Hi new to the forum have spent awhile looking for answers but can't find a definitive.  Just bought a 320 sherco registered 57 pl ate has a Pwk carb, it bogs when throttle opens quickly either in neutral or when asking to lift the front end without clutch.  Have just ultrasonic cleaned the carb and jets then blown thru with air.  No difference.  Does any body know the factory jetting sizes and needle position. Any help appreciated 

Edited July 14, 20197 yr by Fordbell
Bad spelling

The whole fuel system needs checking and making sure pipes and the fuel tap are clear. Tank breather clear, Bogging as you describe may well be incorrect main jet but there are other factors that can bring this issue up. Have you checked the exhaust for excess clogging. Factory jetting may not be what you want as you have a non standard carb fitted. Some one will be along shortly with advice on jet sizes unless you contact a supplier of the carb fitted to your bike.  

Makes me wonder if you know the fact that most 4T's bog when opened quickly, except for the FI bikes. Requires some adjustment in riding style.

Did anyone ever get the carburetion sorted on the 320?

Thanks for the replies. Section swept Do you know which carb should have been fitted as standard and will the main jet have an effect on the initial throttle response? Or should I look at Pilot jet? Copemech is it worth fitting a slow action throttle to loose the bogging I have only ever ridden 2t trial bikes than

 

Hey. The airmix screw located on the airfilter side of the carburator must be turned clockwise to the bottom. Then turn it 3/4 of a round backwords. My carburator is the PWK with the Sherco promt system. This was made to eliminate this problem. My bike is a 2007 model. It was not fitted on this so i bought it later on. It came as standard in 2009. If you have a standard PWK you must turn the idle speed slightly up so it does not have to pick up revs from a very low idle speed. This will help. The the float must be at the right level. When you hold the carburator down-side up there should be 21mm distance between the bottom of the floats and the flat underside of the carburator housing. The pilotjet was 42 on the 2009 and 45 on the 2007. 

 

That's great thanks for the information I will give it a go and see if it can be improved 

The SPS carb is totally different in the lower part. It is an improvement, not perfect yet works well if idle is set higher.

hi thanks to all for.your replies.  finally had another look and the needle was set with the clip at the very top i moved it to the middle,richened it, and the bog has dissapeared happy days 

I would have thought bogging down on a 320 was a safety feature to avoid landing in the tree tops...?