Triumphrat

slate_206 · 04-20-2007, 12:51 PM

I have a new '07 T100, which I LOVE. The only issue is that I've found that it's very hard to start in the morning and even when it's been sitting for a bit during the day. I think that the choke might need to be adjusted a bit but I'm not sure. Any ideas? Also how would I go about adjusting the choke?

Thanks so much in advance!

lindsayt · 04-20-2007, 01:18 PM

IMO, these bikes are insanely lean from the factory, and so require an awful lot of choke to start. I live in Minnesota - in the winter, when it's 10 degrees (F) out, I have to leave the thing on choke for like 10-15 minutes to warm up before I ride, or I'm riding ten miles with some degree of choke. Even right now, when we're getting daytime highs of 65 but morning temps of 45-50, I'm finding I have to let it warm up for like five minutes in the morning, and a minute or so (with choke) in the afternoon.

I'm sure it's for emissions reasons. I'm kind of considering going up a little on the main jets just so it'll start a little easier and warm up faster. I come from a 2-stroke scooter background, where the first thing you do is yank those lean factory jets for fatter jets to get a juicier mix. In the 2-stroke world, it's not just about easier starts - it's also about better cooling. I guess on these you don't really have to worry about the lean mix making for ineffective cooling, but I'd still like it a little juicier.

Anyway, I think you're experiencing the "normal" behavior for these bikes from the factory. Other opinions?

Geoff · 04-20-2007, 02:04 PM

my opinion is that going with larger jets will do nothing for cold starts. its not on the jet till 3/4 throttle.
What you need is to adjust the idle mixture richer, or go up 1 size to a 42 pilot, from a 40 stock
G

lindsayt · 04-20-2007, 04:46 PM

Good point Geoff.

slate_206 · 04-20-2007, 06:05 PM

Looks like I'll need to adjust the idle mixture.

thanks!

A2WheelCpl · 04-20-2007, 07:24 PM

I have the exact same problem, now I know it's because of EPA and leanness, but when you drop that amount of money on a brand new bike, and you can't get it started teh first day, it does make you a bit mad!!!!!.. I agree with the carb adjustments, my thruxton has had the jets and pilots changed and it starts very easy. I was also told that if you take off the AI, it will help with cold starting as well. I don't have any way to judge that because the Thrux had it all done at once.

badrufus · 04-20-2007, 09:45 PM

Try adjusting the idle mix screws before you go up on the pilot jets. I have an 05 T100 with 40 pilots and have no starting problems, cold temp, warm temp, ridden, not ridden. Don't give the bike any throttle. Just give it choke (for me, half choke if above 80F), turn the key, and hit the starter.

ohiorider · 04-20-2007, 09:56 PM

I'm not sure it's just an EPA thing. I owned and rode a W650 for 7 years and 52,000 miles, and just sold it a few weeks ago. The W came with dual Keihin carbs, perhaps a mm or 2 smaller than ours, but the same type of CV carb.

The W would start (and this is without rejetting, etc) in the dead of winter with minimal effort. Granted, it was tuned quite lean, and required running on choke in 35-40 degree weather for a few minutes, but it was never difficult to start, and took no more than a couple of seconds with the starter to get her going.

Unlike my T100, it was possible to give the bike some throttle when starting cold under choke, which is nearly impossible on the T100.

I asked an old BMW mechanic why bikes with nearly identical carburetor systems acted so differently when cold starting. He commented that perhaps Triumph asked Keihin to modify the size and location of a couple of the small openings (drillings) into the venturi area, to meet their requirements. I have no idea if this is a possibility. All I can do is report on how two vertical twin bikes with nearly identical carburation systems cold-started quite differently.

Regards - Bob