Sticking Throttle & Float needle

Posted by Arthur Farrow on Jul 05, 2020; 3:18pm
URL: http://silk-motorcycles.221.s1.nabble.com/Sticking-Throttle-Float-needle-tp5001969.html

My bike has developed a habit whilst stationary of throttle sticking and the revs go wild! This is a relatively small opening. Only way to stop is to cut the ignition. Has not yet done it in motion, but then I've only manged about 50 miles before the next lot of trouble shooting

The carb is in good order and the slide clean. I've read about the issue on other posts but as if often and annoying the tread fizzles out with no report of cure. One fine fellow said use as stronger spring ( mk 1 concentric) and another reported the chrome slides don't stick . Mine is the anodised alloy version.

What is the latest knowledge on this issue please.

BTW : I do have a cracked inlet rubber ( new one on order)

Also had a problem with that wretched carb flooding into the engine when stopped with petrol on. Discovered my Carb (Mk2 34mm 2900 series) had the very small brass needle as fitted to monoblocs and Mk 1 concentric whereas normally it looks like the needle is a big Ally one . I bought a new float bowl to match the big needle in the stay up kit I bought ( RGM Norton was much cheaper then Burlen) as I read somewhere needles can stick and the ally one is the cure. Maybe mine being an early Silk it had one of the first made Mk2s (engine is no 4) Anybody any thoughts here. So far so good.

Naturally i asked Burlen by e mail several times and left message, but as usual their post sale customer service is dreadful so no reply. Would not mind but in the last year have bought 5 new carbs from them . Matchless, Black Knight and a Commando.

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