timing chain

[jpman]

can someone recommend a tining chain that will last a while? Mine has stretched so much that it needs a master link just to keep it the right length.

[ckau]

never heard of a timing chain streching. Is it loose enough to jump teeth on the cam? if you have removed the head ,you may not have got the chain back in it's proper position in the guides or the chain was not positioned on the lower crank gear correctly. Normally the chain tensioner can account for any sort of stretch. Check the tensioner to insure it is extending correctly. Facing the motor from the rear, on the left of the carb ,there is a unit bolted down to the lower case with two bolts and a cap between them. This is the can chain tensioner. remove the cap. look down inside, you will see a slotted screw head. turn the screw clockwise until it stops. This pulls a spring loaded plunger back off the timing chain,locking it up, relaxing tension. Turning the screw counter clockwise unlocks the plunger allowing the plunger to extend, putting pressure back on the chain. You can remove the tensioner by unbolting the two bolts and pulling it up out of the case. while it is out inspect it and turn the screw to insure it retracts and extends freely. lock the plunger up before removing it and don't forget to unlock it after re- installing. I have made this mistake before and got my cam timing all screwed up!

[kliff]

The only time I've seen one stretch, is when the tensioner has been removed, and re-installed without resetting it to zero tension, as it is tightenned down.

This usually requires a new chain and tensioner rails....otherwise, that chain is going to break....

[chuckorlando]

I've had my tensioner off at least a dozen times and I never relieve the tension. I simply take out the 2 bolts. I run a rally hot motor that pushes over 10,000 rpm and never a problem.

[jpman]

My chain is stretched, the tensioner is maxed out and sliders are in place. If I turn the engine over by hand, the chain jumps several teeth on the cam gear. I was wondering if I could find a "Honda" chain with the correct number of links. Looking insde the motor the chain has a huge amount of slack in it.

[kliff]

Originally Posted by chuckorlando

I've had my tensioner off at least a dozen times and I never relieve the tension. I simply take out the 2 bolts. I run a rally hot motor that pushes over 10,000 rpm and never a problem.

Then you are extremly lucky Chuck. I've rebuilt a dozen due to the owners not re-setting them. But if you've never reset, then it has already down all the damage it can do, and isn't doing any further tensioning, as it is already at full extension. Enjoy it, and just don't be surprised when it does go pop.

[chuckorlando]

I dont see how. It aint putting any more pressure on the chain. That spring puts out x amount of tension and that dont change. Once you relieve the tension with the flat head screw it is utting out the same amount of force. I'm not saying your wrong, I just dont see how.

[kliff]

The tensioner extends due to the spring pressure, true. But it has an internal cam type deal, that prevents it's retraction, unless done manually, as descibed above. So when you remove it, the spring pushes it out to full extension. And if installed without releiving it, damage is done. Sometimes more readily seen immediately, sometimes not, if the engine has enough time on it to have already stretched the chain considerably, and or, worn the guides.

All I'm saying, is yours is parobably maxxed out, and not capable of any further adjusting, so as wear piles up, and future stretching occurs, there will be nothing left to compensate.

[chuckorlando]

Actualy mine can be compressed without the screw. You just push down on it and the screw turns as you apply pressure. Maybe thats why. My dads is the same way. His Kinroad will compress without turning the screw. Dont know if they should do that but they've been run very very hard and aint had a problem. My chains are tight enough that you have to take off the rocker arms and lean the cam to get it off. Same as my dads. If it's stretched I would hate to see one thats not

[kliff]

Originally Posted by chuckorlando

Actualy mine can be compressed without the screw. You just push down on it and the screw turns as you apply pressure. Maybe thats why. My dads is the same way. His Kinroad will compress without turning the screw. Dont know if they should do that but they've been run very very hard and aint had a problem. My chains are tight enough that you have to take off the rocker arms and lean the cam to get it off. Same as my dads. If it's stretched I would hate to see one thats not

If you can compress it, with out the screw driver method, then the internal cam lock is broken, from installation, without relief.
If you were to replace it with a new unit, and install relieved, you could actually see a little more ooooomph, due to a more accurate cam timing throughout the rpm band. Though with these small engines, even at 180cc, it may be such a miniscule difference, you'd never notice it. Luckily, you broke the cheap and easy part, I've seen non-relieved installations, take out an entire engine.

Luck o the draw....cool beans!

[chuckorlando]

It came new like this thats why I asumed thats how they all were. My old one was messed up on the motor when I bought it and would'nt compress enough to put it on the new motor.

[kliff]

LOL....that ain't surprising either. I fixed 3 brand new scooter GY6's a while back, all the same brand, they "knocked" when the owners first tried to start them, then had no compression.

The pistons were in upside down, so the incorrect valve releifs lined up with the valves, and NONE of the valves had any clearance....ell zippo, nada, nyet.... so when they rolled over the first time, each engine bent the intake valve. 3 in a row.....now that's QA, huh? But I fixed 'em, and the dealer replaced my stock of intake valves and head gaskets, the owners all merrily road away.....

Chinese scooters and engines, a never ending adventure.LMAO! Did I mention the one that came through with no rings...

[BuggyMaster]

gotta agree with kliff on this one, you should not be able to compress that thing by hand so to speak. I have never seen a chain stretch that bad either. Very rare to say the least since the tensioner can usually take care of that.

[ckau]

Originally Posted by jpman

My chain is stretched, the tensioner is maxed out and sliders are in place. If I turn the engine over by hand, the chain jumps several teeth on the cam gear. I was wondering if I could find a "Honda" chain with the correct number of links. Looking insde the motor the chain has a huge amount of slack in it.

check to see if the chain has fallen off the crank gear. if it has dropped between the gear and the inner case, the chain feels like it is correct but it will have the slack you describe.

[BuggyMaster]

good point. That would definately act like that.