Triumphrat

doclees

About 2 weeks ago after 30 mile into a gas fill up my 03 Speedy started running a bit rough. After work on the way home it started running like a pig. Didn't think I was going to make it home. Coughing and popping like it had water in the gas. The next day I added some gas dryer. Seemed to make some difference. After adding 2 bottles of gas dryer and 1/2 a bottle of Chevron techroline in 2.5 tanks of gas it still has issue at idle and up to about 2500 - 3000 rpms. After that it runs fine. For about 20 miles when the first tank was at 130 miles it seemed to return to normal. Shortly after fill up it was back.
I have tried running the carb bowls dry and bleeding them dry. No change.
Any trouble shooting flow charts about?
thanks

pz1

might be sucking air, check all the fittings.

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2005 bonnie black, 790cc, sleeper exhaust, airbox cutup,unifilter pods , ai removed, green springs, gaiters, knee pads, mini tach, 157.5 mains,42 pilot jet,1.75 turns, thrux needles,progressive suspension front and back, marine corp emblem.

Drifter

Sounds like the tank is not venting correctly, after a ride open the cap slowly and listen if you here a swoosh sound like air being sucked in the thats probably the problem.

Also like you already did you could have had water in the fuel, if you are running an inline fuel filter check it also maybe a chuck of dirt/paint etc blocking it.

GySchmit

Had the same thing happen to me a few weeks ago. While riding home from work Hamilton started to run like crap... same symptoms as yours.

1 - Changed Gas (though Water in tank) - No water in removed gas (didn't correct problem)
2 - Checked Vent Tube - Clear (didn't correct problem)
3 - Checked Air Filter - Clear (didn't correct problem)
4 - Changed Plugs (left plug fouled) (didn't correct problem)
5 - Drained Carb Bowls (didn't correct problem)

Due to my work schedule I didn't have time to get indepth on trouble shooting so I called my mechanic to come and get him the next morning he pick him up.

2.5 hours later he called and said Hamilton was fine. He pulled the carbs and check the valves/jets which seemed fine. When he reassembled them and fired Hamilton up he ran fine.

We figure one of the valves/jets had had an upstruction in it and when he took them out to clean them it came out (as he didn't see anything).

He kept Hamilton over night and road him around. Haven't had a problem since.

doclees

Thanks all,
I don't see any issue with sucking air but the thought was there. Some cap ends are a bit dry rotted. I'll recheck today. No tank cap vent issue that I can see. No change with open cap. I'm going to try getting to the carbs and blowing some gum cutter into the holes. From what I have read about electrical issues it doesn't fit. Anyone have TPS issues or troubleshooting for this?

I think I will add an inline filter for the future.

Bloggins

A wise man once told me that 90% of fuelling problems are electrical. It might be an idea to check your sparks.

doclees

Pulled the plugs. New iridium. Some fine black carbon deposits. Must assume from this problem. I didn't want to pull all that airbox stuff off to get to the carbs so I opted to run the carbs dry, pull the gas line off the petcock and spray gum cutter into the carbs that way. Made sense. So I ran in on straight gum cutter. Some change but still not right. I'll try some Seafoam tomorrow the same way and in the gas and see unless someone can give me a plausible electrical explanation on intermittent cough, sputter under about 3k rpm and smooth running after about 3k rpm.

doclees

So after reading all the possibilities I thought to go get the inline filter and the tip over valve and start taking it apart. Upon getting to the dealer the mechanic wasn't doing anything and offered to test ride it. Next I know it is up on the lift and he is tinkering. I ask him about the inline filter at the T. He said yes there is one even when my Haynes and Bikebandit doesn't list one. So I give him the go ahead. I even can watch and pick his brain. His first assumption was fuel but upon opening the right carb and blowing it out, seeing good fuel delivery he goes to right spark. Pulled the right plug, fired up the bike and watched the plug fire. To me it looked fine. Then he said it was intermittent which would mean a weak coil. Swap the coil and all is GOOD! Blessings to him and his family. He said this happens more often on the 270 engines and older T-birds.
I guess the coil can build up some capacitance as it sits for a while and then when the rps get high enough. This explains the running ok over 3k rpms. As cheap as I am this was a $220 well spent.