This is a serious problem

GoldenMotor.com

Hzryder

New Member
May 16, 2021
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So I recently rebuilt my top end and it runs perfect it has plenty of oil and everything else is fine but when I ride anywhere from 100 to 200 feet it acts like it’s about to lock up (it actually does sometimes) then It randomly works again for another 5 minutes I don’t pin it I don’t beat it I simply try to cruise it but it just try’s to lock up and it runs beautifully when I first start it then it starts ticking and it runs nice with idle but the ticking is really loud but when I ride it there’s no tick until it try’s to lock up I keep pulling off the jug and everything is fine there’s a normal amount of play in the crank and It spins fine nothing has ever fallen into the crank my gears are fine and the bearings are fine so what the **** is causing this
 

Larry Trotter

Well-Known Member
Nov 26, 2017
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I think Jerry has it right. If it only ticks and tries to lock up when you are moving and the engine idles ok then it’s likely unrelated to the top end rebuild. Hope you find the problem and tell us what it was. I would probably get it started and get the back wheel off the ground and watch what is going on when it’s clicking.
 

Hzryder

New Member
May 16, 2021
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The chain is well lubed and perfect slack and the bike has double kickstand so the wheel hovers over the ground it spins fine it’s definitely not the wheel that’s ticking if I have it running at idle and I give it a rev or two it starts ticking it’s a 1 peice Jug and I’m just really confused also there isn’t any play or wobble in the wheel I’ve had it rebuilt with plenty of grease and the wheels only about maybe 1 month old also I forgot to mention the loss of power before it tries to lock up and the fact it kills immediately when I pull in the clutch
 

Larry Trotter

Well-Known Member
Nov 26, 2017
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Then I would look closely to see if you have a crack in the cylinder. Lots of times people mistake a blown head gasket for a mechanical click. I know you don’t have a head gasket but a crack will have the same effect.
 

Hzryder

New Member
May 16, 2021
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Right as there out of stock well that’s just my luck thank you for the help also if I can’t find the crack or if there’s isn’t even one what should I do
 

Larry Trotter

Well-Known Member
Nov 26, 2017
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Someone here probably knows if you can just swap in a cylinder with a head and jus add studs for it.
 

Hzryder

New Member
May 16, 2021
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The sad thing is I have the 100cc not the yd100 the bt100 and you can find jack squat for these motors I got lucky being able to buy a rebuild kit from Australia and had it freight shipped to me I’ve looked for a two piece design and no luck
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
7,338
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Los Angeles, CA.
Are you sure the engine is actually 'locking up'???? (or is the engine slowly losing power until it simply turns off)?

Could it be that the fuel isn't flowing to the carb fast enough? (gas cap not venting)?
Could the spark plug be fouling with oil from simply 'cruising' & not getting hot enough to burn clean ?? (too much oil in gas)?
 

Hzryder

New Member
May 16, 2021
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Update: so I took the top end off and when I pull the piston rod and roll the crank in the case every turn it makes a little knock but stops when I pull it faster the cylinders fine I have a boatload of pistons the compression is strangely high I haven’t started it to see if it still knocks because I don’t have a carb but I have checks the rim that’s all good the case bearings are good the clutch is fine so I’m at a loss
 

Hzryder

New Member
May 16, 2021
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And yes I’m absolutely sure it’s locking up because it loses all throttle and bogs then it’ll work for a second then you’ll feel like your holding the coaster brake trying to give it throttle then I pull in the clutch it dies then I’ll be rolling let the clutch out and it’ll start again
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
7,338
1,991
113
Los Angeles, CA.
I think your gas tank isn't venting properly
When a engine 'locks up', it stays locked up (& won't re-start)

Another thing you might check... make sure your choke lever is down.
 

Hzryder

New Member
May 16, 2021
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Locks up to the point where the back wheel won’t move when I try to see if there’s compression and it’s tight but it still manages to free up
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
7,338
1,991
113
Los Angeles, CA.
I still think your problem is something other than the engine locking up...
I'm sure if you can find someone in your area with experience in these bikes; they can quickly find your problem for you.... good luck!
 

Larry Trotter

Well-Known Member
Nov 26, 2017
476
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Update: so I took the top end off and when I pull the piston rod and roll the crank in the case every turn it makes a little knock but stops when I pull it faster the cylinders fine I have a boatload of pistons the compression is strangely high I haven’t started it to see if it still knocks because I don’t have a carb but I have checks the rim that’s all good the case bearings are good the clutch is fine so I’m at a loss
 

Larry Trotter

Well-Known Member
Nov 26, 2017
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Have you taken a real close look at the gear reduction on the right side? Since you had to do a rebuild on the top end I assume you have quite a few miles on it.