just bought a really battered thundercat

Hi guys!

Just joined the forums here. I've always loved the thundercat and i ended up buying a really old one from a friend for peanuts. This bike has done over 80k!! Has had loads of parts replaced ver the years but the engine is still original! It goes quite well actually but it does have a few problems.
It leaks oil, alwways a few drops of oil under it in the morning, it accumulates in the pipes under the stump but the engine looks clean although i havent inspected it closely. The engine feels sluggish, i think it doesn't have the full thudercat power. Also, there is a rattling sound on low revs but only when the bike is moving. it sounds fine in neutral. the noise is probably always there, but its more noticeable in low revs. Also i notive the clutch lever needs adjsuting, i wonder if this is related to the noise. Also, the rear shock is rusty.

apart from this the bike is fine (lol). No 2nd gear issues, good forks, spotless panels and tank. brand new tires etc. Idles fine, starts first time, no smoke at all.

I can do most of the restauration when it comes to rust and easy to fit parts. I'm worried about the engine.
Is there a point in going in a changing seals and doing maintenance on this battered engine? Or should i just replace the engine? How much is a new engine likely to cost, fitted?

At the end of the day, i love the bike, i got it cheap and if i spend a grand or so on top and end up w a good bike ill be happy and ill learn a lot about it.

what do you think?

thanks

Hi and welcome, sounds like a good buy. I am sure mine is just as old and is close to yours in miles.

The noise could be a seized chain link or worn chain / sprockets. take off the cover over the front sprocket, there might well be a lot of gunge in there and could be the source of your oil leak, especially if the chain has been oiled (by hand or a Scottoiler). The clutch mechanism is in there too, it could be clogged up.
Dirty air filter, worn plugs, un-balanced carbs can all rob power.

The original rear shock on there?

-Steve

ok, so even tho the engine has over 80k, it wont necessarily mean its gone? i good overhaul should get it back to life? thats impressive, i mean, the bike passed an mot just before i got it. I must say the milage puts me off the bike and I was leaning towards a new engine really.I'll pass it on to my mechanic and let him assess it.

What about performance wise, what are the best tricks to improve performance
? good air filters, iridium sparks, a sports exhaust, anything else?

I had thought about adding a +1 rear sprocket to give it more kick in town and maybe raise the rear. Anyone here done this before?

Thanks

Out of balance carbs can give rise to noises that sound almost mechanical, so check them over and perhaps get them balanced

Hi & welcome to the gang. Like steve said a past its best chain can cause strange noises also check are the plugs tight? does it have enough oil? when was it last changed? generally have a good check over everything. Good luck getting it sorted. Paul.

80K shouldn't be a problem as long as it hasn't been hammered too much, should be good for double that. Your mechanic can tell you the condition, maybe have a compression test done too.

andre666 wrote:
What about performance wise, what are the best tricks to improve performance
? good air filters, iridium sparks, a sports exhaust, anything else?

I have a K&N; did make a small difference as did the exhaust, but I'd just as easily to go back to the original can. For me the best performance mod I have done is embark on 'Skills for life'

thank you all for your replies