Reliability of 4 cycle clutch and gearboxes

I would love to hear more from people with these gearboxes. I'm an eternal optimist- there has to be more than one person with a good experience.
 
I've got one, well not the "hoot" itself but the upgraded model with the angle cut gears. The gearbox itself runs fine, have had a problem with the sheer pin on one of the gears inside breaking, but that was what it was supposed to do when the idler pulley got too loose and dropped down causing the chain to wrap around the engine sprocket. Got another and put it all back together, everything works fine.

Well there is one slight "problem" this GB gets very warm while going down the road, you can feel it against your leg. I'm guessing I need to use heavier grease to cool things off, as the white lithium doesn't seem to be doing the job.

As far as acceleration, and speed goes, I have a 44 tooth rear sprocket and i'm actually afraid to keep it at full throttle for more than a few seconds at a time I always end up backing it down to half throttle or even less. I don't have a speedo but I know it feels fast. even faster than the electric panterra 750 watt scooter I had that was easily capable of cruising between 25 and 30. (it wasn't a toy type scooter, but a full sized Vespa type electric)
 
My Grubee Skyhawk 2 is OK after 1400 kms of mostly hard & fast use. I use lithium marine grease and lots of it but any grease will get thrown off the cogs at those revolutions. Doesn't seem to mind not being wet in oil. I think the Titan is probably much better but it's a rear mount. I have read some OK things on this site about JL Hoot gearbox and I will soon know cos I'll be testing one in July. I think the JL Hoot has a fixed drive sprocket - i.e no freewheel which makes it a real danger to ride. Freewheel rear hubs are a pain cos they need a total wheel rebuild. From what I've read and been told on this site the Staton NV (rear mount) seems the best of them all as far as pulling power goes. I see they offer a warranty for life on the NV but I've not had one so can only go on what I read. Anything 4-stroke is better than those HTs in my experience.
Hang on, Fetor 56 is right, I only saw one report on the JL Hoot but it sounded good from what I remember - wasn't noisy and pulled well. Grubee is a bit gutless on the hills. I would be surprised if the JL Hoot is good cos it looks very HT and it's made in the same factories.
I'll soon be able to give a report on it.
 
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I would love to hear more from people with these gearboxes. I'm an eternal optimist- there has to be more than one person with a good experience.

HoughMade, I'm getting a Huangsheng & JL Hoot garbox at end of June. Will have it mounted on my Merida MTB soon thereafter and will be putting it through it's paces and comparing it to my Grubee 2 rig from Bicycle-engines.com. In July I'll post a thorough report on it's performanceand on the whole kit. The build will take a long time cos there are all those chinese studs & bolts to replace and the welding on the engine tray looks like it was done by a blind baby. I can see from looking at it that there will be lots of headaches getting it assembled to a decent standard. God knows what size the shaft is on the motor but it's not the one on the other Huangsnengs or the Honda GXH.
 
It's noisy, though not uncomfortably so. about the same level as the motor itself. just makes a whine while going down the road, the most noise it makes is actually when you let up on the throttle and the clutch doesn't have time to release you get an instant sound of engine braking as it slows the bike down to a crawl. mine may be quieter than other JLs though not "quiet" by any means because I've had it apart and personally aligned all the gears, bearings etc inside so everything meshes. I do like the fact it has the beveled gears, everything fits together better.

I can't compare it to another GB because I've only owned this one. But If hindsight was 20/20 I would have spent the extra money for a Grubee kit.

John, about the fixed sprocket, yes it does have that, and letting up on the throttle at speed causes instant engine braking, slows you right down though while disconcerting at first it doesn't seem dangerous, you just have to get used to backing the throttle down gradually instead of just suddenly letting go. And once the revs drop below a certain level the clutch releases anyway and it does "freewheel" albeit with the gears inside the gearbox turning. I'm personally seriously thinking about getting a freewheel rear axle to relieve this problem.
 
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Thanks for that info Chuck, much needed. Engine breaking is great but my concern was about wheel lock-up in the event of engine seizure which is what nearly killed me once on the HT and another time when the chain tensioner spindle threads stripped and the tension wheel slipped causing the chain to loosen and get sucked into the HT drive sprocket chamber where it kinks and locks up on the first bend and throws me over the handlebars. At 56 years of age I don't take kindly to these things happening.
BTW didn't your kit come with a rear hub freewheel sprocket? If not then I reckon it will do exacltly what the HT does when it seizes. You don't get time to disengage the clutch (it happens so fast that you just get time to put your hands out to protect your face) and whether the 4-stroke would disengage on seizure I don't yet know. For the price of a freewheel sprocket it really annoys me that they can't be bothered to include one - even as an optional extra. My next purchase will be a Dax or a Staton because they are designed by people with skills who care about the product they are selling.
 
Thanks for that info Chuck, much needed. Engine breaking is great but my concern was about wheel lock-up in the event of engine seizure which is what nearly killed me once on the HT and another time when the chain tensioner spindle threads stripped and the tension wheel slipped causing the chain to loosen and get sucked into the HT drive sprocket chamber where it kinks and locks up on the first bend and throws me over the handlebars. At 56 years of age I don't take kindly to these things happening.
BTW didn't your kit come with a rear hub freewheel sprocket? If not then I reckon it will do exacltly what the HT does when it seizes. You don't get time to disengage the clutch (it happens so fast that you just get time to put your hands out to protect your face) and whether the 4-stroke would disengage on seizure I don't yet know. For the price of a freewheel sprocket it really annoys me that they can't be bothered to include one - even as an optional extra. My next purchase will be a Dax or a Staton because they are designed by people with skills who care about the product they are selling.

I can't be sure but engine seizure might not be a factor as it's completely possible to kill the motor while cruising and still have enough free play in the centrifugal clutch to allow it to coast and or be pedaled. the only thing that might prevent this is if somehow the clutch got stuck engaged and/or the gears inside the box got jammed. Even then it would probably just do what mine did when the chain jammed, snap a sheer pin, allowing the rest of the gearbox to act as a freewheel.

I've actually had the engine die on me while riding with no problems, that's what I get for only putting a few ounces of gas in for the first test run. LOL


Correct me if i'm wrong but doesn't the HT use a mechanical, manually engaged clutch? if so then there's no release mechanism, which is probably what caused your problem, with centrifugal clutches they release when rpms drop below a certain level. I would think the motor stopping (0 rpm) would definitely be below this level.
 
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