Forum

[PeteF]

I already have a free flow exhaust and filter. If I do go for the head I will have to get a bigger carb anyway as the tuned head is opened up to 28mm. While I had the head off I was also considering the forged piston which ups the c/r a bit and is better made than the original. Trouble is, the engine is so well mannered as it is and I don't want to spoil that.

[Dean]

If your valves look iffy, I would go with the tuned head. My 350 had a burnt up exhaust valve and by the time I bought the performance valve kit, new seats and paid the machine shop I could have got the tuned head for a few bucks more. Teaches me for being cheap.

[Geoffers]

Hi Pete,
I went down this route with my 350 (Bertie!) and have been pleased with the results. I had the inlet port opened up to 28mm and both ports tidied up. Fitted a 26mm Mk.1 Concentric as I was advised that the 28mm would give more power at the expense of mid-range. Replaced the knackered rocker assemblies with the alloy Samrat items (Oil holes reamed out a bit). Also fitted an 8.5:1 piston plus the Hitchcocks short Indian silencer and long front pipe - free-flowing though a bit noisy! After some careful jetting the top speed rose by about 10mph to just over 70 and he’ll easily cruise and climb gentle gradients at 60. Fuel economy has suffered a little bit, but I suspect the main jet is a bit too big - better safe than sorry on that one! I jetted it with the air filter housing connected up but no filter - we never used to have them and I haven’t noticed any ill effects. This power output seems to be at the limit of my standard clutch so I didn’t bother with the sport cams. I know you can upgrade the clutch springs but I have a damaged left hand and can’t manage the extra clutch pull. All this has made the bike much more enjoyable, especially on longer rides with my mates on bigger bikes. Hope this is of some help or interest.
Cheers,
Geoffers

[simon]

I've got a slightly warmed 350 and its performance is excellent. I tuned the head in that I ported it as the ports were a rugged mess and port matched it with a 389 1 1/8" carb. I put the 8:1 piston in and the improved Hitchcocks cams. As many have already heard ad nauseam I fitted a SR1 Magneto but that was for a personal need to spend money and most likely won't have provided any performance improvement.
It goes really well and most notable is the improved response to the throttle at speed. I've recently fitted an aluminium barrel because the limitation of the cooling with an iron barrel meant that I couldn't use the top speeds for any length of time without overheating. The only limitation now is the clutch which needs upgrading to cope with the extra performance and of course the brakes which are painted on!

[PeteF]

Thanks Guys, just what I wanted to hear. Next winter I think.

[Geoffers]

Hi Simon,
Were you able to form an opinion as to how much difference the new cams made? I might still be tempted.....
Cheers,
Geoffers.

[simon]

I can't I'm afraid as I did all the mods at the same time and had never ridden the bike in standard fettle. I can definitely see a considerable improvement in performance over my brothers standard bullet but how much of this can be put down to the cams I can't say. I'd like to know though so if you do an A B test please post the finding on the site. S:)