Lost power, low idle

[Vikingimike01]

Hey forum!

I have a problem with my bike. I was using the first 3 tanks 16:1, and the engine ran really really good. I had the muffler off. I have finished the break-in period. I am now using 32:1 gas, 95 octane (The other is 100 wich I think is too strong).

I have just now started to feel the bike not having power a couple of weeks ago. One morning I started it up, and it wasn't accelerating, it's idling very slow, sometimes even stopping (The idle screw is in so much, that if i twist it 1/4, I can't twist the throttle) the spark plug is light grey, i have fully cleared it with baking soda, and with a pin, put it back, still. I have tried every possible C-Clip position (Stock NT carburetor) If I don't have the throttle at least 1/2 pulled the engine doesn't ignite (From what I can hear) and only goes if I have it pulled fully. I have sealed both sides on the intake manifold with red hi-temp silicone (It doesn't melt untill 340 something celsius, or 644 fahrentheit) and it still does that. Not sure if it's an air leak still. I do have the low idling, wich when I'm not moving and have the clutch pulled, for some reason it fluctuates in RPM's a bit. I also hear a ratling or clanking sound inside the engine. I have looked into it and saw like a white paint like thing on the walls, they looked like they were dripping, but were completely dry.

Could it be that my piston rings broke? Or does it not have compression? The head bolts are tight, the manifold has 1 screw that broke, also the part of the engine broke that the screw should be going into. I have replaced them with hex screws but still the same problem.

EDIT: I took off the upper engine part. The head part only had 2 flat washers on the bolts under the nuts. Also, inside the combustion chamber the whole thing was black from oil and carbon (Remember I only used around 4 tanks, so why the carbon?)

The other thing, the upper body where the piston moves up and down, the walls were missing most of the chrome, it looks like it came off. The piston top is black from carbon, and under the 2 piston rings there were burn marks wich were amber.

 

[crassius]

why was muffler off? did you run it that way?

check compression with a gauge - sometimes breaking the mount on side of barrel will warp barrel

 

[Vikingimike01]

I was running with my muffler off, yes. It's because it kept filling with oil in the break in period, and then i either had get off, unscrew it, drain it, or the engine would stop-start-stop-start-stop-start because of the oil blocking it.

I don't have a gauge- I can't get one. I have a mechanic living 2 houses away, I'm going to ask him today if he can help. I've also heard that you can just put your thumb at the spark plug hole, and move the bike. I don't know how true that is.

About the barrel, wich barrel? Only the screw broke and the place where the screw goes in, at the port. The intake manifold didn't break and didn't bend.

 

[crassius]

I have seen folks break out the studs for exhaust or intake, and the soft aluminum of the barrel (cylinder) warps a bit making piston too tight to move well. That doesn't always happen though, and easy to check that piston moves freely up and down.

Never seen a muffler get full and need to be drained except if motor is filling with fuel due to bad float or petcock left on while bike is parked - either way, that is not a reason to run the motor without a muffler. Cold air sucked back into a hot cylinder can cause damage to piston or in rare cases, cylinder walls.

Most auto parts stores will loan a compression gauge for free.

 

[Vikingimike01]

So. My piston walls had the chrome come off. Is it because of the cold air being sucked in? I've had the engine running very hot in colder temperatures and it was running fine. If the chrome plating came off because of that, I'm going to be mad.

I'm getting a new piston and a new upper engine. Is it worth buying windowed pistons?

 

[crassius]

cold air could easily do that, if you want to run with no muffler, just saw it off leaving about 6 to 8 inches of straight pipe that will get hot and warm any air that gets sucked back in

a windowed piston is usually only used on reed valve motors

 

[Vikingimike01]

Thanks!