HELP - '86 TRX 70 Smoking!!

[MikEXtreme]

Just bought my daughter an '86 TRX 70. It runs pretty good but it smokes like a chimminy. The smoke is white and continues to smoke after its warmed up. Please advise.

THanks.:confused: :confused:

[redrider37]

I'd just make sure the exhaust isn't plugged up, other than that just throw in a new set of rings and gaskets.

[kenny]

you may want to do a leak down test.you can buy the tool at a parts store.im thinking the trx is 4 stroke. also you may want to check compression (170 psi xr 75) if you do not want to do this just keep riding.poss ck to see if spark plug is oil fouling.

[MikEXtreme]

I took the carb off and it was nasty, all kinds of dirt. I am in the process of puting it back together.

[Colby@C&DRacing]

you need to freshen up the top end. It is burning oil. THe valve seals should also be replaced.

[MikEXtreme]

I went to Chaparall and ordered new rings. The guy at the parts counter told me if I was going to put new rings that I would also need a new piston. I wasn't sure if this was right, so I went ahead and ordered what he suggested.

With a new piston do I need to have the cylinder honed? Or would it be ok to install the new parts?

While its apart should I replace the valves as well?

Any help or suggestions would be useful!:p

[JabberJaw]

Originally posted by MikEXtreme
continues to smoke after its warmed up. Please advise.

THanks.:confused: :confused:

This happens to me right after I score!

[MikEXtreme]

bump

[redrider37]

You don't necessarily need a new piston but it won't hurt to throw one in and the price difference isn't that great. I own and collect several honda ct-70's and it only costs about $45.00 for piston,rings,and gasket set which includes new valve seals. The seals I highly recommend you put in and then lap the valves back in with a valve grionding compound so they dont leak.As far as honing the cylinder,that is fine if there is no scores in the cylinder.If there is scores then it will have to bored out.

[MikEXtreme]

Originally posted by redrider37
You don't necessarily need a new piston but it won't hurt to throw one in and the price difference isn't that great. I own and collect several honda ct-70's and it only costs about $45.00 for piston,rings,and gasket set which includes new valve seals. The seals I highly recommend you put in and then lap the valves back in with a valve grionding compound so they dont leak.As far as honing the cylinder,that is fine if there is no scores in the cylinder.If there is scores then it will have to bored out.

Redrider- Thanks for the information. What do you mean by "lap the valves back in with a valve grinding compound. If there are scores and it needs to be bored out will I need a different piston than the stock one I purchased?

thanks for you help!

[redrider37]

Mike-Yes if the cylinder needs to be bored you will need a oversize piston,but only if it is scratched up to where the hone job won't clean it up. As for lapping the valves you get a lapping compound from auto parts store,and a suction (stick) to spin the valve into the compound.This seats the valve back into the head so it doesn't leak.However you will need a valve spring compressor to get the valves out.If you do not have the tools I suggest just taking the head to the dealer as it will probaly cost you the same or more to buy the compressor.

[MikEXtreme]

Originally posted by redrider37
Mike-Yes if the cylinder needs to be bored you will need a oversize piston,but only if it is scratched up to where the hone job won't clean it up. As for lapping the valves you get a lapping compound from auto parts store,and a suction (stick) to spin the valve into the compound.This seats the valve back into the head so it doesn't leak.However you will need a valve spring compressor to get the valves out.If you do not have the tools I suggest just taking the head to the dealer as it will probaly cost you the same or more to buy the compressor.

Any machine shop can hone the head?

Thanks for the info!!

[redrider37]

Yes any machine shop or your local dealer could hone out your CYLINDER and then I'd ask for a price to lap the valves in the head.

[MikEXtreme]

Thanks for the info......:) :) :) Do you know what I can do to clean the exhaust pipe? The inside has to be nasty!

[redrider37]

Basically just take the baffle out of the end and blow compressed air into it.Anything left should just burn out.