O-Rings on the A/F Screws are swollen and I haven't been able to get them out. Looking for something that'll grab the screws hard so I can get them out... I think you're headed in the right direction. I may have to pull the carbs apart and swap the Low Jets to 1 size over.

 

[naughtyG]

A good sync is always the first thing to try - it's so quick and easy and makes such a big difference.
Surging at constant rpm (esp. mid throttle) is often a slightly lean condition that's usually fixed by shimming the needles a small amount using washers.
But a shotgun/peashooter may help as well if any of your smaller passages are clogged, so defo do that too and see how it goes.

 

[vmax2extreme]

A good sync is always the first thing to try - it's so quick and easy and makes such a big difference.
Surging at constant rpm (esp. mid throttle) is often a slightly lean condition that's usually fixed by shimming the needles a small amount using washers.
But a shotgun/peashooter may help as well if any of your smaller passages are clogged, so defo do that too and see how it goes.

I plan to break into the carbs later today. Rode her to work this morning and shes surging at mid range for sure. I really doubt I am lean since I have the stock setup with supertrapps wide open. I should be rich. I'll pull plugs later too just to check.

Thanks,

Mike

 

[naughtyG]

Agreed, it's most probable it's rich over the whole range, but you could still have a lean condition just at half throttle because of the transition from one part of the carbs to another. that's why the needle shimming often helps - it just allows a little more juice at that part-open throttle setting mostly used for cruising.

 

[sdt354]

I'm having troubles with my 94 right now. 2 carbs are FU. Tried the Shotgun but the O-Rings on the A/F Screws are swollen and I haven't been able to get them out. Looking for something that'll grab the screws hard so I can get them out... I think you're headed in the right direction. I may have to pull the carbs apart and swap the Low Jets to 1 size over.

Have you tried air pressure yet Dave? You should be able to back them out, then shoot an air blast through PAJ1 and catch them in a rag.
Steve

 

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I was out riding my 2005 yesterday and the bike seems to be surging and slight backfiring while riding. The carbs are bone stock with supertrapps & K&N filter. I plan to do the shotgun today since its been awhile, but not sure if thats going to help any. When running the bike opened up, it has plenty of power as usual, but on lower throttle it seems to be surging at a steady rpm.

Any ideas?

I had a similar issue awhile back. It happened in the middle of a ride. The symptoms only occured in the midrange. If i opened it up, it ran fine, just cruising, it was jacked. I went home, tore the carbs apart and didn't see anything out of the ordinary. Put it back together and it still ran like crap. I put some seafoam in and hit the road. Went till the low fuel light came on. Filled it up and added a few oz of seafoam again. After that, no more problems.

 

[vmax2extreme]

I had a similar issue awhile back. It happened in the middle of a ride. The symptoms only occured in the midrange. If i opened it up, it ran fine, just cruising, it was jacked. I went home, tore the carbs apart and didn't see anything out of the ordinary. Put it back together and it still ran like crap. I put some seafoam in and hit the road. Went till the low fuel light came on. Filled it up and added a few oz of seafoam again. After that, no more problems.

I performed the shotgun and peashooter routine on my carbs and carefully placed the stock airbox back on. Going to clean my K&N filter today and figure out how to service my motion pro carb sync since I had to get new fluid for the tool. Oh, I changed the oil and filter too! I test rode the bike and it did seem to still have the midrange issue at first, but then it went away. I need to really get the bike out on the open road and just open her up good. Going to do another tank of seafoam again too.

 

[vmax2extreme]

Today I cleaned up my K&N filter and re-oiled it. Sync'd my carbs which weren't too bad to begin with. Took her for a 30 minute spin and its like night and day. Strong again!!!!

Happy camper here now....