penton Posted November 6, 2007 Report Share Posted November 6, 2007 Can I make a 1961 cub 250cc? Can I use the round barrel? Whitch sleve do I use? Whitch piston? Is a 1961 motor strong enough for a 9:1 piston? Thanks in advance from Sweden Quote Link to comment Share on other sites More sharing options...
trialsrfun Posted November 7, 2007 Report Share Posted November 7, 2007 Hi Penton, I presume your motor has the round barrel & distributor ignition system, for advice on all things Cub the best people to speak to would be either Serco or Alan Whitton. Many people seem to prefer a 230cc Cub rather than the full 250cc motor because 230cc seems smoother to ride, my own bike is 199cc, low compression piston, R cam, PVL ignition & Del-Orto carb this set-up gives plenty of power & I am no lightweight but it really goes well enough for everywhere i have ridden. PM me if you require the phone numbers for Serco or Alan. Quote Link to comment Share on other sites More sharing options...
subira Posted November 7, 2007 Report Share Posted November 7, 2007 I believe that both the 230 or 250 routes need a new alloy barrel. Then the crankcase mouth needs machining to accomodate the larger liner. I'm not sure if the new 250 crank needs roller bearings - 230 uses your existing crank. I have the same set up as TRF and agree that it seems to work reasonably well. If you do the conversion you'll want a PVL fitting, and so maybe it would be best to start with some later cases. Quote Link to comment Share on other sites More sharing options...
penton Posted November 7, 2007 Author Report Share Posted November 7, 2007 Hi Penton,I presume your motor has the round barrel & distributor ignition system, for advice on all things Cub the best people to speak to would be either Serco or Alan Whitton. Many people seem to prefer a 230cc Cub rather than the full 250cc motor because 230cc seems smoother to ride, my own bike is 199cc, low compression piston, R cam, PVL ignition & Del-Orto carb this set-up gives plenty of power & I am no lightweight but it really goes well enough for everywhere i have ridden. PM me if you require the phone numbers for Serco or Alan. Thanks for the answer. I have just bought the Cub (non running) and my trialfriends says that 199cc is not strong enough. Maybee i chould try it for one sesong first. I have Doyer Bransden, R-cam and 7;1 piston and Kehein carburettor. I had not try it in sections yet. So far i have drive my TLR250. If I find it to weak I start with some later cases as Subira told me, but I like to do it myself as I have the machines. Quote Link to comment Share on other sites More sharing options...
vinnied Posted November 8, 2007 Report Share Posted November 8, 2007 Hi Penton,I presume your motor has the round barrel & distributor ignition system, for advice on all things Cub the best people to speak to would be either Serco or Alan Whitton. Many people seem to prefer a 230cc Cub rather than the full 250cc motor because 230cc seems smoother to ride, my own bike is 199cc, low compression piston, R cam, PVL ignition & Del-Orto carb this set-up gives plenty of power & I am no lightweight but it really goes well enough for everywhere i have ridden. PM me if you require the phone numbers for Serco or Alan. Thanks for the answer. I have just bought the Cub (non running) and my trialfriends says that 199cc is not strong enough. Maybee i chould try it for one sesong first. I have Doyer Bransden, R-cam and 7;1 piston and Kehein carburettor. I had not try it in sections yet. So far i have drive my TLR250. If I find it to weak I start with some later cases as Subira told me, but I like to do it myself as I have the machines. I have a 199cc Cub never had a problem with power in normal pre65 trials (im 15 & a Half Stone) Vinnie Quote Link to comment Share on other sites More sharing options...
totalshell Posted November 19, 2007 Report Share Posted November 19, 2007 199 cub never a problem with power shortage for this 16 stone lump, climbs owt i point it at and grips for fun (being big boned finally counts for something...) Quote Link to comment Share on other sites More sharing options...
andy0101 Posted December 6, 2007 Report Share Posted December 6, 2007 Hi Penton,I presume your motor has the round barrel & distributor ignition system, for advice on all things Cub the best people to speak to would be either Serco or Alan Whitton. Many people seem to prefer a 230cc Cub rather than the full 250cc motor because 230cc seems smoother to ride, my own bike is 199cc, low compression piston, R cam, PVL ignition & Del-Orto carb this set-up gives plenty of power & I am no lightweight but it really goes well enough for everywhere i have ridden. PM me if you require the phone numbers for Serco or Alan. hi there im planning on fitting a dellorto carb to my cub ,what size have you gone for and what jets are in it please Quote Link to comment Share on other sites More sharing options...
subira Posted December 8, 2007 Report Share Posted December 8, 2007 22mm PHBL I need to check the jets etc. tomorrow Quote Link to comment Share on other sites More sharing options...
vinnied Posted December 11, 2007 Report Share Posted December 11, 2007 low compression piston, What compression is it Vinnie Quote Link to comment Share on other sites More sharing options...
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