Mastiff starting issue -- now fixed

[Silverstripes]

Hi all

I have a few starting issues with my Mastiff. It starts eventualy from cold by..... Operating the choke for 4 engine cycles, then open the choke and crank the motor with just a very slight throttle opening and then it chugs into like. It sounds over choked as it chugs away with the starter running and then the engine speed overtake the starter and I am away !!

I have had the choke mechanizum out, cleaned it all and reassembled. When it does start if I operate the choke slightly then it starts to chug as if its overfuelled. It does not run clean until it has warmed up a bit........ When I first had it 4 + years it used to run fast on the first part of the choke until choke was open then it would tick over. Now it does not want to tick over and has to be kept running on the twist grip. Clearly the choke is working I think working too well but it needs some choke to start.

Just as a thought does the choke rely on the pilot jet for fast running under choke conditions. Once it has started then it restarts all day with no issues.

I am Bemused

Adrian

[Srinath]

I believe the choke on my 660 skorpion sucks though the metal tube that is sticking through the wall of the float bowl.
Your bike may or may not have that same setup.
Cool.
Srinath.

[harold]

Have you tried adjusting your air pilot screw? The old trick of turning a full turn in and trying it, and if worse, then a full turn out and try it. One way or the other should make it run worse, or better. If neither makes a difference, your pilot jet may be plugged up.

[Silverstripes]

Fixed

It was a blocked pilot jet. A small amount of white crud. It was a real pain getting the carbs off, evervthing seems to be in the way including the rubber oil pipe. With the carbs off I was able to strip them down. Remarkably clean with next to nothing in the float bowl. Passes a wire brush bristle (1) through the jet and then rebuilt.

WHile it was in bits also did the valve clearances as these if tight can cause poor starting and yes the inlets were very tight. Also while I was at it did the exhaust valves.

It now starts on the button and when the choke is used the revs build higher just as they should.

All is well with the world

Adrian