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Tappet noise

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Tappet noise
Started at 10:25pm on the 10th October, 2007 by John R
John R Subject: Tappet noise
I find the tappet noise from my 350 classic a bit much. I have adjusted them on the tight side, but even so, after a quiet start they are rattling away after about a quarter mile. Now, I know "a noisy tappet is a happy tappet"-but not necessarily a happy rider. Most pushrod engines I have had to do with start off noisy and go quiet as they warm up.

I assume the reason is that the barrel and head on a Bullet expand more than the pushrods on these bikes. I use a solid copper head gasket and, copper having a high rate of expansion, I wonder if lapping the head directly to the barrel helps. I also wonder if a standard gasket is any better?

Does anyone know if an alloy barrel expands more or less than cast iron?

Failng this, Mr. H, might not next years catalogue feature pushrods made of something which expands a bit more?
Posted: 10:25pm 10th October, 2007
dean hoare Subject: Re: Tappet noise
a noisey 350 top end may be a result of scratched piston ive had sevral engines that sound tappety ,no matter how much i adjust tappets ,replacing piston and rings completely cured problem despite only minor marks on original piston ,fitting a good quality european piston quieted things down further, its not unusual to find bent pushrods on bikes that are ridden hard and this makes correct adjustment difficult, as for alluminium barrel ,ive noticed that top end noise increases particulary on 5oocc ,fitting a alloy barrel to my current 350 cc increased mechanical noise somewhat ,i believe the problem is reduced on english sand cast alloy barrels, cheap alternative are ear plugs
Posted: 10:43pm 10th October, 2007
glenn Subject: Re: Tappet noise
Year same here. My 350 sounds like half a dozen skeletons having an orgy in a biscuit tin. Goes well though.
Posted: 11:38pm 10th October, 2007
craig Subject: Re: Tappet noise
Says on my Enfield Belt "Loud Valves Save Lives".............Any way. Its part of the Mystic Dark art of running a Classic, :)
Posted: 08:49am 11th October, 2007
Mark C Subject: Re: Tappet noise
Hi John.
When i got my bullet some years ago,the tappets made an awfull racket that no amount of adjusting would fix. The problem turned out to be the oil pump worm had come loose,causing backlash in the cams.
To check for this,turn the engine over very slowly on the kickstart with the decompressor open, or plug out. If the is backlash you will hear a loud metalic click as the cam follower goes over the nose of the cam. Wear in the cam spindles will give the same results.The pump worm is a left hand thread so anticlockwise to tighten.
Mark C.
Posted: 01:15pm 11th October, 2007
John. Eastbourne. Subject: Re: Tappet noise
This subject is an old chestnut on this site. I will say no more than to mention the following website, which is a must read for any Bulleteer, and an eye opener, insofar as it dispels many myths about Bullets.

www.cybersteering.com/cruise/feature/bullet/

bullet.html

B.R.Gurunandan knows Bullets backwards. There is an excellent section on tappets, which is a completely different angle on the factory guidelines. Read and enjoy!!
All the best, John.
Posted: 06:00am 12th October, 2007
david seaman Subject: Re: Re: Tappet noise
I do not think it possible to iliminate the mechaniclal clatter produced by a bullet engine but you can reduce the amount that you hear when riding the bike.
Have you noticed that the mechanical clatter appears more when the petrol level in the petrol tank is low? This I suspect is because the bolt that retains the rear end of the tank is also used to retain the engine steady bracket which transmits mechanical noise from the engine to the petrol tank which acts as a echo chamber.
I reduced the degree of mechanicl noise that I heard when riding the bike by taking the following actions.

I cut the two rear mounting lugs off the rear end of the petrol tank and had a small brass boss braized onto the rear end of the petrol tank ,like the ones used to retain trials tanks.I placed central heating pipe insulation rubber along the frame tube that passes under the tank.Put the tank back into position and pass a thin cable tie around the boss on the tank and around the frame tube and pull tight.This will retain the tank ok and considerably reduce the mechanical noise heard when riding the bike.

hope this helps David
Posted: 07:12pm 24th October, 2007

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