has anyone here honed a china jug. my jug has a few scratches that i can just feel with my nail and piston has some wear too but i think just few wipes with fine sand paper will do it. oh and when my piston is on the con rod it has a little movement when i rotate it sideways but it doesnt have slak when moving up and down.
honing a cylinder
- Thread starter talbotti
- Start date
I wouldn't recommend doing that. The cylinder is chrome plated and a very thin layer. Getting too aggresive with a stone will remove the chrome and...well. That wouldn't be good. You'd then have steel rings against aluminum.
Tom
Tom
I'm assuming we're talking about a 2 stroke, HT or Chinese engine here.
Very fine scratches in the cylinder wall probably won't effect compression that bad. Gouges and deep scratches are something else. That could be a sign of a broken piston ring or that something has been injested into the engine, possible carbon or trash that could have been inside from the factory.
The slight rotation of the piston on the rod is a sign of wear. Eventually you'll be replacing some parts. That said keep in mind that these little Chinese engines are not known for manufacturing perfection and some slop and poor fit is expected.
If the engine is running good, not terribly noisy (knocking, rattling) then I'd say run it. If you just like to tinker and want to play with it, replace the parts that are showing signs of wear and extend your riding enjoyment.
I should have asked this earlier but, how many miles do you have on this engine and what oil/fuel ratio are you running? What oil are you using? Do you do a lot of high speed riding?
Tom
Very fine scratches in the cylinder wall probably won't effect compression that bad. Gouges and deep scratches are something else. That could be a sign of a broken piston ring or that something has been injested into the engine, possible carbon or trash that could have been inside from the factory.
The slight rotation of the piston on the rod is a sign of wear. Eventually you'll be replacing some parts. That said keep in mind that these little Chinese engines are not known for manufacturing perfection and some slop and poor fit is expected.
If the engine is running good, not terribly noisy (knocking, rattling) then I'd say run it. If you just like to tinker and want to play with it, replace the parts that are showing signs of wear and extend your riding enjoyment.
I should have asked this earlier but, how many miles do you have on this engine and what oil/fuel ratio are you running? What oil are you using? Do you do a lot of high speed riding?
Tom
yeah the engine runs fine and it dont have many miles because i assembled it last summer and in my country police wont like equipment like this. i think thoes little marks got there because i had a intake leak and it ran little lean. oh yeah and i run oil fuel mix about 1 to 25
Honing by hand is a tricky operation at best. Especially if you want the crosshatch to be proper. Usually 60 degrees. It took me many hours of practice before i got it right. Chances are you would destroy the cylinder before you got it right. Unless you have done it before. So to repeat what has already been said, run it until you can't anymore. and have fun doing it.
Has anyone thought of installing a custom steel liner, you may have to bore out the cly. but then you can hone and re hone it.
I know the barrel and piston is not that much, but it might make longevity much better.
Just a thought in time.
I know the barrel and piston is not that much, but it might make longevity much better.
Just a thought in time.
over $100 closer to $200 to have a jug sleeved and its a ported jug on the ht motor so that may increase the cost. If it could be done but the walls of the cylinder are to thin to be bored out enough to even be sleevedHas anyone thought of installing a custom steel liner, you may have to bore out the cly. but then you can hone and re hone it.
I know the barrel and piston is not that much, but it might make longevity much better.
Just a thought in time.
It could be possible if say, you were to take a 66CC jug, bore it out the most possible and then sleeve it for a 48CC or smaller engine.
The hardest part would be indexing the sleeve, because like Yank said, it's got ports.
The hardest part would be indexing the sleeve, because like Yank said, it's got ports.
heres a motor with sleeve he says in the video steel but i think its iron.
dunno if all motovelo motors has sleevs.
http://www.youtube.com/watch?v=vGLpy5SP8LA
dunno if all motovelo motors has sleevs.
http://www.youtube.com/watch?v=vGLpy5SP8LA
Iron hands-down is the only material to use for a sleeve. It holds a crosshatch the best and rings will seat better against it.
edit: biknut, if a proper iron-lined jug were available, it would last a long time. No need to replace it often, although I agree with you, it's usually less headache to do a simple R&R
edit: biknut, if a proper iron-lined jug were available, it would last a long time. No need to replace it often, although I agree with you, it's usually less headache to do a simple R&R
I have tried to rebuild two cylinders, and neither one worked. you can spend $50-60 on a rebuild kit that may or may not work due to too much play in the crank arm, just more than slightly worn bearings, bad seal, whatever. Or, you could look on ebay and probably find a brand new engine for $90 or so. I say run it till it dies, then replace the whole engine. replacing a cylinder on these engines is like replacing a head gasket on a car. replacing that one part might seem easy, but you could find a whole slew of other problems along the way. buy a newer car, you know it at least run when you drive it off the lot. buy a new ht engine, it should at least run out of the box. the amount of money you could lose on a rebuild kit versus what you pay for a replacement engine, its not worth a gamble.
You are right, it would not pay to try and save a bad or worn cylinder, sense they are chrome plated and very hard to recondition, just buy a new one, The only thing I was saying it would be nice if the liners were cast iron then it would be feasible to do it.
I saw on you tube a new engine that had a iron cylinder, so maybe china is listening to to the needs of there customers.
I saw on you tube a new engine that had a iron cylinder, so maybe china is listening to to the needs of there customers.
If I recall correctly (yeah right!) most all of the 48cc engines from years ago had cast iron liners. The 55cc and larger never had it.I saw on you tube a new engine that had a iron cylinder, so maybe china is listening to to the needs of there customers.
Chrome linings is very hard and would not lend itself to honing out very well, plus it is a thin layer, which transfer's heat good, not to mention the lighter wight.
But if a thin stainless steel liner could be used and molly type rings used to allow the rings to seat, than it would be a long lasting setup.
But then the cost to replace would be high, so that's why the manufacturer use's a chrome lining I believe. But the new cast iron liner seems interesting, as long as it could be retrofitted to the older engines when time came to replace.
I remember the race type big block Chevy. engine used silicone in the alum. block. the pistons and rings just rode on that, I also remember the vaga motors were the same setup.
So there are a lot of ways to do things, but in the case of the china motor, the cost factor outweighs a lot of options, so the parts can be low cost.
But if a thin stainless steel liner could be used and molly type rings used to allow the rings to seat, than it would be a long lasting setup.
But then the cost to replace would be high, so that's why the manufacturer use's a chrome lining I believe. But the new cast iron liner seems interesting, as long as it could be retrofitted to the older engines when time came to replace.
I remember the race type big block Chevy. engine used silicone in the alum. block. the pistons and rings just rode on that, I also remember the vaga motors were the same setup.
So there are a lot of ways to do things, but in the case of the china motor, the cost factor outweighs a lot of options, so the parts can be low cost.
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