Reborn to oversize

[Jono]

I have a 150 Indian barrel that unfortunately the circling came out of the small end pin and scored the barrel.
My question is - is it worth having it bored to 175 and if so what short of cost do you think I am looking at for the complete job . I assume apart from the boring cost I am looking at a new piston and head reprofiling .

Would be interested if anyone can recommend a facility that can carry out the complete conversion including supply of parts and likely cost.
Nono

[Jim Rose]

By the time you've done all of that you may as well buy one of the many complete kits that are out there. Little or no saving in trying to save a standard barrel

[missing lynx]

most good scooter shops will do it for you It should be allot cheaper than a kit and some of the cheaper kits on the market are poorly made and take allot of work to make them perform correctly personally I would buy a 175cc conversion piston (and gaskets) and find a motor engineer in your area to rebore your cylinder for you the rebore should cost £10-£20 a piston would be about £40 remember you need a conversion piston not a std tv 175

[Jono]

Thanks missing Lynx sounds like a viable proposition, what about the cylinder head do I buy a 175cc head?
Jono

[rossclark]

You'd be better to get a 175 head, just opening out the 150 to 63/64 mm isn't enough to get the compression ratios and combustion chamber right.

[missing lynx]

yes a 175 head would be handy as the cost of having a 150 re profiled would probably the same as a new head

[Donnie]

be sure it's a 150 barrel to start with, not a 125 thats already been bored to 150 mate.

[Jim Rose]

The most reliable top end I've had in a long time is one of those "poorly made" 175 kits. I bought it to replace an old iron barrel I was using had worn out and the cost of the kit was only a little more than having my old one bored etc. The plus side was I didn't have to source the parts and run around to engineers etc to get the old one sorted.

I've had the kit about 6-7 years and when all else has failed I know that the 175 engine will get me there. Last year the engine did the Euro and the Derbyshire 150. All i ever did was bolt the kit on when it arrived. From memory it's an AF Alli barrel etc. It also gives me a genuine 65mph

[missing lynx]

you were lucky then I've spent hours sorting out port timing etc on e bay 175 alloy kits for friends to get them to run well once sorted they do run well but unfortunatly it's pot luck if you get a good one or not

[Jim Rose]

As I said got mine from a dealer not e-bay