Bonneville America Forums Forums Technical Forums General Tech i think i may have an idea as to whats causing it

take off and in 2nd go to about 15 then let off the throttle and decellerate. from that point to 15 MPH you should (if you had this problem) feel a jerking like vibratiion thru the footpegs that CANNOT be mistaken. In other words, if you THINK you feel something, you ain't feeling it !

I'll try it....

Phil,
Ya gotta believe me when I tell ya, this is not something you can recreate unless you find the source of the problem. As Dale says, there is no mistaking it.... it's there or it isn't and I can tell ya it's not supposed to be there. Mine has gotten to the point that it does it now just sitting at a stoplight idling. Feels like you are driving over rumble strips. I was still thinking it just HAD to be something with the wheels since it wasn't happening before the new tires and especially since Dale said he had new tires installed as well. I even made an appointment to take it back and have the wheels/tires checked out... sitting at idle at a light this morning and feeling it, well cancelled the appointment as there is no way it's coming from the wheels.... it's IN the engine somewhere, somehow. Gonna have to take it out to the Triumph dealer now and see what they have to say.
Pulled the plugs today, not the picture of perfection, a little bit black but not awful. B!tch of it is that I am one month out of warranty so I wanna see what the results are with Dale's new coils before I just had the bike over to the dealer and have to start throwing down for diagnostics and "maybe" fixes.


Steve

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really ! Is it cyclic even at a standstill?

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Yup.... if your new coils solve the prob then I'm sending you a bottle of your favorite spirits as a big thank you. I'm hoping they do but I gotta tell ya, as of right now my money is on something in the clutch/transmission.
For the rest of you that may be following along on all this, bear with me/us, nobody wants something else to obsess over more than me.

Steve

If it does work it's still not time to send the beer. Could be 2 different problems here that both manifest the same symptom. The reason i ask that is mine isn't doing anything abnormal at a stoplight. So i'd hate to see you buy new coils only to find it worked for me but not you.
The clutch or tranny just seems so unlikely. Not because they wouldn't cause this sort of symptom. In fact they probably would more likely than most anything. But with 9k miles on a bike thats been treated very well with new oil more often than it needs, and the best oil at that, it just doesn't seem theres any reason for that. Sure, it could be a defective part i spose. Just doesn't seem likely.

Anyone checked their clutch?

Not really. Just the adjustment. This would be one of the last things i'd do because i'd have to dump the oil and remove a side cover. So if all else fails, maybe. I think that the fact i can recreate it with clutch in or out probably eliminates it as a suspect tho.

OK yous guys, ensure that your crankcase vent is unobstructed too.

If I recall from the Nor'East rally, Steve's ride has a jingle sound while at idle. I bet if you guys pull your left engine cover you will see something amiss. The early clutches had an issue with vibration and such. A factory fix has been conjured up and Pat can speak to the details of why the older clutchs are somewhat out of touch with fluid dynamics.

Another member had to replace his oil pump gears. Have a look see at those gear's teeth too. (while you have the left cover off).

Dazco, Pay no attention to that sparkplug behind the curtain! He is an old spark! hahahhahahahah Hey newt? Can you dig it brother?

I may be wrong, but i've read about that and i thought the clutch issues were remedied before 05' which is what mine is. Steve's is older tho i think.....seems like he said it's an 03 at some point.

I thought of the clutch because someone said theirs changed with the clutch in. It may still happen, but the act that it changes with clutch engagement would point me in that direction. With the time you've spent on this so far, what's a half hour of oil-drain time?

Daz, Jefferson may have a point there. I wasn't aware that that you had an aftermarket air cleaner(K&N or UNI'S). If you do then clean it and LIGHTLY!!!!!!! oil it then see if you plugs are fouling.........Angelis

No, the filter is clean. I cleaned it after that happened and i oil it VERY lightly and always have. And i've been doing it that way since i got it.
Benny...i may have said that when i first started posting. But if you read all my posts in both (maybe 3?) threads you'll see i have updated what i've said on a few things as i've investigated deeper. I've since found, and i think i mentioned it in this thread just withing a day or 3, that i can recreate it in a number of ways with clutch out, clutch in, or even in neutural. I posted this in this thread just yesterday....

"One thing i noticed thats VERY wierd. I can go down a hill so i can coast at a steady speed, the speed range the vibes happen at when the engine is engaged. Then either pull the clutch or put it in neutural and rev the engine and hold it at a steady 2k RPM's or so WHILE in neutural, i get the same cyclic vibration ! And this is with the engine disengaged. But the really wierd part is that if i do the same thing at over 25, it doesn't happen ! tell me that ain't bizarre ! The only thing i can figure is somehow at the rpm and speed the engine's cyclic vibe is there and tires/wheels are interacting harmonically when things line up just right to create it. Sounds freakin wierd but it does it none the less and i can't figure out any other way to explain it."

by the way, the coils and wires are due tomorrow so hopefully i'll be posting some good news. The way things are going tho i have no delusions that i'll be doing so for sure.

Oh I'll happily admit to not reading every single post

I'm just saying that as long as the motor is running, part of the clutch is spinning...

Nologys and wires in, no change.

I think i may have figured out why it's rich. I pretty much finalized the jetting last winter, having bought the bike that summer. I jetted it by going larger till it was too rich then backing down a size. So it was on the edge of being rich. The plugs always looked good but It wasn't till this heat wave that i noticed the plugs getting sooty. My theory is based on what i've been told here before, which nis that in cold wether your bike runs leaner, hot, richer. So it would make sense that the very hot weather we've had put it over the edge and made it too rich. Coulda sworn i had 1 shim on the TBS needles, but i just went to check the slides and remove the shim and realized i had 2 shims. So i removed them all. The bike seems to run about the same,so i'll leave it there and see how it does. I think it'll be fine because the midrange is where i do most of my riding and thats where it was jetted very rich.

as to the vibes, i have yet to really give the front end a good going over. And as i said before i had a problem getting out one of the axl clamp bolts and had to really bang on the fork with an ez out. So i'll take the front end completely apart tomorrow and inspect the bearings and everything then put it back together. Could be the forks just have to be reset. The fact that i can recreate the cyclic vibration while coasting and then holding the revs at about 2 k, but it won't do it coasting at any speed higher than about 25 tells me it could well be a harmonic between the wheel and the engine at 2k RPMs. Or the rear, tho i've removed and checked that so many times i doubt it.