Tricky problem, need some help

[dazco]

Hi,

I hope you all will accept my question even tho i don't own a Suzuki. It's a newer triumph cruiser called a speedmaster. The reason i'm asking here is that it's a tough problem and i've exausted all my options as far as triumph forums with no success. And since it's a rather generic problem anyways, i was hoping someone here could help me. I'm getting desperate at this point.

It started after i removed my wheels and brought them in to have new tires mounted. I got the same tires as stock........metzlers. I didn't notice the problem till about 20 miles after the first ride with the new tires, so i can't say it was a coincidence or if it DID start due to something having to do with the tire swap or if it actually started 20 miles later due to something unrelated.
What happens is i get a cyclic vibration thru the footpegs, but i either don't get it anywhere else but the pegs or it's very hard to feel. It only happens in 2nd gear (far as i can tell unless it's there but too little to feel easily) and only between 15 and 25 MPH, and if i pull the clutch it goes away. At any other speed/gear i cannot feel it. there IS a possibility i get a regular constant vibration elsewhere thats just slightly more than before, but if so i can't be sure. Just seems like it MIGHT. But if it does it's barely any different than before which is why i can't be sure. But the vibes i feel in 2nd between 15 and 25 is very obvious and as i said cyclic as tho the chain has a big varience in tight and loose spots. But i then got a new chain and sprockets and it hasn't changed at all.By the way, wheels are alloy, bike is a 900cc parallel twin thats a sort of updated version of a classic triumph.

here are the things i've done so far, some unrelated to wheels and final drive but it could be anything related or not, sooo......

1-new chain/sprockets
2-checked tires and wheels for trueness (more later)
3-checked cush drive......fine
4-checked all 3 rear wheel bearings.....fine
5-checked brake........fine
6-tried various alignment and chain adjustments........fine
7-checked final drive bearing at front sprocket........fine
8-checked rear shocks and tried different adjustments........fine
9-checked to make sure all spacers etc were right on rear wheel...fine
10-checked axl for straightness
11-checked motor mounts and many other bolts for correct torque.....fine
12-balanced carbs, removed and inspected pilots, checked float level, tried various mixture screw settings.....fine
13-inspected EVLS (Ca model) and even capped it off and no change after test ride
14-cleaned UNI filter
15-new plugs
16-checked oil (only 2k on change)
17-checked for vaccum leaks

I've i've done more but after all that i can't recall accuratly. At this point i feel it's either the engine, tho it runs perfect other than that vibration, or the front end. As i said above,"more later about the wheels" There is a very slight flat spot on the edge of the front rim. I thought the shop might have done it while changing the tires. But i have since talked to a boatload of people, some from tire companies and shops and a number of people online have all told me there is no possible way that could happen when mounting a tire w/o damaging the rim visually and that it's very unlikely or impossible in any case. they all said a pothole is the likely culptrit, and i did hit a huge one not too long ago. So i don't think thats it. But a shop did say that a new tire could possibly cause symtoms to show when the old one didn't because it was on the bike when it happened. However, again, when i pull the clutch it goes away which doesn't sound like a tire or wheel. Plus i've been told many times that wouldn't be the cause with the symptoms, especially due to the fact pulling the clucth makes it go away.

Any thoughts you have would be greatly appriciated. I don't know what to do next other than try and see if theres anything in the front end i could have done. Tho again, with the clutch pulled it goes away, so i don't see how it could be related to the problem. And yes, i have thought about tranny damage to 2nd gear, but i think it's probably not that but more a matter of that gear/speed/RPM just happening to be where it's resonance is. Plus i keep the oil changed and don't drive it hard. I baby it pretty much. Please.........any thoughts you have may help, and even if you have an idea on someone or some place that may help me. (L.A. area) The dealer is out for many reasons i don't wanna go into. but suffice it to say it's not worth mentioning. Thanks

[dragbar]

How many miles does she have on her? 1st tire change?

[intimid8er]

Nice bike! Speedmaster fan here!

I'm scratching my head on this one........pulling the clutch in makes it go away.......I'd have to say that it's not related to a tire swap.

[dazco]

Originally Posted by dragbar

How many miles does she have on her? 1st tire change?

Yes, first change to the same tires as stock, and 9k miles.

[dazco]

Originally Posted by intimid8er

Nice bike! Speedmaster fan here!

I'm scratching my head on this one........pulling the clutch in makes it go away.......I'd have to say that it's not related to a tire swap.

Thanks, i love it. Butif i can't figure this out i may be looking for a new one ! Yeah, thats what i've been told about the wheel possibility. But who knows.....this is a tricky one. I now feel like it's likely a engine or frame thing. But the feel of the vibration seems SO much like a drive train thing but with new sprockets and chain and good alignment i've eliminated that as much as possible unless i'm missing something. A lean low speed fuel condition is said to do this, but i've balanced it and checked for clogged pilots and float adjustment and mixture screws with no luck.

[Danr]

My Guess is it's a tire, yeah I know it goes away when pull in the clutch, but a few laws of physics come into play when you in effect remove driven force to an object (the bike). Now that I have confused myself and a few others, I would swap out the tires, sounds like one is out of round ever so slightly. Are you sure that what you are feeling is real or perceived ?

[hammersfan]

I would live with it till next tire change, after all it is only in 2nd gear between 15-25 mph.I wouldn't want to spend a lot of cash hunting down that problem.

[dazco]

Actually, i think i may found the problem. At least it IS a problem whether related or not. My plugs have recently become completly sooty black. About the same time this problem started. It can't be a fuel problem because i have run the same jetting for a year and theres nothing blocking the airway before the carbs, and both plugs being sooty it can't be a carb problem or only one would be sooty. And the UNI filter has been cleaned. Then A guy at a triumph forum told me he too had a problem with sooty black plugs and it was his coils. So i ohmed them out and sure enough both secondarys are completly open ! So i gotta assume this problem is related to the vibes. Then amazingly another guy posted saying he's been following my thread and he has the exact same problem........vibes thru the pegs in 2nd gear only between 15-25 MPH ! Heres where it gets spooky.......it happened to him right after a tire swap ! So that speaks to the probablility it is a tire thing and that the coil thing is a coincidence. however, he said he's going to check his plugs and get back to me. If they turn out to be sotty that would mean that almost has to be the source of the vibes and that the fact we both had the problem after a tire swap is a one in a billion coincidence. we shall soon see. In any case, related or not i need to get this fixed under warranty. Bizzare, eh?

[intimid8er]

Originally Posted by Danr

My Guess is it's a tire, yeah I know it goes away when pull in the clutch, but a few laws of physics come into play when you in effect remove driven force to an object (the bike). Now that I have confused myself and a few others, I would swap out the tires, sounds like one is out of round ever so slightly. Are you sure that what you are feeling is real or perceived ?

<Scratching head>

I guess next you're gonna tell me I turn my bike at speed by pushing on the handlebars!!?????