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Hi all, have a '99 trophy 1200 with a very annoying problem. It judders and jumps (misses) all the time! Have changed plugs etc but no difference. The REALLY annoying thing is that if I remove the tank (to check plugs etc) it runs fine for about 10 miles then starts the old problem again. By chance, I tried using choke while it was doing it, and it stopped the problem! but of course I dont want to run with choke on all time (also does little for the idle speed!). Please help, my mechanical knowledge starts at a clothes peg and ends at a mouse trap, what is it, and why does the choke solve the problem? many thanks in advance. Dave.

check the vent in the gas tank.go for a ride with the gas cap off if it runs ok it is the vent.

No! Send it to me before chucking it in the canal.

Anyways, if you look throught the threads here, you'll see that I recently picked up the same bike with similar problems. As silly as it may be, I'm trying to post here the progression of my work on it. Perhaps it will help you. Just recently got it into a Triumph mechanic. Balanced the carbs and I'm going to pu some more miles on it (I average 400-500/week) before I noodle with it some more.

Continued problems seem to point to ignition coils according to my mechanic friend who had similar problems with his 1999 1200 Daytona. They're expensive, though. So I'm going to look for a deal on ebay. Once we can determine if they're the problem and I can locate some, they're REAL easy to replace.

Of course, if you read through the threads and have any questions, I'll be glad to tell you what I know. By the way, where are you?

hi, thanks for that. Had a nagging doubt about the coils, just couldnt understand why the choke was curing it. Just had the tank off, checked fuel filter on petcock, clear, checked vent from tank and likewise, clear. All lines been check for kinks and cracks and they are all ok. It has, as usual started up beautifully as it always does once I have had it to bits, but i can guarantee it will be back to square one on the way to work tomorrow! I live in North Yorkshire in UK, it is used daily, doing about 40-50 miles a day Its been a bit of a lemon from day one, took it in for new brake pads and ended up with a bill for £832!! new discs, callipers etc and now it has a leaking oil cooler, and the forks are now leaking! Think someone has voodoo hexed it! Just want to get it back running ok so I can trade it in on a Goldwing, wish Id bought one last time instead of this thing, the price on parts is daylight robbery. Its the third Ttriumph I have had and each time I keep saying it will be the last, more fool me!

You're in the UK?!?!? Just go to Hinkley and kick thier arse.

The coil thing is really tough to diagnose since it seems contrary to everything. It seems to get worse as it gets colder. Normally coils have problems as they get hot. Anyway, this friend of mine bought a pair on ebay and that cleared a lot of stuff up. They're $126 US apiece here. I don't want to do that until I'm sure other possibilities have been eliminated.

We both have experienced the choke thing also. We went through carb rebalancing on mine and it's helped a lot (but still not quite there). Apparently, these are running pretty lean, State-side anyways, to keep CO down. They can be a bit twitchy. Choke seems to richen it just enough to smooth it out sometimes.

I'm noodling with the idle speed a little bit right now and sometimes it helps. While doing the carbs I learned that on my bike, normal idle speed of about 1000 rpm on an analyzer works out to about 750 rpm on the tach. I gets worse as I try to raise it.

Of course, we're both Brit bike nutcases (just trying to help your economy). Keep me posted.

Went to Hinkley with arse kicking boots on and was faced with a sign on the door saying "closed due to lack of interest, come back Tuesday if it aint raining". Have also tried standing in front of bike clutching a bottle of paint thinners and wearing a menacing look, it merely giggled at me...
Thanks for the info and would really appreciate any updates, we have been promised 7 minutes of sun in the next few months, would be a shame not to be out riding in it.