Possible cause of my misfire

[bikerbob]

You will eventually get there by a process of elimination now the head has to come off to renew the gasket go for a solid copper one and don't forget to anneal it first this is important. Good luck.

[Swarfcut]

Minto. Before you take the top off, do research regarding the order of removing the head bolts. Then the pushrod replacement procedure, and the various tricks and  tips to get them back in place.  With the head off, worth checking the valve seatings, simple test is a dose of petrol down the ports, obviously none should pass the valve/seat. Could be the answer to rough running.

 Get yourself a book and write down everything you do to the bike. Saves having to remember all the little facts and foibles, and becomes a useful reference.

 Swarfy.

[Minto]

A note book is an excellent idea, particularly for my son, who has first dibs when I Kark it.
Reset the points this morning, didn’t bother the other day as I thought they were within tolerance, maybe my conversion maths was a bit out, (only got metric feeler gauges) cos it runs like a different bike today, started easier, no acceleration hesitation, pulls stronger, the only thing it’s still doing is spitting back through the carb occasionally when idling.
I’m going to strip the carb tomorrow see if it’s just some poo in there blocking a jet. I know these 276 pre monoblocs are known to be leaky, but it is a worry.
I’m going to pull the head, but probably be next month now (weekends are booked) and I’ll order a new copper gasket (any suggestions for best quality?) and give it a blast with the blow torches before fitting.
I’ve read a bit about the pushrod faf on refitting, I’ve got my own thoughts on how this can be overcome, I’ll let you know how that turns out as and when I balls it up.
Thanks to everyone for the help. Brilliant!
Jase

[Greybeard]

I wrote up my method for Rocker-box refitting a while ago. Search for the topic 'Push rod tips' in A7 & A10 Engine. I've just used the same method and it works well for me. Having the seat off the bike makes it possible with a bright torch, to check that all four of the rocker sockets are located on their pushrods. 

[chaterlea25]

Hi Jase,
Any wear on the slide of the 276 will lead to spitting back at tickover
Check that the engine responds to pilot screw adjustment, the 276 relies on a drilling in the jet block for a pilot jet
The jet block needs to be removed to clean it properly

John

[Minto]

GB
That's a cracking write up, really helpful and detailed. Thanks for the link, I'm pretty useless with this technology stuff.
 
John, cheers for the advice.
I'll check the engine response to the pilot screw tomorrow, at the moment it's adjusted 1 1/2 turns out, I'll see what happens when I take it out/in another turn.
Can you get replacement bits for these old carbs still?
Thanks

[scotty]

Jase

Hang in there !

With the wisdom of the guys on this forum and a few adult beverages you’ll have her in shape.

Parts for Amal carbs available from Burlen
http://burlen.co.uk/

S

[Minto]

Hi Scotty, thanks for the link.

[chaterlea25]

Hi Minto,
I have always found (with old 276 types) about 3/4 to one turn out works best

John

[Minto]

Hi Minto,
I have always found (with old 276 types) about 3/4 to one turn out works best

John

Cheers John, I’ll play around with those settings when I get a spare hour.
Jase

[Minto]

Hello to all
Had the carb off to strip and clean it out, the float bowl was decidedly grotty, crusty deposits in the bottom.
Blew all the jets through, wee lump of crud in the main jet, and gave it all a good dowsing with carb cleaner.
The bike feels great, more willing, no more spitting back through the carb, and starts better (unless I tickle it too much and flood it)
I still need to get the head gasket sorted, but strangely seems to have stopped blowing?? Or maybe I’m not looking hard enough.
Is there somewhere in particular  I should get the gasket from for best quality?
Thanks all you good good people.
Jase

[RichardL]

I'd. go with SRM, but I suppose C&D Auto or Draganfly would be other decent sources. The main thing with a solid head gasket is to thoroughly anneal it by heating all areas to a mild cherry red. Air cool may be best, but water cooling copper does not harden it.

Richard L.

[Minto]

Thanks Richard

[BSA_54A10]

I get all my copper gasket from Lanni at coppergasketsus.
A great person to deal with
Send him a tracing / rubbing / scan of your barrel & he will cut you a bespoke gasket for your engine rather than the max rebore size found in most kits.
Ask him to max the postage & he just keeps on putting gaskets in till the last oz of weight is accounted for.
You can then ebay the extras ( keep one for yourself ) at a slightly elevated price so you gasket is free.
He will also cut them in any standard US thickness .
Better still get some rocker cover gaskets as well and say goodnight Irine to top end leaks.

[muskrat]

+1 for Lani. I need my head gaskets different from std to account for my through bolting of the head & barrels to the c/case. Which reminds me I must order more. https://coppergaskets.us/
Cheers