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T 25 Project

Posted: Fri Jun 12, 2020 11:44 pm
by Langster
Here is my project bike, a numbers matching T25 SS. From the serial number it appears to have been made in November 1970 (letters PE).

A barn find,it was last on the road one only knows. The bike is largely complete (with side panels) except for the electrics and instruments. Not much rust at all, no doubt due to the thick protective layer of grime. The motor doesn't turn over. Its already off the bike and on the bench for dismantling.

I'm looking to swap out the 250 for a B50 engine, switch the SLS front brake to TLS, update the electrics and cosmetic improvements.

Re: T 25 Project

Posted: Sat Jun 13, 2020 5:59 pm
by midgie
Looks a great little project, correct with the date code Nov 70.

Re: T 25 Project

Posted: Sat Jun 13, 2020 8:49 pm
by beat
Hmmmm <201

needs a bit a clean I guess.... <212

Re: T 25 Project

Posted: Sat Jun 13, 2020 10:55 pm
by Langster
So I started dismantling today and took the top end off. Piston would not move in the bore so I applied liquid wrench and a little persuasion with a wooden mallet and dowel. Rust in the bore, some grooving. Weld repair to the bottom of the cylinder liner.
Small end bushing seems to have been improperly installed (or did it spin?) - upside down and 2-3 mm off center, blocking oil hole at top of rod. Some overheating of the gudgeon pin going on it seems. Some definite rocking of the piston/gudgeon on the small end bush.
Im guessing it had been bored out. Its written 1.0 mm OS on the top of the piston.

Re: T 25 Project

Posted: Sun Jun 14, 2020 8:08 pm
by beat
some work ( plaisir ) ahead....


Re: T 25 Project

Posted: Mon Jun 15, 2020 11:51 am
by koncretekid
Isn't PE 1971?

Of all the B50 parts I have, they are in Colorado and I can't get there now. I have a set of cases that need a weld repair where the sump passage to the oil pump has been punctured. I won't be there until this fall but I'll keep you in mind.

Other than that, E & V Engineering will have parts which he may be able to courier up to you from Michigan.


Re: T 25 Project

Posted: Tue Jun 16, 2020 1:38 am
by Langster
Hi Tom

November '70 according to the search tool on this site. A '71 model year perhaps.

I'll have a look at EV. I have also contacted Britcycle in Wolfville.


Re: T 25 Project

Posted: Fri Nov 20, 2020 8:12 pm
by Langster
A little update. I stripped the bike, engine down completely.
Didn't want to sand blast the complete frame so i used my grinder with wire brush disk to remove rust from the nasty areas and chemical stripper and wire brush for all the other black and silver bits, mudguards and tank. Tank got a good cleaning with MEK to remove varnish and muriatic acid for the rust, prior to chemical stripped and wire brush.Here are a couple of pics.

No progress on the engine as I hold off for a reasonably priced B50 engine (no luck so far). I may have to revert to plan B - redoing the original 250 cc engine. Will give it another month or two.

Dismantled forks and cleaned them. Chrome had only light pitting which I stoned down. Replaced seals, o-rings and Doughty washers. New Hagons for the back.