new dommie prob

**mikechips** · #1 4 Oct 2003

further from my hot lumpie running dommie topic a new problem has risen up.I have previously had problems with tick over and hot running so I obtained a higher rating plug as per manual and fitted it After starting all seemed well and tick over fine.So I gave it a trial run.As I came to a halt when the engine just stalled and would not restart.To add to this there seems to be a clonking sound coming from top and bottom end when I try to start it and there is no attempt by the engine to fire.Please any ideas???
I know the clonk does not appear to be starter motor.

**martync** · #2 5 Nov 2003

a cause could be your valves or one of em going tight and thus may need adjusting, I don't know if there shims but it easy to do if you have a manual.

**mikechips** · #3 6 Nov 2003

thank you for your reply,but after close examination of the noise I decided to take off the head.Big ole problem.One of the exhaust seats had fallen out into the path of the piston and cracked the head.Tried to find used one,no joy.New one £550 plus vat.
decided to get old one welded,redrilled and gas flowed.Should be back soon.This is a common problem apperently , Dommies are prone to running hot(so I am told)mine was caused by a split in the seperator between manifold and carb.Cheers for replying.mike

**martync** · #4 7 Nov 2003

no need, you can get them fixed (welded and ground back down etc.) and it costs about 40-50 per seat, many places do it but there is a good one near donnington which advertise in the back of motorcycle news.

**mikechips** · #5 8 Nov 2003

cheers I have used the cylinder head shop based I think in Peterborough(used to be Wimbledon)very helpful people and seem to know what they are talking about.The chap said he had done about a dozen in 2 years so seems like it is a very common problem.He had another one there with mine,same prob.
I will let you know how I get on
regards
mike