Lack of power/bursts of power

Also should mention, after the 5 miles I rode (which is currently it's longest trip), there was a bit of smoke coming off of the motor. Could the gasket at the base of cylinder be shot? I used ultra black to seal that one so I doubt it is, but would that cause this issue?
 
It's probably oil from my own hands since I put a few coats of high heat paint on the whole thing. Or at least I hope thats what the smoke was
 
Just took the tops off the acorn nuts and I was no where near bottoming out on them, also put another head gasket on that I had in stock and still nothing.
 
occurs to me to ask if those bursts happen while going up an incline - fairly normal for a new motor and it may be a bit lean, but not really easy to adjust that till motor runs in more
 
Okay I'm just going to run a checklist of what I've done.

  • Made sure fuel mixture was right, 24:1 and that petcock filter was clean
  • Fuel getting to in line filter
  • Fuel getting to carb
  • Made sure the bowl was filling up and float was allowing sufficient amount of fuel
  • Took carb apart and hit everything with carb cleaner and then hit it with air
  • Removed and replaced head and head gasket multiple times. I do not have a torque wrench so tightened everything down as much as possible without stripping or breaking.
  • Gapped spark plug to .025
  • Tried multiple spark plugs
  • Made sure spark was clear and strong
  • Removed kill switch
  • Checked magneto timing by making sure the key way was in the 1 o'clock position
  • Took performance exhaust off and tried stock
  • Replaced intake and exhaust gaskets
After going through all of this, the problem still persists. I put a compression tester in and it read out at 160, which seems really high to me. Also found plenty of oil in my exhaust from running 16:1. Another note, the spark plug is pretty dark and is wet when I pull it out after attempting to start. And the top of the piston is pretty dark as well.

That's it for today, I need a beer.
 
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sorry I mistyped above. I meant a bit rich rather than lean

that high compression reading could be oil residue build up in motor, or just a bunch of fuel in bottom end from not turning petcock off

I like 32:1 after some break-in, but you didn't say if problem is mostly while going up hill, or if motor has significant miles on it now.
 
crassius said:
sorry I mistyped above. I meant a bit rich rather than lean

that high compression reading could be oil residue build up in motor, or just a bunch of fuel in bottom end from not turning petcock off

I like 32:1 after some break-in, but you didn't say if problem is mostly while going up hill, or if motor has significant miles on it now.
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No now I can't even get it started. When it was running I was getting the jumps on everything, flat, incline and decline. It made the 5 miles trip then wouldn't start again. Cleaned spark plug and was able to do a lap around the block before she died. Haven't been able to get it started since. That's what the checklist is about.
 
for a no start with compression that high, I always start by trying to blow out any excess fuel in bottom of motor - 4 out of 5 times, that's it
 
if one doesn't have a run-bench available, just take out spark plug and UNPLUG CDI blue wire to prevent fumes from starting a fire and be sure petcock is off, then pedal it a lot to blow fuel out plug hole - after a bit, reconnect plug and CDI and try starting it (this may take a lot of pedaling)
 
Question; I got a copper head gasket kit with two gaskets. One is .41mm and the other is .61mm. What happens when I change the stock .70mm with one of these? Haven't been able to work on the bike this week, had all four wisdom teeth pulled, but I plan on getting to it asap and posting results.
 
I might look into the cdi. you can unscrew the wire from the cdi and tighten it back down. they do come faulty out of the box sometimes. just to leave no stone unturned.
did you mention you had the intake and that gasket off? an air leak there is not good
 
chmn22s said:
I might look into the cdi. you can unscrew the wire from the cdi and tighten it back down. they do come faulty out of the box sometimes. just to leave no stone unturned.
did you mention you had the intake and that gasket off? an air leak there is not good
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CDI is fine as I am getting a strong blue spark. As for the intake and that gasket, I have replaced the gasket several times.
 
Don't over think your bike, if it runs good enough to ride the best thing to do is just that, ride it. The very first I built gave me some of the same problems or I should say it didn't meet my expectations of what it should do. After about 200 hundred miles it got much better, keep a check on everything and keep the usual parts greased like the right side gears and the bucking bar on the left and enjoy it.
 
Greg58 said:
Don't over think your bike, if it runs good enough to ride the best thing to do is just that, ride it. The very first I built gave me some of the same problems or I should say it didn't meet my expectations of what it should do. After about 200 hundred miles it got much better, keep a check on everything and keep the usual parts greased like the right side gears and the bucking bar on the left and enjoy it.
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I'm just trying to get the bike running again. That's what the checklist is about. But thank you for the insight
 
2 strokes foul spark plugs easy, especially if you're running 16/1. I run 24/1 from the start with good oil designed for air cooled pre-mixed use. I would install a new plug if it were mine, don't lug it either, pedal if you have to so the engine doesn't have to lug on hills.
 
I pedaled for a good hour without the spark plug in to get the fuel out, and tried a brand new ngk bp6hs, and it still isn't firing up. I did get one short burst where the bike almost flew out from under me but that lasted less than a second.
 
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