Engine vibration at 70 80 mph !..................... Youtube

[steamer 96]

  I need pointing in the right direction,  out yesterday heading towards Wales and my bike has started make a funny vibration feeling, ticks over normal and rides great 10 20 30 40 50 60.... 70 starts and 80 it feels like a deep rattle within the engine that's not right, pull the clutch in and its smooth, clutch out and it starts again !!   don't know if its the clutch but why does it only start at speed 70-80mph or something like the cam chain tensioner (I thought they self adjust) or anything else. ......   changed the oil and filter on Saturday and replaced the clutch slave as it was dripping !!

     We are going back to Spain on the 10th June and need to get the bike sorted asap,  before I think about taking it to the local butcher to look at and sit I the workshop for a week can anybody point me I the right direction to what tis could be !

         I am on the Wirral (UK) over the water from Liverpool Posh scouse and will be happy to travel anywhere if anybody can recommend somebody who can help as I need to be ready for my Spain blast on the 10th....   I say I am happy to travel anywhere but obviously not if you know some guy called dodgy Peter in Argentina....    that would be silly
   
          any pointers   

           Cheers   
                Steamer 96

[Sin_Tiger]

Try hitting the same speed in 4th or 5th and compare the revs to see if that confirms it's engine related. I think you've more or less ruled out running gear with it clutched although there is still a possibility that there may be something in the chain area, a good look over the chain, sprockets and rubbing blocks.

Does it feel like it's losing power? A check on the fuel filters on the fuel tap is easy to do without taking a load of plastic off, that'll also make sure you have no crap in the bottom of the tank. Get a hold of a can of Profi Fuel Max just in case it's carb related. Does your's still have the little filter in the fuel line between carbs 1 & 2 (you won't know unless you've taken it apart and that's a carb off job)

Coils are a possibility but suggest you try to rule out some other stuff first.

[steamer 96]

  Hi Sin....  My sat nav bracket sits over the rev counter so when I get home I will remove it and compare the revs at 80mph and see if it's reflected at the same revs in 3rd 4th 5th,   Plenty of grunt in the bike and no loss of power, I removed the carbs last month when I changed the air filter and while out and hung to one side I cleaned the little filter between 2-3 and the tap, I gave it a dose of profi late last year and will throw the other half in tonight....

    It was running fine the other week !   Will let you know when I compare the revs

      Thanks for the reply

          M

   

[ssevy]

Because it goes away when you engage the clutch, I would suspect chain/sprocket/rubbing block. The rattling you may be hearing could be chain lash against something underneath the bike. I have seen guys on a bike pass me when I'm in a car, and have noticed the rear chain really bounding around, but only at certain speeds. I suspect the wheel diameter, tire balancing and whatever harmonics are involved affect the chain movement. I would get it on a dyno, where they could stand right next to the bike and listen and see the chain as you rev it to where it happens.

[steamer 96]

   Cheers gents,  it has been raining here bigtime so I havent been able to get out,    when you say "Rubbing block"   I take this is the plastic unit that sits on the side of the swingarm that the chain runs along      www.WorldofTriumph are listing the plastic bit as a "Rubbing strip" for £18.98.....    so along with a slave cylinder seal kit I have orderd the "Rubbing strip" and will put that on when it arrives.   It would have been the last thing I thought of but I will change it anyway so I know its new

     We go on the 10th so time is ticking away and I have booked the bike into a rolling road for Friday afternoon so that will be interesting to see/hear where the noise is coming from.... 

[Mustang]

how is the chain adjustment ?

if you set it like the manual , it's too tight .

you need at the minimum 30-40mm slack especially ridin  double .

the rub strip and rub block are two different pcs.
the rub block goes under the swingarm and takes up the slack from the chain on the bottom run

I'd also be checking the alternator drive vane bolts . they are a common source of rattling in the steamers .

[threepot]

I had a similar problem,but mine was a 'whinning' noise that became more noticeable with speed. Turned out that the front sprocket cover was compacted with a load of crap,oil etc. Cleaned it off,fitted new chain,sprocket,upper and lower rubbing blocks..bike is great now. I was fearing a bearing failure,but thankfully it was just that. Worth a look?

[steamer 96]

   I had the bike run on a rolling road to see if we could hear this vibration and nothing happened  :icon_wink: which was good as I feel confident to take it on our trip on the 10th June, the nice man at the bike shop recorded a bit of the end of the test run and put it onto youtube for me,  he wasn't doing a dyno/tuneup but just wanted to run it and listen however we know its not the same as being on the road.

  http://www.youtube.com/watch?v=9nfcn2khpX8&feature=share&list=UUEWUAaAcl8MXAjF0MLFrutA

     Should be receiving the rub strip and block in the next day or so and the front sprocket gasket so I will clean out the casing like Threepot advised and change the chain and sprockets then all being well it should be sorted

         Happy days and thanks for your advice
   

[ssevy]

It sounds like you have eliminated the engine and tranny itself as a possible source, and for that, the dyno worked well. I hadn't thought about the fact that there would be no suspension movement on the dyno when I suggested it, and thus the chain and sprocket alignment would be static, but your lack of results seems to confirm the sprockets/chain as likely being the source.