GB 500 TT

[guest1711]

Hi guys newbie here ,  I'm an old person had allsorts of thumpers Velocette venom clubman,MZ scorpion, Honda XBRs x2 Honda GB 500 TTs x3 I keep thinking I'm better and then go and buy another single and up to now they have all been really good . This time out I seem to have got a little giddy and bought a GB TT which consumes oil at an alarming rate,it is cosmetically ok and I gave £1800  for it. It probably needs a rebore /valve stem oil seals has anyone any experience of reboring an XBR/GB TT, any info greatly appreciated.......

[guest564]

I've rebuilt a few XBR engines. They aren't difficult to work with there is a knack to getting the camchain adjuster back in using a big screwdriver. On the XBR the head and barrel can be removed with the engine in situ.

[guest1711]

Thanks for the reply, can anyone recommend aftermarket pistons and reborers in lancs or anywhere.
I looked at the clocks and they showed 25k miles it was only when I returned home and studied the mot that I noticed the clocks had been changed and the proper mileage was 65k eek.
The rest of the bike is very good so caveat emptor.......

[guest295]

Check for stuck rings. If the bike was left sitting for a long period, or 'warmed up' by leaving it idling from cold, the rings may have become glued to the piston. Sometimes you can free them up by replacing the oil with 'turbinol' or similar and giving it hell briefly, then replacing the oil, but otherwise it's a top-end job. David Silver's probably got the bits.

[guest987]

Regrettably there people out there tarting up really ropey GB500's and they end up biting real enthusiasts, leaving a sour taste.
There is a tuning shop down south who may be able to assist but for the life of me I cannot remember their name Sorry.

rob

[guest7]

I've got a 160,000 mile XBR that used to haul a sidecar (see picture on the left). It doesn't use much oil and by god I've thrashed it. Has your bike been stood? and how many miles have you done since purchase? I suspect that a top end strip down will only reveal something dumb like a stuck ring.

To be fair I haven't seen increased oil use as an issue with heavily used XBRs or GBs. However, I don't have much experience of what can happen to stood engines, do seals, etc. back off or harden? (I know at least 80% of you on here are more tehcnically literate than me so I expect an answer pronto).

Mind you I keep forgetting that nearly all XBRs and GBs are over 25 years old... it's scary, especially as I bought one new   

GC