Bonneville America Forums Forums Technical Forums General Tech sputtering, missing, or something

OK, here's my dummy question of the week. I have noticed a missing/sputtering kind of thing the last couple of times I rode the bike.

It occurs really bad when the engine is cold. I let it warm up on choke while I put on the gear for the ride and this used to be enough. Now I can hear the sputtering for a mile or so and it feels like it just isn't getting power. After it runs it gets better but there still seems to be a flatness and the response isn't that same get up and go.

I got rid of the AI yesterday but it still has the problem. While I had the tank off I replaced the plugs with the irridium ones. The old plugs were tan on the white insulator part. I gooped everything good with dielectric grease, unplugging and replugging almost everything under there.

I have not done anything to the carbs, no adjusting or anything. Everything is still factory set.

I thought of water in the gas, but wouldn't this be the same problem when hot as when cold? Or could it be that running the bike throws the water into suspension and lessens the symptoms?

Here's a few ideas...

Had the tank off? Is the vent line pinched? When the problem occurs open the gas cap and if you here a "whooosh", well, there ya go.

Are the carb rubbers seated correctly, pliable, and the clamps tightened securely?

Are the little squirrel condoms on the 4 vacuum ports on the intake in good shape and stuck on there securely?

And finally, on a post about dialectric grease a short time ago, someone mentioned to use it sparingly, if at all, on the high voltage connections, i.e. coils and plugs. Maybe you over-gooped those....... a "film" should be sufficient on those....

I'm sure there will be other opinions coming any time now, so stay tuned.....

How 'bout checking the air filter? When was the last time it was changed? Is the airbox clear - some bikes have had mice nesting in there (DON'T ask how I know )

Jan

Might have a ignition coil going out check for good spark
that happened to me not to long ago make sure exhaust is hot out both pipes before you ride or check voltage at coils then check spark. Or air could be getting in on rubber boots betweencarb and intake I recently had same troubles.Are you backfiring too?

I don't think it was the breather hose since this is the first time I had the tank off. She has 11K miles without trouble until just recently, which got me off my lazy butt to do something. (if it ain't broke...)

The rubber tubes hooking the carbs to the airbox look OK. I haven't pulled them yet so all is still factory tight. (Factory set DOES say something, doesn't it? Hmmm...)

The airbox has a good crack in it from a backfire when starting. (That will get you noticed in a crowd!) The air filter hasn't been changed but it looks good, only crud on the lower part of it. (I stopped buying stuff when I gave Santa my list, and the filter was on there.)

I don't have the tools to check the coils for amount of spark, but both pipes get evenly hot. I was checking for one side to be missing while it was still on the jack and tied down securely. Don't do that if the straps are on the forks so they are out of the way -- I now have shorter straps and gunk to clean off the pipes. BTW, they melted through within seconds of each other, so both cylinders are firing about the same.

I had lots of backfiring in the silencers before this AI removal. Now it is down to almost nothing. And to think I waited all these miles to do something about it. You guys have been telling me but I was just too lazy and wanted to play with the bike instead of work on it.

I'm going to pull the tank and dump everything out of it today. Hopefully it will be the simple thing this time. I hadn't thought of water and the mixing of the it into the gas until I was typing the initial post.

Guess I'll clean up some of the dielectric grease while I'm there. (If a little does a little good, then a lot...aw, forget it.)

Gary,
If you're going to empty the tank you might as well clean the petcock screen at the same time. If you got some dirty gas it could be clogging your screen. You may also want to check the hidden fuel filter.

Good Luck

I got my "bear paws with mittens on" hands dirty and did the tank draining. Good clean gas.

Carb bowls had some fine metalic dust and some black flakes. No water. The hidden filter was OK, a couple specks.

I have a couple of jets and carb screws and pretty hose clamps from Brent, what the hay. I get the print-out of Pat's instructions (I can't thank you enough, carbs for dummies) and tackle the job.

I decided to leave the pilot jets alone and move on to the 130 mains (it had 125 from the TSOR's, but I had them sitting around waiting for the air change). I put my 8mm on the holder and it moves. It was about to fall out, only a few threads holding it in there. You can bet the dealer will hear about this one since the jets were changed with the TSOR's.

The bike is back together except for the seat. I popped the top snorkle out. I don't get the inside snorkles, couldn't feel anything in there that felt like it could come out, just hard plastic. The airbox was cracked worse than I thought so now it is sealed with silicon to keep dirt out. I'm letting that set overnight, then the big test tomorrow morning.

My neighbor keeps ragging on me about fuel injection and mapping and all that stuff, says I need to get with the times. Walking out of the kitchen into the garage there it sits, stripped down for the carbs. Just a bike, clean and simple. Silhouetted against the outdoor sun. That's a darn purdy sight.

I either didn't read about this filter or forgot it. Blame it on age. I'm hoping the loose jet holder was the problem and it is fixed now.

I hope your problems get solved and santa gives you all the goodies you wish for. tell your neighbor he can spend his money on fuel injection (problems) and repairs while you save money for aftermarket goodies. merry christmas

I had to test it out about 10:00, couldn't wait 24 hours for the silicon to cure or even 'til morning. It started up better than I ever remember, pushed the choke in within seconds instead of the usual minute or two. Idles nice and smooth. Took it out for a run and it is awesome.

I can take off from a stop like I mean it. I can pass cars without dropping a gear. I guess it is one of those things where it goes down so slowly you don't notice it until it gets really bad. Seems like a different bike now. So, how do we reset the rev limiter to about 7800?

It may have been the crack in the airbox.... The new jets make a difference, but the hmmmm, "distorted"? air flow may have been part of the problem.
As far as the snorkels going towards the carbs, some bikes have them and some don't. Mine didn't have them either (03 TA).