Hello all,

At the moment i`m restoring my sherpa 198A with a mk2 concentric and i just cant get the thing to flood from the tickler.

I`ve had the carb in bits probably 2 dozen times now, have checked everything is clear and put a new gasket in.

The bike runs fine once its started which i can only do by taking the plug out and `priming` it with a drop of petrol.

I`ve got new crank seals for going in so i`m hoping this will solve the problem. I`m wondering if the jets are wrong or there is even a jet missing. The float chamber is filling up fine and i`m at my wits end!!!

If anyone can help or as had similar problems with this type of carb any advice or comments would be greatly appreciated.

Its the original spanish Amal so i`d prefer to keep it as i want to restore the bike as original as i can.

Hopefull Wishes !!!! Steve

If your Bultaco is fitted with a Mk 2 Concentric there is a cold start lever which opens another fuel passage when the lever is lifted.

My Montesa 349 with Mk 2 concentric was also bad to start. The problem was a blocked cold start jet, this jet is fitted in the float bowl at the bottom of a deep hole. To reach the cold start jet the float bowl has to be removed. The cold start jet is the same design as the pilot jet but may be a different number. Unscrew the cold start jet with a good fitting screwdriver and clean with carburettor cleaner. Check the hole the jet fits in is clean too. Refit the jet and see if this has cured it.

Hope this helps.

Pilot jet usually 20, 25 or 30. Cold start jet normally 50. Also check rubber or viton sealing disc on the bottom end of the brass cold start plunger.These come adrift or swell or distort with age, big source of trouble with mk 2s and mk 1-5s

Thanks Tayld, i`ve had the cold start jet out a few times and everything seems clear and i`ve also blown air through the brass `tube` that goes down into the bottom of the chamber at the side of the plunger. It all seems to be fine.

And thanks Bigwig, the rubber disc is good but i will check this weekend to see if the jets are right now i know the correct sizes.

Gday, something is weird if it wont flood using the tickler. Is the fuel supply to the carb flowing free? If that carb has the filter under the bowl on the inlet is it clear? Is the float level parallel to the top of the bowl?

Cheers,

Stork