Hitchcocks Forum

Hi all

I recently bought a 350 Trial that was built by Watsonian. It is a 2008 350 Bullet with a pancake airfilter and free flow swept up exhaust.

It really struggles to get past 55 for some reason. I have removed the std carb and cleaned it, have fitted new points and a new plug but these havnt solved the problem. It accelerates fine but the top speed is less than i would have expected. I have tried setting up the carb and it seems happiest with the main needle out 3/4 turn from closed.

Can anyone advise what to look for next or am i just expecting too much perhaps ?

Many thanks

Ant

These bikes were sold with carbs that ran very lean, for emissions dodging reasons. If you look under the carburettor section of the accessory shop catalogue our hosts list different main jets and throttle slides for restoring performance to some extent in both 350 and 500 models, together with a little table of different jets required depending on air filter and exhaust. If you haven't already seen it there is also a note for tuning Micarbs in the technical section.



A.

Many thanks for that.

I made a note of my set up and it is currently running std throttle slide with a 100 main jet. Pilot seems to be standard. I have ordered the 105 main and 2 slide with a 27.5 pilot. We will see how that runs.

Cheers

Ant

If it's a Trials bike is the gearing low for off road work? My own 350 Works Rep Trials (Redditch) is very low geared, 55 is all it's got on the road.

REgards, Mark

Hi Mark

That's an interesting point. I will see how the re-jetting effects performance and will then more than likely look into gearing.

Rather than start stripping down the gearbox could I replace the std 16T front chain sprocket with a 17T one ? Would I need a new chain ?

Regards

Ant

According to the Parts Book 16T is standard for the Indian 350 but I'm sure you can pull 17. It depends how worn your chain is really as to whether you need to replace it. It's considered good practice to renew chain with sprockets but as you're only changing one you might get away with it.

REgards, Mark

Well, an Indian 350 Bullet will start struggling at around 55. The upside is that it's a nice soft engine and will probably outlast a typical 500.
Having said that, do get the carburetion right. With a free flow exhaust and filter, you should have a bigger jet and possibly cutaway as well.

I found my Indian 350 Bullet high geared, and unwilling to pull much past 50mph. I went to a 15 tooth gearbox sprocket which made it far more flexible without losing any top speed. I'm not sure that going up to 17T will be beneficial.

I was thinking that the Watsonian 350T lost a lot of heavy bits during the conversion and should therefore pull a higher gear? My Redditch Trials' upper cruise speed is 55 with 60 available for emergencies. It would probably do more but the comp ratio is quite low, something I'm changing during the refresh I'm doing at the moment.

REgards, Mark

Shedding weight might make a bike a bit quicker but not really any faster.