5 replies to this topic

[Gordo]

Hello, I have a Wassell trials bike with a Sachs 1251/5A in it. I have heard of and would like to put a BSA motor in it. I'm a two stroke guy and don't know anything about BSA single 4 strokes. What type / model / size should I be looking for? This bike will be 100% Trials.
Any help and advice will be appreciated. If anyone has a different or better idea on a 4 stroke motor for this frame, please chime in.
Thanks

[totalshell]

sell the wassell complete for circa a grand, buy a running d14 bantam for 500 and sell everything bar frame forks wheel hubs/ brakes and swinging arm for 500 hit eblag and buy wheels tank and a b40 motor
you should be able to turn out a trialler for less than a grand.

[Gordo]

OK, Now that that has been recommended, lets get back to the task at hand.
I want to know what would be a good 4 stroker to put in my Wassell frame.

[bult360]

Hi ,it depends what your local eligability rules will allow as for the year of motor ,but if thats not realy an issue .I would try a cub motor if you want to go early ,and if a later motor would suit why not try a tl series Honda, dead reliable and would have more than enough power for the wassell .The c15/b40 could be a bit bulky for your frame

[Woody]

BSA you have 2 choices really, 250cc C15 or 350cc B40. Basically the same engine as the B40 is an overbored 250. There are internal differences throughout the model years but the basic shell of the motors are the same so both use the same mounting points. Early are distributor ignition, later have no distributor points are in the side casing. Their production run spans either side of the 1965 cut off date, depends on your rules but both ages are used here.

Or there is the later 250cc B25 engine which isn't supposed to be eligible over here for Pre65 (ho ho) Again, same basic construction as the previous two but smaller crank assembly, better head design so it is a bit more responsive in terms of power.

Out of the B40 and C15, the C15 is generally preferred as it is consider to grip better (subjective really) The standard road C15 engine with the 7/8" inlet can be used by lowering the primary drive. Nothing else is needed really, cam, valves, compression, gear ratios all ok for trials. But you'd really want to pu a modern ignition on it. PVL works well.

Any other BSA 4 strokes aren't worth bothering with really, these are the most common and parts are readily available.

[huntmaster]

Woody, on May 13 2010, 08:26 AM, said:

Any other BSA 4 strokes aren't worth bothering with really, these are the most common and parts are readily available.

Could be. Good thing I don't have one of these! I better cancell that Rocket-3 trials project I guess!