Ran well, now no power

[Greg58]

MT I use the plastic cutoff as well, on my snapper riding mower because the fuel tank is mounted higher than the carb and on my log splitter. On the log splitter I've learned to turn the fuel off and run the gas in the carb down some, if not towing it makes the float in the carb bounce and release fuel which fills the engine. After that happened I installed the valve. Greg if your cut off isn't working it could be the problem.

 

[GregValiant]

Idle musings...
I wonder how many factories actually produce these 2 stroke engines. The ones carried by every on-line store and the ones on ebay all look to be identical designs. It looks like you could take the side covers off of one and stick them on any other one. The only difference I can see are the stickers that some stores put on the clutch covers. 90% have identically finned heads and the other 10% have the same blocks but fancy looking heads. All the kits come with the same cheesy petcocks, fuel filters, chain guards, etc.. The rocker covers from a Ford would never fit on a Chevy.

I'll keep an eye on the petcock situation. It's assembled with a couple of screws so maybe I'll take a look inside and see what's up.

Also, I am running a 40t rear sprocket but I altered the 44t (that came with the engine kit) to fit the hub adapter. That might let the engine rev higher and get further into it's power band (such as it is). Any thoughts on my switching to the 44 sprocket?

 

[GregValiant]

This is ridiculous. Today I push the bike out of the garage, turn on the petcock, fuel runs everywhere. Take the carb off and this is what I see...

So I pull the float out of the original carb and swap it in. Then I go up to Home Depot. The bike ran like it did when I started this thread, but after a while it got going up to 23mph. So the high point of my day was that we were probably on the right track with the "fuel in the crankcase" theory.
But when I leave Home Depot I take one pedal stroke on the bike and the pedal chain comes off. I look at the back wheel and I'd taken off with the cable lock still on the rear. That broke (probably a good thing) but it was wrapped around the hub. After a couple of tries I get it out of there and get the chain back on. The bike ran acceptable on the way home. I can't wait till tomorrow and see what new tricks it has up it's kazoo.
I tell ya boys, I ain't feeling any love from this thing. I should have called it a GL48 because it's taking the Hardly Davison thing way to seriously.

 

[Greg58]

Greg riding one of these is like driving a old car or truck, you learn to take enough along to repair things. A couple of years ago my son in law broke jic chain and we were 30 mile or so away from the truck, I had enough in my tool bag I keep strapped to mine to get it going.

 

[GregValiant]

I've got a lot of old stuff. Motorcycles, trailer, legs, arms. But for the most part they work pretty good. I keep thinking about the "afraid to ride it 2 miles" thread. I get a smile out of that. It's like a club I belong to as well.

 

[Bikeguy Joe]

"The Greg thread". haha.
I was reading this thread then I got to the "40t" part.
Holy cats! That's some steep gears for a 50, unless you weigh 90lbs.

Now that you got it running better, try the 44t, you'll be amazed.

 

[Greg58]

Greg Joe is right, my oldest bike I built in early 2011 is a 48cc OP cruiser, I’ve tried several different gear types and the 44 tooth is what mine needs. I lost some top speed by dropping to a 41, remember 2 strokes have a power band that produces the most power and torque, the 41 tooth made my rpm fall below the power band.

 

[GregValiant]

When I got the bike and found they'd sent a 3 speed instead of a standard (and charged me for the 3 speed) I immediately learned that the sandwich sprocket mount wouldn't work on the large diameter rear hub. They sent me an adapter and I asked them for the 40t sprocket. I figured I could alter the 44 to fit and there was no reason to have two the same size. Of course the fancy adapter didn't fit either but after a couple of hours with the die grinder I got the ID to 1.87" and now it fits. The only thing around here that you could call a hill are the approaches to the drawbridges downtown. I thought that even the little motor should be OK on all the flat stuff.

So today I rode it downtown and went beach fishing (got 5 fish!!) and I got back home without anything breaking or falling off. That felt so special that I spent an hour tuning. I stepped up from the stock 70 jet to the 72, 74, 76, 78. The 78 was definitely too fat so right now it has a 77 in it. The needle ended up with the clip in the top notch. It's running pretty good. Maybe tomorrow I'll swap the sprockets and we'll see how it goes. 10% difference in the rear gear is a big difference. Acceleration right now is poor to say the least. It does get rolling though. Got it back up to 27 for a few seconds before a headwind knocked me back to 25.

And I did mention that nothing fell off right? Definitely making progress here and I appreciate all the help and moral support.

 

[GregValiant]

Time for an update.
The master links showed up and I'm running the 44 tooth sprocket. Top speed is at 23. Acceleration is poor but better than with the 40t. I'm still running the .75 jet and the needle in the top slot. It idles perfect. I did a 3d print and made a mickey mouse repair of the throttle handle. Almost lost the pedal chain guard even with loctite on the mount bolts. I added nylocks to the mounts.
I guess it is what it is. It gets me to the beach for fishing and it will be fine for tooling around campgrounds.