anything but a happytime

I was considering on my next build, mixing up some epoxy and filling the frame tubes for about 8" where the motor mounts go, to provide some vibration damping and keep the frame from cracking. That expanding foam from building places may even help, although it's really lightweight.
 
I was considering on my next build, mixing up some epoxy and filling the frame tubes for about 8" where the motor mounts go, to provide some vibration damping and keep the frame from cracking. That expanding foam from building places may even help, although it's really lightweight.

The epoxy would help, but what would probably help more is if you could get some thin steel rods to insert in the same area, then encase them in epoxy. It would be like re-bar in concrete- very strong, indeed, but tougher to execute.
 
The epoxy would help, but what would probably help more is if you could get some thin steel rods to insert in the same area, then encase them in epoxy. It would be like re-bar in concrete- very strong, indeed, but tougher to execute.

I filled mine with liquid nails it's cheap and it's easy to get it into the tubes.
BUT don't forget the bottom case has holes were the tubes are joined/welded on if you fill your tubes with epoxy it will run down into the cranks. I jammed some sheet plastic to block up these holes.
If you take your seat pole out and look down the seat tube with a flash light you will see the hole I am talking about.
AND yes all of this did make the vibs less. (Filling the seat tube and the down tube).
 
How did you get the liquid nails into the front down tube?

I drilled about a 5/16 -8mm hole about 6" from the top and just got the croking gun and squeezed it in. I also clamped the bike in a position so the down tube was straight up and down, as to make sure it did not form an air block halfway down. I also drilled about a 3/16- 5mm hole down at the bottom of the down tube, so as to let out the air and to make sure that it has made it all the way to the bottom. If you did'nt want to do that (drill holes) you could take the cranks out and in the bottom shell there should be a hole that leads into the down tube. You could hold the frame upside down and squeez it in. I had to put some sticky tape over the bottom hole for a few days, as it take for ever to dry when you have large amounts. (liquid nails)
I hope that makes sense.
When you looked down your seat tube did you see the hole in the bottom shell??? use a flash light.
 
You can bash politicians that I support, but for the love of God and country, don't bash my happy time engine.
 
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won't bash the HT kit

We built 2 of the happy time motor kits last weekend. They were ready to ride sooner then my other liquid cooled pocket bike project. For the average person yes, the HT is better at only $150 and it will move you. Myself, I had this engine and nothing to do better with it. I spent way more money, but passing traffic last night on that chopper and getting looks for the intercooler was worth the interesting result. I like the HT kit. Even if you have the time and money I wouldn't recommend this engine on a mountain bike. It has way too much torque. Looking back now, it seems I have built a small motorcycle. :eek:
 
Pablo, don't take this wrong 'cause I know you mean well and put up helpful info here, but posts like yours seal the deal for me on HT engines.
After having done so most of my life, I have now arrived at an age where I am tired of having to fix things before I use them.


There are many, many posts on this - some with detailed lists.It's worth finding those. Here's just a rambling bit of info.:eek::cool:

In general most all the mounting hardware should be thrown in the trash. Replace with good material Grade 5 equivalent is actually fine and shouldn't be brittle.

Use a good fuel filter and different HD fuel valve. The gas cap will leak, solved with a new washer and not over filling. There will be intake leaks at the carb and or manifold and or engine interface. The engine should be broken in oil rich. The plug (NGK B5HS) and plug wire should be replaced.

Plan on adjusting the carb with the needle e-clip and getting some replacement jets as the engine breaks in. Watch the spark plug for air/fuel condition.

Adjust your clutch cable sheath length (down) as necessary, lube the correct points and adjust the clutch.

Get a dual pull brake lever on the right side.

Be prepared to replace the head studs and head gasket.

Solder and shrink sleeve the wiring connections. Don't use the little (red/black) push button kill switch. (The yellow orange throttle grip push seems to work fine, IMHO)

If you decide to use the stock chain and bolt on sprocket, don't ruin your spokes, make sure the chain gets adjusted as it stretches, get a good tensioner that doesn't bail into your spokes, etc….

Get an expansion chamber and silencer. And at the very least open up the intake and exhaust port and replace the intake and manifold gaskets.

Point being there are detailed posts on all this stuff :p
 
Low cost of admission. All bike engines require some work.

The one guy riding the least because of engine problems at the PNW Rally had an rack mount, NON -HT.................
 
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