Hitchcocks Forum

Hello everyone, would appreciate any comments on big end knocking noise which occurs only when bike is started after being on side stand. Lasts only about 10 to 15 seconds (although it seems longer!) then clears. It's as if all the oil drains out of the big end and timing chest when it's on the side stand, then takes a while to build up pressure again in the big end bush. Never happens if the bike has been on the centre stand, or at any other time.

Bike details: 2008 Bullet 500 4 Speed Classic, total mileage approx 2500, fitted 535 big bore kit with forged piston & 2mm compression plate under barrel, free flowing exhaust & usual Mikcarb mods.

First noticed problem after stopping at services on way back to Southampton from Festival of 1000 Bikes at Mallory in the summer.

Since then, have fitted uprated oil pumps from Hitchcocks, carefully lapped in and with proper clearance on plungers(original factory pump plungers fouled on timing cover), good flow of oil from rocker box when union is loosened, but has not made any difference.

Any ideas would be welcome, or is it a case of "They all do that, mate".

Thanks & regards

Nigel

Nigel, for starters don't run them on the sidestand the scavenge pump is on the right hand side and when you lean the bike over on the sidestand it can't pickup the oil from the sump. This won't cause the noise you are describing but running it on the sidestand isn't a good idea. There is a reason factory fitted sidestands have a cutout switch

Hi Norm

Thanks for the response. I have never run the bike on the side stand, it's when the bike is started after it has been on the side stand for a few minutes or more.

I don't often use the side stand, but when I do, I get the knocking noise when I pull the bike upright and start it............

I remember reading a post somewhere from a chap who found the oilways in the timing cover had not been properly drilled at the factory, restricting the oil flow. Wasn't aware of this potential problem when I fitted the uprated pumps, do you think this could be worth investigating?

Thanks

Nigel

If it didn`t make the noise with the original pumps, why not refit them? You were fixing something which wasn`t broken.

Hi Leon - as mentioned in my original post,I first noticed the noise when the original pumps were fitted, which was the main incentive for fitting the uprated pumps.

When I first posted, I half expected others might have had similar experiences, but as no-one else seems to had this issue, it makes me think there must be an oil circulation problem.

I think I'll give our hosts a call, see if they can give me any pointers.

The knocking noise meant the Bullet was left behind when I went to the Island for the Classic TT last year (took a W650 instead) but I must resolve it in time for this year's Classic TT!

Nigel

Nigel, have a look inside the rocker blocks and see if there is any sign of whitemetal in there, not sure why it would only knock after being on the sidestand but something isn't right

Hi Crusty: What about trying a synthetic oil; the molecules are supposed to be magnetized and stick to the metal of the crankshaft, so not draining away. I know this is overkill oil for an Enfield, but it might be a temporary solution for your planned trip. Best of luck.

Very interestingly, my 500 classic make the classic 'primary chain tapping the cover noise', But only if the bike is facing slightly uphill. Level or a few degrees downhill, and it sounds as sweet as a nut!

Crusty, I think it's a case of mis-diagnosis. If you were starving the big end it would have given up by now. As Scaly hints, I think it's mis-alignment of the primary chain or clutch, possibly even the alternator rotor. I'd strip the primary and check everything is properly locked onto the relevant shafts, a little end float on the primary sprocket or clutch can make a huge racket!
REgards, Mark

Crusty and Scaly???


Nice one mark, we sound like the kiddies act at the big top!



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