New Flying Horse 80 kit
- Thread starter biknut
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george_n_texas
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biknut
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So lets see, what all did I find wrong, and what was good?
The weak side crank seal was flubbed
The pinion gear wasn't installed all the way on
The head bolts weren't very tight
There's a 1/8" dia chip in the chrome liner, at the base of the liner.
3 of the cylinder studs weren't as tight as they should have been.
The was a big gouge in the paint on the gas tank
The intake manifold was partially blocked by casting slag.
That's all I can think of for the bad. Nothing unusual there unfortunately. You're lucky if that's all you got. At least most of it is easy to correct.
What was good?
The Flying Horse piston is 6g lighter than one in a PK80 style motor.
Has Japanese bearings
The cylinder casting is decent on the outside. Way better than SkyHawk.
All the other castings look good, except for the inside of the alloy intake manifold.
I think that's everything.
So in the end Flying Horse doesn't seem any better assembled than any of the other brands. A lot of the parts are unique to Flying Horse, so getting the right cylinder or piston could be a problem later.
All I can say is, I'm glad I took the cylinder off, and I'm glad I checked the seals. It's obvious that always needs to be done at the very least. Not just this motor kit, all of the them.
I feel like this will be a good motor now.
The weak side crank seal was flubbed
The pinion gear wasn't installed all the way on
The head bolts weren't very tight
There's a 1/8" dia chip in the chrome liner, at the base of the liner.
3 of the cylinder studs weren't as tight as they should have been.
The was a big gouge in the paint on the gas tank
The intake manifold was partially blocked by casting slag.
That's all I can think of for the bad. Nothing unusual there unfortunately. You're lucky if that's all you got. At least most of it is easy to correct.
What was good?
The Flying Horse piston is 6g lighter than one in a PK80 style motor.
Has Japanese bearings
The cylinder casting is decent on the outside. Way better than SkyHawk.
All the other castings look good, except for the inside of the alloy intake manifold.
I think that's everything.
So in the end Flying Horse doesn't seem any better assembled than any of the other brands. A lot of the parts are unique to Flying Horse, so getting the right cylinder or piston could be a problem later.
All I can say is, I'm glad I took the cylinder off, and I'm glad I checked the seals. It's obvious that always needs to be done at the very least. Not just this motor kit, all of the them.
I feel like this will be a good motor now.
biknut
Well-Known Member
The problem you encountered isn't limited to Flying Horse. Any motor kit has about the same odds of that happening. That's why it's important to at least partially disassemble the motor, just to see what you can find, and fix.
I haven't been impressed with the last 4 BGF motors I bought. They all had crappy crankshafts, and one had bad transmission shaft bearings. This one seems better than all of those.
biknut
Well-Known Member
If you get a Flying Horse I wouldn't bother replacing the bearings unless you detect a problem since they're already japanese. I'm pretty sure if a crank bearing goes bad, it was damaged during the assembly. You shouldbe able to feel something wrong with it.
We're going to find out real soon how mine works. I'm installing it in the Atomic BB as we speak. It's a lot easier to swap a motor than to install it in the first place.
I agree the swap will be quick.
Where did you get the seal that you replaced ? I think I should order it and have it on hand . Also do the lower jug gaskets come off ok if they havent been heat cycled ?
What stuff should I order for the tear down ? I need to buy gear puller since I borrowed my father in laws to tear the old one down
biknut
Well-Known Member
Make sure you have a gear puller.
I lost one of the wrist pin clips trying to install it. It flew off where, I know not. Not down the crankcase though, I had a rag in it.
The cylinder came off pretty easy. The base gasket looked fine, so I reused it. The reason I reused it is because it looked ok, and it also looked like a good one. It wasn't like any of my spares.
I would want a spare base gasket anyway.
The magenito side seal is 14.8 x 27 x 3.8, an the power side is 14.8 x 27 x 7.5
These are fairly common sizes. BGF are the same. I think SkyHawk too.
The power side seal you buy probably won't look the same as the stock one, but I pretty sure it's the same size.
A spare intake gasket, but I make my own.
I think that's it.
biknut
Well-Known Member
Well, thank you my friend for warning me about the clutch gear. I kept it in my mind. Tonight I was installing this motor in the Atomic BB, and decided to take the pressure plate off and look at the clutch gear. It wobbles all around when you turn the rear wheel. I know it was exactly like yours. I know what causes it, because I've noticed it's hard to get the clutch gear on without binding the key, between the clutch gear and the keyway.
Hopefully I've avoided the problem you pointed out.
biknut
Well-Known Member
I've come to the conclusion that Flying Horse motors are good motors, but they aren't assembled any better than any of the other brands.
I still like them better than BGF. I think it's possible Flying Horse holds it's suppliers to a higher standard, but their assembly line workers are just as sloppy as any of the other brands.
biknut
Well-Known Member
I've already installed this motor in the Atomic BB. It's 95% complete. Tonight I was messing with the clutch gear. When I pulled it off I found that the key was binding in the keyway against the shaft and the gear. The factory tried to force it on anyway, and distorted to key to junk. Luckly I had a spare. I kept installing the clutch gear, but it was crooked after about 4 tries. I had to put on my glasses. I found that there was a ridge of metal in the inside diameter of the clutch gear. When the factory put the gorilla to the nut to try to overcome the binding key, it crushed the edge of the clutch gear enough that it wouldn't seat all the way onto the clutch shaft. I used a round file to get rid of the edge. Now it looks as good as any of the others I've seen.
The only thing left to do is install the exhaust, and get some gas with a break in mix. Then we're going to find out about this Flying Horse motor.
The only thing left to do is install the exhaust, and get some gas with a break in mix. Then we're going to find out about this Flying Horse motor.
I pulled mine down today, found the seal behinde the mag was cocked when installed and sticking out . Found alot of grit inside the bore and ports,pinion gear not installed all the way on crank
I drove the seal in, cleaned the casting flash in the ports and chamber. Installed the gear, cleaned the jug , put it on the bike and rode around for a bit. I barley got to ride it, my wife took it out for 5 min and then we left fore the circus .
I drove the seal in, cleaned the casting flash in the ports and chamber. Installed the gear, cleaned the jug , put it on the bike and rode around for a bit. I barley got to ride it, my wife took it out for 5 min and then we left fore the circus .
biknut
Well-Known Member
Hopefully it will be a lot more dependable this time. The stuff you did isn't hard to do, but if you didn't do it, it could easily ruin your motor.
biknut
Well-Known Member
When you took the cylinder off, did it come off easy without hurting the base gasket?
biknut
Well-Known Member
I just got it all together, and went on the first test ride. All of a sudden I forgot how to start my bike. I turned on the wrong petcock. I put the vent cap on the wrong bottle. I forgot to turn on the petcock. So after a little monkeying around it started started right up.
I'm still running the Speed Carb. Now with a 68 jet. Running an estimated 20:1 ratio. It's oiling up a stock chinese LD Z4C spark plug. I know too much oil, that's life. It's probably too rich too, because it starts up fast with no choke. Idles good. Real good.
This motor is the quietest mechanically, of all my china girls so far. Not the exhaust, It's the same one I just transfered from the original motor, that has my custom limp dick muffler, on a stock header. It's also real quiet too, but I'm mainly talking about the gear whine. I'm taking most of te credit for than after spending so much time last night getting the clutch gear to fit right. I also had to install the pinion gear correctly for the factory.
Right now it feels stronger than the 48cc, but not as strong as a X80A, or the souped up T80 I had on the Cadillac, but give it a chance.
I'm still running the Speed Carb. Now with a 68 jet. Running an estimated 20:1 ratio. It's oiling up a stock chinese LD Z4C spark plug. I know too much oil, that's life. It's probably too rich too, because it starts up fast with no choke. Idles good. Real good.
This motor is the quietest mechanically, of all my china girls so far. Not the exhaust, It's the same one I just transfered from the original motor, that has my custom limp dick muffler, on a stock header. It's also real quiet too, but I'm mainly talking about the gear whine. I'm taking most of te credit for than after spending so much time last night getting the clutch gear to fit right. I also had to install the pinion gear correctly for the factory.
Right now it feels stronger than the 48cc, but not as strong as a X80A, or the souped up T80 I had on the Cadillac, but give it a chance.
yeah the base gasket was still intact. I reused all the gaskets, none where torn and had not been heat cycled.
BTW I belive the first engine I had came with 2 base gaskets on it. I also found thru the same seller on ebay that they have complete gasket sets for $12
biknut
Well-Known Member
This time I torqued the head bolts 125 in lb. Not the 145 I did on the last two engines. I think we're a lot safer keeping the torque as low as possible to help prevent warpping the cylinder.
After two more test rides I retorqued the head back to 125 in lb. It took about another 1/3 turn on the bolts. I also tightened the intake, and the exhaust bolts. You got to check those often in the first 100 miles. Not so much after that.
Next I'm going to check the compression
After two more test rides I retorqued the head back to 125 in lb. It took about another 1/3 turn on the bolts. I also tightened the intake, and the exhaust bolts. You got to check those often in the first 100 miles. Not so much after that.
Next I'm going to check the compression
biknut
Well-Known Member
I'm pretty sure the gaskets won't be the same as the factory gaskets. Buyer beware.