How Many Miles Did You Get On Happy Time before the times became unhappy ?

[HybriPed]

You are right Hybriped I have long said that these motors are a beautiful little design that would be just fantastic if they were made in Germany, UK, USA, or Sweden or anywhere with a reputation for quality. But it's the quality of them that I have a beef about. The fact that the ports are the same size on the 48cc, 55cc and 66cc and that the pistons are not a similar shape to the cylinders and all the other depressing details concerning them that show just how little care is given to these otherwise lovely little engines. As far as I have been able to ascertain the bearings are NOT Japanese. That is a marketing myth invented by some greedy capitalist. If the bearings had been Japanese then they would surely have been installed on my first Grubee 48cc that actually was of a quality that leaves anything else that has come out of China since 2005 dead. It had needle bearings but they weren't japanese I can assure you. That engine wasn't great and seized eventually but it was the best one of many many I've had since. I was robbing it today for parts and I noticed how vastly superior everything that's left of it is compared to current Grubee or Zbox kits. The throttle reel is alloy and the throttle tube is alloy - not the nylon they now use. I was genuinely shocked to see the huge quality differences in the old motor and the new ones. The whole clutch assembly is different - everything is better right down to the tank and pet cock.

You are a mine of information IJ.

I'm going to send your comments off to Don Grube and get his comments. I agree with the comment about the nylon throttle reel. That is just ridiculous. When the first one failed at about 700 kms, I realised that I just had to nurse the throttle forever. Nevertheless, I've been expecting the replacement to fail at any time for the past 2,000 kms - not what you call relaxing.

 

[Mountainman]

well that's a good THING

I'm going to send your comments off to Don Grube and get his comments.

good idea

you may also wish to let ones know who sell the un-safe chain tensioners
check their insurance coverage
someone is going to get hurt seriously -- I hate to say that -- just fact

MM

 

[Irish John]

good idea

you may also wish to let ones know who sell the un-safe chain tensioners
check their insurance coverage
someone is going to get hurt seriously -- I hate to say that -- just fact

MM

All the chain tensioners are very mild steel & cannot be tightened too hard without stripping the threads. The bolts, being stepped, cannot be replaced with good Aussie ones but if you know what you are doing they are safe as houses.
Just use 12.9 hardness steel bolts to attach the tensioner bracket to the rear chain stay and the keep the tensioner wheel on the lowest setting so it can't slip downwards. Adjust chain tightness by sliding the tensioner bracket back along the chain stay and as soon as your chain has stretched (after 175 kms or so) remove link(s) to get as small an angle as possible over the tensioner wheel. Thereafter adjust tension by moving the bracket and not the tensioner wheel. That is don't move the tensioner wheel upwards from it's lowest setting and it won't slip down. Also don't over-tighten the nut on the stepped bolt. Lastly don't expect good steel bolts from China because you won't get them. It's not any suppliers fault it's just the way all the steel bolts are made in China so replace what you can with non-chinese ones and make allowances. These kits are not for the unitiated and a bit of problem solving is needed to get them working safely plus reading up on this website.
Soon the kits will be coming from some other country because people are getting to realise that chinese factories can't cut the mustard where quality control is important. They've only themselves to blame because it wasn't for want of being told. I reckon India will step in to the rescue.

 

[loquin]

just to be clear to anyone who isnt familiar with the context of "happy time" in this thread: this thread has nothing to do with me or my business.
i got an email the other day from someone who wanted an assembled bike, but saw this thread and was skittish.
the term "happy time" was coined purely out of humor for the origin of the motors. i liked the term so much that i stole it. fair and square.

I suppose that you have to take the bad with the good ...

If you 'steal' (your words) the generic term for ALL of this class of engine, & use it for your own, there will be confusion by those who haven't taken the time to research it...

 

[alex]

I have exactly 4,667 miles on my ht 80cc kit, it's never given me ANY trouble (except with a cheap intake manifold snapping when I went through a pot hole) it always starts within 15 feet of popping the clutch.

I have a custom expansion chamber exhaust, boost bottle, and upgraded ignition wire. I run at a 32-1 mixture, and I am moderately abusive to the poor little thing.

 

[sparky]

I have a custom expansion chamber exhaust, boost bottle, and upgraded ignition wire. I run at a 32-1 mixture, and I am moderately abusive to the poor little thing.

That's the way to go. 32-1 for me, and I was hitting 34 mph today!! 33cc on a 20" bike. This engine just took longer to break-in... but it's been runnin' right the past couple days. Need to take it down to the drag strip!

 

[Porkchop]

45 kph is wide open throttle (prob with a boost bottle) and the motor is totally maxing at that speed. When the top bearing goes the piston jams in the port and the bike totally locks up. When it happened to me I was slowly going along a quiet road looking out to sea for whales and doing about 25 kph and the next second I was over the front and in the ditch. Because the rear wheel locks up the bike goes to the right. I didn't have time to get the clutch in and I use a twist clutch so my hand is always on it. 3 minutes earlier I was on the Pacific Highway - a 6 lane motorway - if it had happened there I'd have gone under a truck and been killed almost certainly.
In my opinion the kits should have to include a rear freewheel sprocket as standard so engine seizure doesn't lock the rear wheel up. I believe that without a rear freewheel you will always be risking death and at 45 kph your engine will not last. That I can promise you. If it's the bottom end that goes it's not so bad but I'm only speaking from my limited experience of massive failure - once it was top end and once it was bottom end. Top end was much more catastrophic. Both times it was with the best of my many HT motors and it was the one I kept going the longest with because I didn't know much back then. Here's a picture of the exact bike and motor that seized and nearly killed me.

Would a centrifigal clutch be an adequate safety feature ? I'm thinking if the engine came to a sudden abrupt stop, it would still lock up the rear wheel before the cent. clutch would have time to stop pulling. I have a Grubee still in the box. I don't to much care for manual clutches. I'm thinking about using centrifigal clutch along with a jack shaft ! Centrifigal clutch only for doing away with the manual ****ch lever. I agree with the freewheel feature, they should be on all of the bikes.

 

[Porkchop]

Bolt Replacement

I hope this reply is legit under this thread. If not, excuse me. I've read a lot, over and over about replacing the factory nuts and bolts with high strength ones. Should every nut and bolt , and I mean ever one of them be replaced ? I'm talking head nuts, cylinder studs, crank case, clutch cover, all of them. I have no problem with doing all of them. Cost would probably be less than $5.00 Can you take them out and replace them one at a time without doing damage to the gaskets, especially the ones that are under compression like the crank case and cylinder ? Does anyone have torque specs on them ? Thanks !

 

[Mountainman]

right -- may not be the proper thread

I hope this reply is legit under this thread

Should every nut and bolt , and I mean ever one of them be replaced ?

I'm talking head nuts, cylinder studs, crank case, clutch cover

damage to the gaskets, especially the ones that are under compression like the crank case and cylinder

right -- may not be the proper thread
and the answers to all of your questions asked
are found through out this site
but -- I believe I started this thread -- so -- no big deals today

replace every nut and bolt ?
thinking that the most important would be the cylinder studs
if taken out one at a time and replaced -- should be no problem
use site search engine for proper torque

please note -- if anyone wishes to add to these comments
please PM Porkchop -- because this post did not truly fit into this thread

ride that motor bike THING

 

[sparky]

I hope this reply is legit under this thread. If not, excuse me. I've read a lot, over and over about replacing the factory nuts and bolts with high strength ones. Should every nut and bolt , and I mean ever one of them be replaced ? I'm talking head nuts, cylinder studs, crank case, clutch cover, all of them. I have no problem with doing all of them. Cost would probably be less than $5.00 Can you take them out and replace them one at a time without doing damage to the gaskets, especially the ones that are under compression like the crank case and cylinder ? Does anyone have torque specs on them ? Thanks !

This most definitely deserves its own thread!!

Personally, I'm only concerned about mounting nuts/bolts. But if you have the time to piece everything out and get all the bolts for $5... you might as well, right? Then it'd be near-Taiwan quality instead of Chinese quality.

And definitely get the torque specs if possible, and don't over-tighten!! I'd almost rather just use the stock bolts with blue Loctite... haven't needed to tighten a single bolt since I put the Loctite on.