Cryotempering Happy Time 2 stroke engine

[chrisnbush]

approx. 2500 miles on my shallow cryotempered engine. I have made break even

I haven't lost any power, though clutch might be slipping a LITTLE, either put in new clutch pads or check for grease on the clutch plate (I pumped grease into the grease fitting around 2000 miles, I pump it in until it just starts to come out the chain sprocket side bearings. It comes out the clutch side too and provides grease to lubricate the gears so I NEVER have to. Haven't had a problem doing this, if you think about it, the centrifugal force of the clutch plate should prevent any grease from getting in there - unless you overfill it).

So I have almost exactly 1 whole year on the motor, and 2500 files. Going for 3000 (but may need to install clutch pads)...

Better than my DAX rear mount. Love the company, but I can't seem to get a pair of jackshaft bearings to last me more than 1000 miles - this was max, my last set only lasted 200 miles ! I am trying to "get" to a center mount 4 stroke situation (DAX has a clutch with integral freewheel - this is the WAY TO GO) along with a rear mount GEBE. I want the centermount for the snow, as I like cruiser style, studded tires, and coaster brakes for winter driving - 4 cycle for gas MPG and engine reliability. But still want the rear mount still as I have dual suspension on the DAX (nice !) - the only other setup that can deal with suspension stress on mount is GEBE I believe.

Not sure why I remain addicted to these things, I tell myself it is the MPG, but not sure I am breaking even with the parts, failed setups (had a friction drive that just doesn't work up here, and the DAX has been problematic for ME), etc. I think really it is the ability to develop them and move toward my goal which is real, reliable, non-auto (!), transportation along with the lifestyle.

Happy riding !

 

[GearNut]

Thank you very much for the up-date!

That is alot of files on your engine.

The addiction is not a bad thing, at least it helps keep you out of trouble.
I really like the GEBE set up as well. I read somewhere that they can slip when wet. Considering that they run a toothed belt and pulleys, I cannot for the life of me figure out how.

Have you thought of the scooterguy frame mount?

 

[chrisnbush]

When you say the frame mount, do you mean the front mount - the one the requires the shift kit ? If scooter guy has a rear mount kit I would definitely be interested, if it was heavy duty like his stuff seems to be - so I could put it on my dual suspension.

Does he sell a rear mount ?

Thanks

 

[GearNut]

I was referring to the front mount/ shift kit kit.
I went to his web site to see if he does a rear mount setup too.
www.thescooterguy.org
Could not find any more info, it is "disabled".

 

[chrisnbush]

Well, time for an update. I have 3103 logged miles (give or take 50 miles) on my cryotempered HT happy time 80cc motor.

To recap: motor was originally from DAX, I suspect it is probably powerking though. Last September or so, I got the new motor and put it in the "SoLow" freezer in our labs on campus which is -70 deg c (-132 F or something) the temperature of dry ice, for 48 hours.

Motor is still running smooth and strong, in all these miles I have only HAD to replace magneto - might consider not freezing that item next time. I did just replace both the drive and rear sprockets, and not too long ago I pumped more grease into the clutch. But thats it.

Seeing how I got 1500 on my first HT, then 2500 on my first DAX, neither being cryotreated I consider this one a success - quite possibly this is a coincidence - but since I have the facility available and it is easy to do, I will try my next one also. But nothing less than quality of PowerKing I think, that is if I can still get one...

I probably have lost a little compression on it, but it is smooth and runs great. It is currently reliable transportation, has been for some time. I may put in new rings at some point, don't know about a cylinder head. Thinking rings + a slant head I bought some time ago but never installed might be an improvement.

I will keep posting until it dies in any event. Right now working on my reincarnation of the moon dog, put in the Grubee (Birddog dist) center mount with my original DAX rear mount Titan (78mm clutch) - waiting on a Grubee 4g clutch along with wide pedals. Had to cut out the center stays on the moondog to get the motor to fit in, but it still looks sweet. Guy told me 4g clutch for 78mm was 5:1, with my 56 tooth rear sprocket hoping to have enough torque for the hills around here. We will see...

Regards

 

[GearNut]

Thank you very much for the up-date!

 

[chrisnbush]

My final post on this thread - motor is going

crytempered HT 80cc motor going on a year and 1/2 ago. I am at just over 3400 miles and am losing power.

So I pulled head. Rings look fine, cylinder wall looks fine - nice and smooth. And wrist pin / wrist pin bearings are also fine - slight wear lines in wrist pin, but no grooves at all. I have seen grooves in wrist pins. The only thing I am seeing is a little shellac like build up on both sides of the piston, below the rings. Wondering if a little compression is blowing by the rings. If so, since the rings are identical to mostly unused ones I have on hand (maybe 10 hours on them) in terms of thickness, wondering if maybe either the spring of the rings (tension against the cylinder wall) has lessened, or, smooth as it is, the cylinder wall has worn larger.

The only thing I can see definitely is increased play at the lower end, on the connecting rod where it connects to the crank shaft - those bearings. Lots of side to side play, but just a tiny bit up / down play.

I am thinking it is the lower bearings. Have read a lot of posts on this forum on the HT, but at this point, having logged about 10,000 total miles on these motors I would say purchase of piston + cylinder head for "rebuild" would be waste of time for well maintained engine. If I were to do anything at this point, I would buy ONLY a new crank + rod, dissassemble and rebuild the engine with all the existing parts - BUT might also put new rings in if they maybe have lost their "spring" in the heat.

By the way, the two engines that catastrophically failed on me (I have had 4 total) failed from the upper wrist pin bearings failing, and the bearing roller becoming spectacularly lodged between the piston and the cylinder wall with really awesome gouging !...

ALL of this being said, I am gettting out of the 2 stroke HT engines for the following reasons, in order of decreasing importance:

1. Its funny, but I think the mixing of 2 stroke gas with oil is the main reason, not for the effort, but for all the attendant mess, particularly increased dirt and grime on the bike, engine, chain, etc. I am using this as alternative transportation, and I have ruined too many pairs of pants and shirts stopping for a quick, usually easy, fix to one thing or another.

2. Although I think the motors are an excellent value for price / lifetime of engine, the quality of the motors / kits cause me to spend TOO much time working on the bike to keep it in top shape, for transportation purposes. I have many other projects to work on.

3. The import ban

4. Gas mileage of 80-90 mpg gallons is not that great for a simple bicycle + motor, if you remember that a prius these days might really (!) get 40mpg + considering cost of electricity, etc.

5. Dirty two stroke emissions

SO I am concentrating on my 4 stroke centermount at the time. Think I might be giving away all my two stroke used parts (I have a considerable amount of useable junk...). Although the 4 stroke doesn't have quite the power, it is cleaner (not clean !) to work with, quieter, and at least at first indication the engines have a much longer duty cycle. I've got 3K on my Hua Sheng (Titan) and it hasn't changed at all. I do think eventually I would like to get a GEBE.

This is all just me, where I am at. Enjoy your HTs, if you have the time - it is a lot of fun rebuilding, etc. I love my motor bike, and can't ever see myself getting a moped and funding some big polluting plastic fabricating chinese company (just me again). I just need something cleaner - go figure - that is the main reason.

 

[Anigai]

VERRRRRRRRRY interesting, i only hope that ill get 3400 miles out of my HT lol

ill probably end up taking it apart after 4 or 6 months down to tiny bits, buying the new parts and replacing the ones that are worn.