Getting there

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Getting there

Postby mikeydpippin » Thu Jun 20, 2019 1:20 pm

1957 G3 Timing now spot on and auto advance flicking as it should, Bike starts and runs albeit lumpy, and bit of backfire through carb, I,m guessing this is due to using the old carb inlet gaskets.

Two questions.
How many paper gaskets are needed with the spacer on carb inlet ie. is a paper gasket needed either side or just carb side of the spacer.
And
After fitting a new rocker box gasket and really tightened the bolts as far as I,m brave enough to, I have a very small weep of oil leaking onto the spark plug, is there a gasket sealant on the market that would seal this if I fitted a new gasket, putting a sealant either side of the rocker gasket.
Looks as though the rocker surface is not quite level.
Mike

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Re: Getting there

Postby Rob Harknett » Thu Jun 20, 2019 2:34 pm

I have always put a little red Hermatite both sides of the rocker box gasket. You do fit a gasket each side of the Carb spacer. The carb may also have an O ring in it. Carb flange face a spacer faces can be cleaned up flat using a sheet of sand paper on a flat surface, Like wise the rocker box surface, so that is flat even if the head is so quite so.

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Re: Getting there

Postby SPRIDDLER » Thu Jun 20, 2019 2:57 pm

mikeydpippin wrote:And
After fitting a new rocker box gasket and really tightened the bolts....I have a very small weep of oil leaking onto the spark plug,

Not uncommon. Many a thread has been stripped by over-tightening in an attempt to stop that weep. There is often crud - old gasket scrapings etc - at the bottom of the blind rocker bolt holes and even though the bolts feel tightened they are merely bottoming out on the crud without compressing the gasket sufficiently. A 5/16" BSF tap clears out the muck a treat (if you feel in need of a treat).
I poke badgers with spoons.

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Re: Getting there

Postby Mick D » Thu Jun 20, 2019 3:04 pm

Hi

Assuming the carb flange and insulator are flat, if the carb has an "O" ring in the flange no paper gasket is required, a paper gasket should be used between the insulator and the head.

I use Wellseal to seal all of the joints including the rocker box as a matter of course - works for me.

Spitting back is normally indicative of a weak mixture at low revs - if the inlet tract has no leaks try adjusting the pilot air screw to richen the mixture or even close the choke a little to see if things improve.

Regards Mick

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Re: Getting there

Postby Rob Harknett » Thu Jun 20, 2019 3:24 pm

Have you got the engine warmed up enough before setting up the carb for which suggestions have ben made. Sometimes a bike will need a good run of a few miles, if it has been standing.

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