Triumph Rat Motorcycle Forums banner

1 - 12 of 12 Posts

·
Registered
Joined
·
207 Posts
Discussion Starter #1
So this is a two part question...

So I was in traffic yesterday on Sunset Blvd and all of a sudden my Tiger shot forward and almost rear ended a bus. I hit the clutch and let off the throttle but the engine kept revving as if I had the throttle all the way open. I opened and closed the throttle real quick and it went back to normal. It hasn't done this again since. What should I be looking for as far as why the throttle would stick like that?

Part 2 of my question is...is there a better book than the Haynes manual? Maybe something with more symptom/cause troubleshooting info and decent images? This thing really sucks.

Thanks,
Jon
 

·
Registered
Joined
·
367 Posts
if you have amals maybe are they overtightened on the manifold,they can distort and block the throttle slide up.i had such a distorted carb on my first bonnie and i had to junk it.it was really badly distorted beyond rescue
take of the carb and the cable and try to move it with your finger.it must slip evenly without hard point.GPZ is right too :it can be a sticking cable.
ben
 

·
Registered
Joined
·
1,787 Posts
Almost certainly a stuck slide. Time for a new one, and there are now good chrome plated ones that will be a big help. With the carb off, put a flat edge across the mounting flange of the body. Put a piece of 180 wet/dry sandpaper face up on a plate of glass or thick plexi. Drizzle a little soapy water on it. Gently lap it for a few strokes. If the edges outboard of the holes are bright, then place the body such that those bright spots are on wood blocks and then with another wood block on the bellmouth, smack the carb smartly. Recheck by lapping a few strokes. Repeat until the flange is uniformly bright and therefore flat. I also remove the little web at the top of the flange, I belive this is the hard point where the binding usually occurs. Then fit the new chrome slide with as many new parts as you figure you need. I would recommend the shielded tickler, if you don't have it, viton float needle, new needle, clip, and jet, new gasket and orings, allen screws for the bowl and cap, and extended adjusting screws.
It wouldn't hurt to fit a new cable, too, at this time. If the old one is ok, lube it up and keep it as a spare.
 

·
Registered
Joined
·
207 Posts
Discussion Starter #5
On 2006-12-04 13:18, GrandPaulZ wrote:
I can't see a bike accellerating on it's own

Were you "blipping" the throttle? If so, it was a momentarily stuck cable.
I can't see a bike accelerating on it's own either.

I was in 2nd gear moving real slow in very heavy traffic with a constant throttle and the engine just revved up on it's own. No 'blipping' involved...that would at least provide some kind of explanation.

I had a similar experience when I first bought the bike a few months back when I was stopped at a red light in neutral. The engine just started racing. My mechanic explained it off as a spark plug issue of all things. I never really bought his explanation.
 

·
Registered
Joined
·
1,141 Posts
Call a Priest, a Rabbi, an Imam, and a Voodoo High Priestess!
It's time for a exorcism. Your bike is obviously possessed! :lgh:
 

·
Registered
Joined
·
794 Posts
jonkull,

two possibilities in my mind. One depends on if you are still using the centrifugal advance mechanism

1) binding cable, probably where it's cable tied to the frame, or the bends between twistgrip and around the steering head.

2) What I call "advance runaway". You'll notice when you're adjusting the timing that if you advance the timing, the engine runs a bit faster. If the advance mechanism doesn't spring back into place properly, the timing advances, the revs rise, the timing advances, the revs rise, until it gets to the point where the amount of fuel/air coming in can no longer support extremely advanced and lean running.

If you are running standard points ignition, have a look at the springs in the advance mechanism, and make sure it's all clean, lubed, and coming back to zero advance at idle.
Just my two bobs worth...
 

·
Registered
Joined
·
207 Posts
Discussion Starter #9
Well it's been running fine the last couple days. I'm going to take a look at it over the weekend when I have some time (and light) to play around with it. Thanks everyone.
 

·
Registered
Joined
·
166 Posts
Jonkull... you have great advice from the tech gurus. On the question about the Haynes manual... my advice is: put it on the shelf. I don't know when it was written (away from home right now) and it may be somewhat more accuarate for your '73, but for my T140s... it has been a joke. I was apalled at their version of transmission rebuild info (I rebuilt both my bikes transmissions). And.. the gloomy photos cannot compare with good technical line drawings.

Years ago, around '72, I was present for the photo shoot & tech session for a Clymer manual for the Montesa Capra 125. The little dirt bike shop where I hung around had just got the franchise and the dealer was taking apart a Capra 125 motor for the first time. The so-called "experts" from Clymer were not so much interested in accuracy as in "getting it done"... the whole thing was a sham and we laughed when we saw the finished product some months later... it was a travesty.

I bought the Haynes manual for my Triumphs and when I started to try using it for real nitty gritty information... the memory of my earlier experience all came back... same thing... just something thrown together so a publisher can market it for $19.95.

Best bet is to get the real deal... a factory workshop manual... available from a number of sources. The factory parts manual is also a must.
Britcycle.com has them at a fair price.

The manual is tops for assembly/disassembly...but really, for nitty-gritty trouble shooting... there is no better resource than the guys that frequent this web site.
Best regards,
Dave :cool:
 

·
Registered
Joined
·
207 Posts
Discussion Starter #11
On 2006-12-06 17:35, GulfCoastDave wrote:
Best bet is to get the real deal... a factory workshop manual... available from a number of sources. The factory parts manual is also a must.
Britcycle.com has them at a fair price.

The manual is tops for assembly/disassembly...but really, for nitty-gritty trouble shooting... there is no better resource than the guys that frequent this web site.
Best regards,
Dave :cool:
Dave - thanks for the info. I'm going to try to track down a factory manual. I share your opinion on the Haynes book...I've pretty much given up on it at this point. As for this forum it's one of the friendliest ones I've been on. People are always willing to help no matter how stupid the question is. ;)
 

·
Registered
Joined
·
4,107 Posts
Have you tried a new throttle cable? I had one strand of break on my '70 some years back and it would cause a "hang up" of the carb...sometimes.

Just a thought: Jim
 
1 - 12 of 12 Posts
Top