Ok, I'm so sick of this carb problem already! My bike is running so poorly, I don't want to take it out and I hate that! Here's the lowdown... I just put the bike on the road a couple weeks ago, the same time I changed the exhaust from stock headers w/Samson slip-ons to Roadhouse Dooley's. On the fuel that had been in the tank all winter, the bike ran great, just like she always has. After I filled her up, nothing but garbage! The bike feels absolutely horrible!

I know I likely need some rejetting due to the exhaust change, but it was just so odd that it only started to misbehave with new fuel. The bike is coughing and sputtering, as if it's starting to run out of gas around 1/4 throttle. I've been able to establish through people here that I'm too lean. Here are my details:

Air intake: Hypercharger w/stinger trap door
Needle Manufacturer: DynoJet
Needle Clip: 4
Jet Manufacturer: Mikuni
Main Jet Size: 170
Pilot Jet Size: 35
PMS Screw Manufacturer: Stock
PMS Turns Out: 3.5
My Elevation (ft): 32

I was previously at 3 turns on the PMS but changed it to 3.5 before the ride home to see if that would help. Well, it seems like it that helped on acceleration from a dead stop, but I still have the coughing at cruising. I believe the main is fine, I don't have any complaints when I open the throttle up.

Riding back home, I started to notice a lot more popping on high rev decel too. I really just want to get this setup so it's riding proper. I'm not super mechanical, but I have to get this figured out. I don't want to leave her in the garage all summer. I'm feeling pretty bummed right now...

It is frustrating when our bikes run poorly but keep the faith. A lot of good carb guys are on the clinic and will come to your aid. Just a thought, you mentioned it ran great on the gas you had in the tank but started to run poorly after you filled up with fresh gas. You may have gotten some gas with water in it. Put about 6 ozs of Seafoam in the tank and see if it helps before you go for the carb. You may indeed need to rejet but try the simple stuff first. You may get lucky.

You may also have a batch of bad gas.

If the bike was running fine on the previous fuel and the only change was filling up the tank I'd drain the tank into a gas can and get some gas from another source and see how she runs. If this cures your problem then you know it was the fuel. If it doesn't then you know to look elsewhere. I would try this before I started tearing into the carb.

My theory has always been try the simple things first.

-M7

Good chance the new gas loosen up all the lacquer build-up from sitting so long, or from sediment that was at bottom of tank and new gas swirled it, and now your jets are clogged. Your settings are close enough to not cause major issues or to re-jet for the pipes. Highly suggest to do a good carb cleaning off the bike.

You are not lean!!! If anything you are slightly rich on the needle set-up and the pilot screw. You managed to get crap in the carb blocking flow of gas. Again, highly suggest before you start any jet changes, do a good cleaning to the carb, or remove the carb and take it to a shop and have them do a cleaning.

I agree with Erb - If your bike sat for a while I would go ahead and do a thorough check and cleaning off all fuel related items...fuel filter, petcock filter, carb inlet filter, and a real good carb cleaning. I would also check that new exhaust for leaks. From what I hear the duals can be a little tricky to get everything sealed.

Mark7 wrote:
You may also have a batch of bad gas.

If the bike was running fine on the previous fuel and the only change was filling up the tank I'd drain the tank into a gas can and get some gas from another source and see how she runs. If this cures your problem then you know it was the fuel. If it doesn't then you know to look elsewhere. I would try this before I started tearing into the carb.

My theory has always been try the simple things first.

-M7

+1

Did you do anything with the spark plugs and the wires?? I had some problems similar and my plugs ends were loose. I unscrewd the ends off the wires, cut about 3/16th of an inch off then screwed the plugs back on. That cleaned it up about 99 percent. If there's anything that scares me it's the carb. . .I don't ever want to go in there. . .

Hi Mark,1st of all dont fret,this isnt a big deal at all and is very likely a fuel and or debires/dirt issue in carb like the other people told you not requring your bike be laid up all summer or anything like that so dont worry.

We will help you get it corrected but it may take some patience and trial/error on your part untill you get it fixed trying the things we suggest.

BTW,more poping on decel from higher rpms could be caused by dirt in pilot jet & or piot circut or decel enrichening circut leaning it out too much on decel which makes sence for what we think is happening here with poss bad fuel gumming up carb or bad load of new fuel gumming up the carb.

Before you bother pulling carb appart for what may be some debires that loosened up due to fuel not being stilized durring winter thats gone slightly bad and or if you got a bad load of fuel but i'd 1st try a healthly dose of seafoam @ 1.5oz per gal before ding anything.

I have recently hit some problems with fuel going bad in a few vehicles i was working on and just for ha ha's i 1st tried a health dose of seafoam in both cases and it did the trick,didnt have to pull carb appart or in othe case do anything with the EFI .

So if you decide to try this use a minimum of 1.5 oz seafoam per gallon and then take the bike for a ride to get the treated fuel into the carb and if it's running good enough that its not dying on you or unsafe keep riding it to get some miles with the seafoam but stay close to home just in case it dies.

Then after doing some riding with seafoam in fuel system if that hasnt cleared things up yet let the bike sit overnight with the seafoam treated fuel soaking in carb/jets etc to loosen up/clean out the jets (esp pilot jet) which is what i had to do in 1 case.

Then fire it up and take it for a ride the next day to see if its cleared up yet.

If yes great but if not then you either still have dirt etc in carb and or you possibly got such a bad load of fuel it was too much for the seafoam to handle.

On 2nd thought you could drain(syphon)current suspect fuel out of bike 1st,get new fuel from another source & refill bike feul tank while also treating it with a min of 1.5oz seafoam per gal. Then fire up the bike for a ride to see if the seafoam will do the trick or not weather it be while riding and or having to let bike site overnight with treated fuel soaking in carb to see if that gets it when you fire it up the next day.

But keep in mind all this is assuming your having some sort of bad fuel and or dirty carb issues which is likely the case here becasue as already stated jetting is plenty good enough for your setup as is and should be acting that lean esp since it was running ok prior .

If its a dirt/bad fuelsituation the seafoam seams to have the abilty to loosen it up enough and or break it down enough to pass thru small jets/carb circuts etc avoding hading to dissassemble the carb which is a great thing,stuff can work wonders at times.

1 last thought,if your mehcnaically inclined enough to try this out if seafoam treatment doesn't get it try this which has also worked for me in the past in this type carb situation.

But again,dont try this if you dont feel completely comfortable doing what i suggest,i have almost 40yrs exp with stuff so it not an issue for me but i realize it could be an issue for a less experienced person .

Fire up the bike to warm it up & then remove the air claenr assembly.

Then fire up the motor and rev it to approx 3k-3500rpm and then quickly let commpletely off the throttle which at the same time completely covering the carb throat for 1-2 seconds tops as motor is commong down from the higher rpms.

But you must remove your have in time enough /with enough rpm left to reopen the throttle wide open clearing it back out and refiring .

What doing this does is create a very high vacuum situation in the carb when to choke it off aqt higher rpm with throttle retunred to idle postion with palm of you hand which can sometimes suck dirt etc right out ofthe ilde and or pilot circut in the carb allowing you to avoid diaassembling the carb.

I generally do that rev up and choke off carb throat process at least 2-3x in a row before letting motor idle back down to see if it has worked,but in your case you may b=need to ride bike to see if its fixed.

And if motor stalls while doing this its loaded up so hold throttle at least 2/3 if not wide open when refiring post stalling when trying this high vacuum suck out deal which has worked for me at times over the yrs.

If doing the above doesnt get then its time to remove the carb for a complete disassembly /cleaning/reassembly & readj of flat lvl etc and reinstall which should get it cprrected at that point. But make sure to use compressed air and or small wire in small holes in jets and carb to ensure you get all holes/circuts properly cleaned out because if you miss anything it can still cause the bike to run poorly.

Good luck.

Scott

Thanks so much for everyone's responses! You guys are truly great! I am going to give the Seafoam a try, as it's the least intrusive and potentially, the simplest fix. I wasn't sure if I could find it being that I'm up in Canada, but there's a automotive shop only a few mins from where I work that stocks it. Here's crossing my fingers that it could be that simple! If not, I'm already feeling better about tackling the carb for cleaning.

Here is something we should all know how to do. Every spring, remove the line from the petcock and drain about 4 or 5 ounces of fuel from the tank into a clear mason jar. Swirl it (like a glass of wine) and at the bottom of the glass, look for bubles, it's a sign of water in the gas. Water will settle to the bottom of the tank. So if you do have water, keep draining it (throw the old gas into a can for your lawn mower or something) and keep draining and checking it until you either run out of gas, or it's clear for 2 samples in a row.