I just finished repairing a 98' with the failed CCT on the front cylinder. The piston just had 2 very small nicks from valve collision. I de-burred and cleaned them up and put it all together. Just got it running last night and all seems good.

So my question is, how often have pistons been damaged beyond usability with a CCT failure? I am thinking of doing another one that is for sale locally with a bad CCT. But did I just get lucky this time? Or is it more common to be able to re-use the piston?
Thanks for any info...Ty

 

It would depend on the RPM the timing hopped at. If there's massive piston damage I can assure you, you'll be buying a head as well.

 

Yea, I bought a used head for this one instead of the cost of completely rebuilding the existing one. I guess that would be another good question. Do most failures happen at idle or low speeds? I know the Toyota 22RE chains I have repaired seem to always break at or near idle.
If I have to tear in to replacing a piston, it would not be as financially practical to do another one of these. Trying to possibly make a little profit on one and keep the other!
Thanks for the reply!

 

I'd imagine closer to idle/lower rpm as there will be more of a jerking motion on the chain. The chain should remain pretty taught at higher rpm's.

 

Having rebuilt several of these following cct failure, they rarely damage the piston. You'd have to be quite unlucky to buy one where the valve head had snapped off.

If that's what you found on stripping it, you'd have the choice of fitting a secondhand motor or splitting it for parts.

Although fitting a replacement head seems a good idea, you might overlook the possibility of damage to the big end shells due to the extreme pressure of trying to force an immovable object (head) with an irresistable force (piston pushing broken-off valve head).

It could also twist the crankshaft.

But as long as you're not paying much for the bike as a non-runner, it's definitely worth picking these up.

I've done two this year, as well as repairing other people's bikes.
Just not much time to do more to mine

 

I will have to agree with VTaRse. I have also repaired several of them this year. I have never had an issue with pistons on any I have repaired. Just remember to replace the chain on the cyl that jumped time. When the tensioner fails, it tends to stretch the chain. Just my 2 cents worth......

 

Thanks for the additional replies. I got this first one cheap enough that either way (fixing or parting) I would come out good. I did notice the timing chain must have stretched as the timing marks on the cams come up a degree or 2 off. I think it will be fine for now.
It runs real good. Now I just need it to stop raining long enough to try it out!
My hope is maybe picking up this other local one cheap enough that I can fix it and sell one of them this spring. Then maybe I can afford to keep one!

 

My front cct just went out. It started ticking when I was going about 30 so I shut it down right away and pushed it a few blocks home. Im positive no damage was done as I started it up for a second and it runs fine, just ticks loudly. I think its all random on how much damage is done. I seem to be getting the brunt of all the **** that goes bad though. My r/r went out, it fried my battery, my side stand switch went out, and now the cct all in a week.