JIM SNELL SHOWS convert older GasGas Trials machine (1993) to Keihin PWK28 carburetor

Jim Snell shows you how he made an air-box modification on this older GasGas to allow for much more air-flow and the use of the larger PWK28 KEIHIN carburetor.

[@thomaswykes3647]

I appreciate your videos featuring the older Gas Gas bikes - it gives me faith to stick with my 1993 GT25 Contact T. What advantage does the Kehein carb give over the old Dellorto?

[@TRIALSPARTSUSA]

HI, The PWK28 carburetor is larger in general, and besides being 2mm larger thant the 26mm Dellorto, the rear intake bell is substantially larger and it will flow a lot more air (especially if you also enlarge the intake tract from the air-box as I did in this video) My bike is bored to 256cc (Originally 238cc) This carburetor make a big difference on the larger GG engines (327cc and 338cc as they are almost under carbureted with the 26mm Dellorto) For sure my bike runs better with the Keihin but a lot of that is the air-flow improvements made with the modifications to the filter box. For most riders with the smaller GG engines, this carburetor has no large advantage. The Dellorto is an excellent carburetor, but some people are convinced the Keihin is better and of course the Keihin is Japanese made so is perceived as being of better quality etc. The Keihin throttle action is smoother and takes noticeably less effort at the twist-grip. I run the vintage aluminum-body slow-turn AMAL throttle assembly that also uses a bearing on the cable wheel. On this bike, with the Keihin and that AMAL throttle, it is almost too light of throttle twist effort. Thank you for watching and best regards in sport, Jim