Scooterotica

eibargum wrote:you may be onto somthing there Seeker, when the front forks are loose the whole bike shake,s, even on the stand.

I only say this as I recently transferred a whole scoot from one frame to another and thought "oh I'll tighten everything up later" in the rush to get it together and then forgot to. Bits have been dropping off here and there since then. I rode up to see some friends in Gent over the weekend and lost both of the bolts from the lower damper brackets simply because I never really tightened them properly.

Same thing for the forks. I had a "wicked shimmy" (to quote Apollo 13) until I realised the headset was something else I'd forgotten to tighten properly. It's probably the worst thing to vibrate other than the engine mounts if not tightened right up.

Ben

some good points to look for there celt.....especially as your scoot is in kit form all over my garage!!!!!seriously ive got my suspicions over the build of the bike,celt has spent a lot of money on this engine and i can relate to his frustrations..i have never had vibration issues but i always make sure the bike is "tight"
anyway hes insisting broady checks the crank himself which will give him piece of mind,im not sure the engine mount holes are in the correct position?wot is the correct position?
the front end...well we can check that,i notice a rumble on the front wheel bearings too,the bike is an early indian gp,and it seems very "light" in comparison to other bikes ive had
get your latex gloves on mr celt.......

camel wrote: anyway hes insisting broady checks the crank himself which will give him piece of mind

MB Alpha cranks do not always without problems despite the price tag. I was never happy with the Vibes my TS1 had after I fitted mine.

After the new mag side seals went after not many miles I took it out and had it checked. It was miles out.

To be fair to MB they did have it re-pinned for me inside of a week, But we all know how much grief it is to strip the engine to get the bugger in and out.

As Camel has mentioned I'm of to MBD in the morning. Spoke to Mark at Euro Lambretta which he said he has known a couple to be out and that he has a jig set up to test. I will let you know what the findings are.

I can't dismiss the other posts concerning wheel or headstock etc, but this was not apparent on old crank and I have done less than 500 miles on Alpha. I am aware that fork bearings loose fittings can occur anytime to cause vibration.

Had a similar problem with my MBD crank, the supplied woodruff key was too large for my flywheel n stopped it centralising properly, took 500 micron (half a mil) off the key by hand grinding, removed the sharp corners and all ok. My indicator was a fuzzy strobe timming light mark at max revs.

Honeymonster wrote:Had a similar problem with my MBD crank, the supplied woodruff key was too large for my flywheel n stopped it centralising properly, took 500 micron (half a mil) off the key by hand grinding, removed the sharp corners and all ok. My indicator was a fuzzy strobe timming light mark at max revs.

I'll have to have a look at that

Been to MBD today, Mark checked the crank (out of sight ) He said that it was running as true as it possibly could!!

His opinion on the lightened flywheel causing more vibration is, it is probably out of balance more than the heavier flywheel.

His first question to me was does the engine touch the frame at the manifold....which because of the packer the barrel is moved forward slightly and can touch the frame. I use eccentric cones because of this, so the engine does not touch frame.

He asked about the mounts position, but stated that placing them out is not a big issue

Also asked what piston and exhaust are used, I said Asso and a JL3. He said the Asso piston can cause vibration and that his race pistons will give more balance. Also with the exhaust the power comes in around 45mph so would feel more vibes around this mark. I do get more vibes from just below 40mph-55mph. When accelerating fast through the gears the vibration is less notable.

I have checked for play in headstock and forks and all is tight. There is a negligible rumble on spinning the front wheel. So time to rebuild and probably back to square one :baddevil:

Richie, is it better, or worse, when it's fully loaded with luggage? Maybe an idea to change or move the mounts whilst it's in bits anyway? Maybe also rebuild it all with someone else, just in case they can see something which you are blind to

Hope you find it

Paul

storkfoot wrote:Richie, is it better, or worse, when it's fully loaded with luggage? Maybe an idea to change or move the mounts whilst it's in bits anyway? Maybe also rebuild it all with someone else, just in case they can see something which you are blind to

Hope you find it

Paul

Paul mate

It wasn't the scoot that I went to the euro on, so I have no idea what it's like under load.

Now that the engine is out, I was thinking of taking it to Barry Turners to check engine mounts as they are slightly out and maybe get them re-positioned.

Also the scoots at Camel's which he has helped in stripping and is helping with the re-build. One point which I have noticed and Camel has again pointed out is the scooter is very light. Compared to my other GP it is very noticable, I shouldn't think this has any bearing on the situation but you never know.

Are lass,s indian GP is also very light, its only got a muggy in but its as smooth as a sowing machine so i dont think the fact that its light as any bearing on your problem.

Celt, if I was you I'd get the crank checked independently, that way there'd be no room for this and loads of this .

An old saying my mum used to tell me springs to mind, "If you believe everything you hear you'll eat everything you see".

Another one was when I'd say I wish this or wish that, she'd say, "you can wish in one hand and s**t in the other, see which one gets full first?" wise woman my mother,good luck