Search found 52 matches

by David Smith
Fri Oct 27, 2023 5:52 pm
Forum: Four stroke
Topic: Mystery cause of sticking inlet valves on Mk II engine.
Replies: 36
Views: 2377

Re: Mystery cause of sticking inlet valves on Mk II engine.

Paul It might be an oil carburisation / burning problem if you are not using the oil cooler. Experience with racing Honda Cb77's in the IOM, notoriously hot running engines, was that even R40 castor oil was turned to lacquer and vinegar in 6 laps with high consumption without an oil cooler. Another ...
by David Smith
Thu Oct 12, 2023 5:34 am
Forum: A Bad thing happened to my Ariel
Topic: KH Crankcases
Replies: 15
Views: 3017

Re: KH Crankcases

Rob
Very sorry to hear this, the whole area is a disaster as far as access is concerned, Hopefully the job will be stronger than original when welded up and at least the engine should go back together with no problem

Regards


Dave Smith
by David Smith
Tue Sep 26, 2023 11:40 pm
Forum: Four stroke
Topic: Oil weep from feed pipe nut
Replies: 21
Views: 985

Re: Oil weep from feed pipe nut

On my KH 500 it did that for a while and then became dramatically worse, the pipe was cracked around the soldered on olive
by David Smith
Mon Sep 18, 2023 6:47 am
Forum: Four stroke
Topic: Oil carry over- SQ4
Replies: 6
Views: 402

Re: Oil carry over- SQ4

Is it rebored? You may need to use running in oil if it is
by David Smith
Mon Aug 28, 2023 11:14 pm
Forum: A Bad thing happened to my Ariel
Topic: Another prat pulled out of the side road without looking
Replies: 15
Views: 1479

Re: Another prat pulled out of the side road without looking

Paul Very sorry to hear this and hope your wrist is not too painful, and the sq four is not too badly damaged. The standard of driving by many is truly abysmal these days. I am just getting the KH back together after my recent front wheel puncture and unexpected arrival on my friends driveway! Best ...
by David Smith
Sun Aug 27, 2023 3:53 am
Forum: Four stroke
Topic: How hot is hot enough to straighten a footrest
Replies: 5
Views: 368

Re: How hot is hot enough to straighten a footrest

Thanks Chaps
Mapp Gas torch and Oxy Acetylene eventually proved hot enough to straighten with a 2 1/2 lb copper and hide mallet
by David Smith
Sun Aug 20, 2023 10:48 pm
Forum: Four stroke
Topic: How hot is hot enough to straighten a footrest
Replies: 5
Views: 368

How hot is hot enough to straighten a footrest

Repairing the accident damage to the footrest on my KH. I have sourced another one, but that's a two piece affair with the peg bolted on. My attempts with a map gas torch were completely ineffectual, and I suspect the material is malleable cast iron or SG Iron as they say now. Does anyone know what ...
by David Smith
Wed Aug 02, 2023 8:37 am
Forum: Four stroke
Topic: Mystery cause of sticking inlet valves on Mk II engine.
Replies: 36
Views: 2377

Re: Mystery cause of sticking inlet valves on Mk II engine.

Paul Do you run an oil cooler? Experience running Honda cb72 engines( notoriously hot running in race condition) in the classic Manx GP on Catrol R30 Castor oil broke the oil down to something resembling vinegar with brown lacquering all over including the bores. The following year bored out to a fu...
by David Smith
Mon Jul 31, 2023 2:03 am
Forum: Four stroke
Topic: AMAL 376 monobloc Carburettor refurb
Replies: 11
Views: 656

Re: AMAL 376 monobloc Carburettor refurb

Simon https://vintagebikemagazine.com/technical-articles/amal/ " A note about slides: The is a lot of folklore about the slide clearance in Amal carburetors. To insure the slide will not stick in the bore from the mounting hardware being over tightened the slides are given .0035″ to .004″ clear...
by David Smith
Sat Jul 29, 2023 10:14 pm
Forum: Four stroke
Topic: AMAL 376 monobloc Carburettor refurb
Replies: 11
Views: 656

Re: AMAL 376 monobloc Carburettor refurb

Well the amount of distortion and metal removal is very small and round unworn slides display no movement in any radial axis. Worn slides unfortunately do and are a waste of time, but the result is a serviceable body. The 0.004" clearance was a revised increased clearance as users were distorti...