Lack of power/bursts of power

[D.Knight]

Different box movers. Maybe the ones at the kings shipping facility actually know what the parts are.

Makes sense. I live not far from the gasbike warehouse and it still takes a month to get a package from them.

I didn't have it long enough to do any accurate tests of RPM's, speed, etc. All I can say is that bike hauled ass.

That's too bad, I believe you.

You weren't kidding about that velocity stack. I put it on and immediately I had trouble getting the bike started. When I finally did get it running, I was just bogging out with a complete loss of power. Idle was fine and rev'd good with the clutch engaged, but as soon as the clutch was disengaged, there was nothing. I had to use the choke on and off just to get back around the block with some a-hole honking at me from behind the whole time. Not recommending that POS for anything.

 

[KCvale]

You weren't kidding about that velocity stack.

Velocity stacks, boost bottles, lots of stuff out there is just add-on junk that does nothing and they mark it up like 300%, hence the intense marking and hype on their web sites, that's what makes them the big bucks.

Just don't fall for the hype.

 

[D.Knight]

So it seems the title of this post just wants to haunt me.

Was riding back from work and about half way in I heard a pop come the motor and lost about half power on flat, 3/4 up hill. Got home and took spark boot off and it was smoking.

Replaced boot, and took 3 prong plug out and put a bp6hs. No difference, though throttle with clutch engaged responded fine. On another test ride with a different plug, there was another pop with just a moment of complete loss before it went back to slugging.

I didn't notice anything wrong with the head gasket, but I replaced it with a new one. I took apart the carb and cleaned it. Upon doing so I noticed the gasket was broken so I made a new one. Still nothing.

When I was testing the idle, trying to keep it alive, there was a third pop and I lost everything. No start, no nothing. Replaced the cdi, no start. Went to look at the magneto and I noticed there was oil all over my hands when I was holding the plate. Turns out the seal must have popped because there was oil everywhere in the magneto housing. Took everything out and tapped the black seal into its home. Put everything back and replaced magneto. Taking it out of the garage for a test run, I noticed I could roll the bike with the clutch disengaged so I put the compression tester on and it read 60.

I'm not seeing any other gaskets that look like they might have blown, theres no oil or fuel coming from anywhere. I'm afraid that 3 prong plug might have been too hot for the motor and screwed something.

 

[crassius]

you may have lost the thin spring that keeps the seal tight on the crank - it is on the inside of the seal, while checking that, check the crank to be sure you can't lift the end of it with a screwdriver prying against the case

unless that seal looks perfect, I'd get a new one anyway

 

[Greg58]

If you lost compression you may have a broke ring, or the plating is coming off of the cylinder.

 

[D.Knight]

Which is the seal that I need? I see seals on the websites but none say which it is. Just 1 or 2, large or small

 

[KCvale]

If you lost compression you may have a broke ring, or the plating is coming off of the cylinder.

I agree, pull the cylinder and take a look.

 

[D.Knight]

I agree, pull the cylinder and take a look.

Well, good thing I have spare rings and a spare jug. I'll check that out

 

[D.Knight]

Looks like it's a good thing I have a spare top end, haha.........

 

[Greg58]

From the looks of the piston the clip came out and started the damage, be sure to clean all the pieces out of the crankcase or you'll damage more parts.

 

[crassius]

on plus side, your seal may be good (BTW mag side is the thin one)

 

[D.Knight]

on plus side, your seal may be good (BTW mag side is the thin one)

Awesome thanks crassius

 

[D.Knight]

From the looks of the piston the clip came out and started the damage, be sure to clean all the pieces out of the crankcase or you'll damage more parts.

Where the gouging began isn't where the 2 ends of the seal meet, so I don't think it was the seal that initiated the damage. Not that it matters too much, but I think the 3 prong plug heated the jug up to the point that it made the aluminum brittle and caused a blowout in that area that has minimal material due to the amount of pressure applied from compression and combustion. I'm just thinking out loud though, I'm no expert.

 

[crassius]

that gouge looks like a wrist pin clip with two grab bars came out

this kind

rather than this kind

 

[D.Knight]

that gouge looks like a wrist pin clip with two grab bars came out

this kind

rather than this kind

I actually pulled one of each out of the piston when I was disassembling so it wasn't that

 

[Greg58]

I doubt the plug had anything to do with it, if so the top of the piston would be scorched. What does the top of the piston look like?

 

[Greg58]

that gouge looks like a wrist pin clip with two grab bars came out

this kind
That's what I thought.

rather than this kind

 

[D.Knight]

I doubt the plug had anything to do with it, if so the top of the piston would be scorched. What does the top of the piston look like?

Scorched. I'll send a pic in* a few when I get home. But it's scorched with plenty of black residue

 

[D.Knight]

This is what I pulled out

 

[D.Knight]

This is what I pulled out View attachment 95468

And if you notice, since the arrow faces the exhaust port, the gouging occurs only where the cylinder blew up