LT80 Trouble... no power
#11
02-18-2018, 10:38 PM
Advance/autozone will lend you a comp gauge.
From what you describe, I think one or both of the china rings are upside down.
I shave the heads .030 because it bumps the compression up enough to get it to a more efficient range. It just runs better. Shaving your head will bump it up but is not the problem.
The heads don't warp. At least I haven't seen one warp yet in 25 years. Using the old head is good imo.
I have a fresh bored stock cylinder here. Wanna try it? You pay shipping. If it fixes it you can buy it or send it back.
From what you describe, I think one or both of the china rings are upside down.
I shave the heads .030 because it bumps the compression up enough to get it to a more efficient range. It just runs better. Shaving your head will bump it up but is not the problem.
The heads don't warp. At least I haven't seen one warp yet in 25 years. Using the old head is good imo.
I have a fresh bored stock cylinder here. Wanna try it? You pay shipping. If it fixes it you can buy it or send it back.
#12
02-19-2018, 05:21 AM
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Ok, thank you, I just may do that. I already have another seal on the way to change the mag side, and I will double check the reeds/reed cage this week. Also will get ahold of another compression tester and try that. It's just weird that both the new and original top end give the same 50psi compression reading.
If I end up buying your bored cylinder, do you have a shaved head to go with it? I will also send you all my original top end as a core.
If I end up buying your bored cylinder, do you have a shaved head to go with it? I will also send you all my original top end as a core.
#13
02-27-2018, 04:41 PM
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Ok, another update.
First off, the compression tester I was using was defective. It wouldn't go above 50psi. I got another one and tested it with the original piston and cylinder...80psi. I rebuilt the top end again with the new eBay piston, cylinder, head gasket, new base gasket, double checked the rings and made sure the tapered side was up. Tightened the head to spec. Compression tested with a squirt of oil...125psi.
Now, got it back together enough to run it, put it on a stand and broke it in. Revs up fine on a stand. Once on the ground, it's the same thing...no power under a load. It seems to want to move if I ride it downhill, once it revs up enough it seems to want to go. But from a standstill, it has no power to move itself, just keeps bogging. If I pull the choke and try to hit the throttle, it seems a little stronger, but still won't move. I took the carb/aircleaner elbow off and hit the throttle, no difference. I did notice at idle it spits/mists gas out the front of the carb. Plenty of fuel getting to the carb. If I remove the fuel line and run it into a can and turn the petcock on, it has a steady stream of fuel. The carb needle is set on the second notch from the top.
So what next? What do I need to do now? Please, any help is appreciated...this thing is gunna drive me to drink. Lol
First off, the compression tester I was using was defective. It wouldn't go above 50psi. I got another one and tested it with the original piston and cylinder...80psi. I rebuilt the top end again with the new eBay piston, cylinder, head gasket, new base gasket, double checked the rings and made sure the tapered side was up. Tightened the head to spec. Compression tested with a squirt of oil...125psi.
Now, got it back together enough to run it, put it on a stand and broke it in. Revs up fine on a stand. Once on the ground, it's the same thing...no power under a load. It seems to want to move if I ride it downhill, once it revs up enough it seems to want to go. But from a standstill, it has no power to move itself, just keeps bogging. If I pull the choke and try to hit the throttle, it seems a little stronger, but still won't move. I took the carb/aircleaner elbow off and hit the throttle, no difference. I did notice at idle it spits/mists gas out the front of the carb. Plenty of fuel getting to the carb. If I remove the fuel line and run it into a can and turn the petcock on, it has a steady stream of fuel. The carb needle is set on the second notch from the top.
So what next? What do I need to do now? Please, any help is appreciated...this thing is gunna drive me to drink. Lol
#14
03-06-2018, 05:48 PM
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#15
03-07-2018, 08:39 AM
#16
03-07-2018, 08:44 PM
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#17
03-08-2018, 11:22 AM
Make sure the washer under the primary screw that holds it onto the crank is facing the right way. If that checks out run it with rear tires of the ground and make sure it looks like it's shifting out ok. You mentioned you cleaned the secondary and it moves freely, but did you check the shoe material? It may not be grabbing hard enough to get it rolling initially. Next, I'd confirm your gearing (front/rear sprockets) and make sure that it's not ridiculously tall...
Does the quad roll freely when you push it...maybe something else is binding...
In stock form these are torque monsters...so getting it moving shouldn't be an issue at all with a fresh motor and clutch-work...
Does the quad roll freely when you push it...maybe something else is binding...
In stock form these are torque monsters...so getting it moving shouldn't be an issue at all with a fresh motor and clutch-work...
#18
03-08-2018, 12:56 PM
Let's talk about that ebay carb. Is it one with the air screw? I'm not a fan of those. >>> NM, I just seen you tried the OEM carb.
Stupid question but you did put the reeds on big one first? Are they seating (flat)?
When on the ground and side cover off, look to see if the belt is going down in the rear clutch too fast.
Stupid question but you did put the reeds on big one first? Are they seating (flat)?
When on the ground and side cover off, look to see if the belt is going down in the rear clutch too fast.
#19
03-11-2018, 01:11 PM
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#20
03-11-2018, 02:36 PM