Hitchcocks Forum

Hi all

I've got a mystery intermittent clanking noise coming from the engine of my '94 Indian Bullet. I stripped and worked on the bike over the winter, and the engine's been decoked and had new Samrat rockers, head gasket, oil filter, iridium plug and ignition advance springs from our hosts here. The engine was running well before the rebuild, though the intake rocker was a little loose and noisy - hence the new Samrats.

The noise is an alloy kind of clank/click, and it's intermittent, occurring once every 5-10 seconds when the engine idles. It's hard to tell but it seems to be coming from the timing side. It wasn't present when I first started the bike after the rebuild, but started up soon after. It originally seemed to disappear at higher revs, though I'm not sure this is the case any more. It could also be my imagination but it seems as though it's getting louder and more frequent.

I've checked all the usual suspects and can confirm it's not the head steady, the primary chain tensioner, the alternator, or any other obvious nuts/bolts on the crankcases. I also don't think it's the tappets - I've checked tappet clearances, correctly torqued rocker blocks etc. It also seems too irregular a noise to be anything in the valve chain. The bike also starts first kick and is utterly lovely in every other respect - pulling strongly and generally behaving itself. Idle is smooth and doesn't miss a beat - there's just this damned clank which puts my teeth on edge every 5 seconds.

I've been reading old threads on here, and it seems as though it's a similar issue to the one Simon had in the 'Clank is back' thread. I could be being stupid, but reading that thread it seemed to stop short before a solution was found - does anyone know what the cause of Simon's mystery clanking noise was?

I'll get the timing cover off over the weekend and let you all know the condition of the oil pump parts - it's occurred to me that the spindle might be slipping a tooth every now and then.

Many thanks in advance for any help folks - all the very best - Alasdair

It could be the primary chain loose, not unknown!

REgards, Mark

Thanks Mark - that was my first thought too. Unfortunately that's checked and sorted and the mystery clank continues...

Hi Alasdair, very unlikely, but could you have a slightly bent cam follower? As I say, unlikely, but if the noise is that infrequent it has to be something that is rotating much slower than the crank. A slightly bent follower's foot might contact a cam gear wheel or even the crankcase wall as it rotates at its' own speed. Also check the pushrods are straight, for the same reasons. Cheers, Paul.

Hi Paul. Many thanks for your thoughts - I'll check both when I have the timing side off, tomorrow hopefully. What's keeping me puzzled is that it's a noise that's definitely started up since I fitted the new parts - which makes me think it's almost certainly something I've done during this process. I did have the pushrods out and about at one point, so I'll definitely check those. I'll keep you all posted anyhow! Cheers, A

Something stiff in the valve train that's holding the valve open until the compression closes it? That could be intermittant and would be quite noisy. And you just fitted new rockers?? Just a thought.

Yes I had exactly the same problem and it was utterly infuriating. I replaced the valve seats, the rockers, the timing chain and numerous other bits and pieces. I think it is now gone (I haven't heard it for months) and what it was I believe it was the oil pump drive slipping teeth. I checked the oil pump drive spindle and found very small but distinct witness marks on the tops of certain spline teeth. I put in a new spindle and worm drive nut and replaced the old heavier springs at either side of the pump that act as the only oil pressure relief valves in the Indian bullets. I was also using a mono grade 50 oil which I have now changed for a multi grade. The good news is the bits are quite cheap and freely available (assuming I've finally nailed it!).

[center]


Could be either valve jamming. Coincidentally, I had the same problem with Tornado, my 1994 bullet, I called it the 'clank'.

It was not until Chris the mechanic took the head off, that he found the valve guide was held in place with a ton of chemical metal or similar.








Every so often, the exhaust valve would stick open and blow the carb off, but the clank was always there. Go to 2:00 in the vid below, and see if this is the same rattle!






If so, we never found the cause, and I don't worry about it. It does depend on wether Tornado ism pointing up or down hill though.

Just a thought, could it be the cams sliding laterally on their spindles and bashing into the timing cover with excessive end-float? A.

Check that the hardened valve end-caps are not worn/dished and that they are a tight fit on the valve stem. If they are worn/loose AND you have swapped them around you can get a similar noise.


Then check rocker end-float.