Help me pick a trany for my 142F

michael whiteman

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Mar 2, 2021
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141
Jerry..........I was under the impression the 142F (49cc) and the 144F (53cc) engines were the exact same thing with only the piston diameter being larger. Anyone, correct me if I'm wrong. It surprises me to hear your rocker arms look different. This makes me think you probably have a 53cc engine. The only way you can tell for sure is to split the case open and slowly lift the cylinder upward until the bottom of the piston skirt is exposed. Stop right there!....if you lift it further the rings will pop out and you'll have to compress them in order to get it all back together. Take a micrometer or dial caliper and measure the piston diameter. This will confirm the size of your engine. 49cc = 41.8mm or 1.646in 53cc = 43.5mm or 1.73in
 
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michael whiteman

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Mar 2, 2021
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141
Mike St.........I'm going to order this kit like yours and Jerry's. I think it's a great deal for $180. Hopefully my pulley won't arrive bent. After looking at the assembly drawing, I think it would be rather easy to straighten it out after taking it out. Definitely worth the trouble to ensure a longer life span. I think I'll do the Oil-Lite bushing upgrade to mine immediately and drive it till it drops. Then replace the whole trans with a GruBee 4G1B.

What was your issue with the 415 chain?? I wasn't planning on having to replace that too.
 

michael whiteman

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Mar 2, 2021
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Mike & Jerry: I just spent a few too many hours tonight reading some of your posts from years ago. I also read that some of the new 53cc engines have a STEPPED SHAFT unlike the tapered or straight shafts we have dealt with in the past. Good luck finding a better clutch for that if the original one is a POS. What shaft is in you guy's engine?? I thought, worst case scenario, buy a $40 tapered crank and swap 'em out. Reading on there are conflicting views on whether the side cover also needs to be replaced. Seems everyone has their opinion and that's OK, but you two are actually doing it. I think I'll hold off on my decision till I hear from you. Ultimately, I want to install a GruBee 4G and I want to make damn sure it will fit with a clutch that I can upgrade also. As a newbe, It's really hard to make some of these decisions without actually seeing the part in my hand. Most of the China E-bay people can barely communicate and have little knowledge of what they are selling. Frustrating for sure. Sincerely, thanks for all your input on this.

Oh yeah, I was surprised to see some of these newer 53cc engines have a diaphragm carb. I don't think yours does though??
 

JerryAssburger

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Apr 20, 2017
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Just a float carb on mine. I also have not pulled the clutch rotor assembly off to see what sort of shaft lives under there. As far as the side cover, are you talking about over the pulley and drive belt? I see no issues with that...?

I apologize for not having more in-depth answers, but unless something is broke, I tend to not mess with things too much. (It usually doesn't end well.) My kit is running pretty well, hampered only by the carb being a typical utility engine carb, and the need for a better than stock exhaust, but those little bits are NOT deal-breakers. Hope this helps.
 

Sidewinder Jerry

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Mar 14, 2011
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2,508
Q-Matic transmissions are the absolute best overall design I have found. At this time they do not have the adapter for my tapered shaft engine and the $300+ price tag puts it out of the race for me. GruBee seems to have the next best design and great customer service from what I can tell. All of the internal components on their transmissions can be ordered separately, which is a huge plus.

I considered the 5G dual chain drive from BikeBerry. BGF sells the same exact item for less on E-bay. After waiting for ever, I was able to talk to someone in customer service. Nice enough fellow, but every question I asked him he had to run and ask his boss. The sad news is you can not buy any of the internal pieces other than the clutch bell. If that shaft breaks, which we all have seen pictures of that happening, you toss your 5G in the garbage and buy a new one. This fact along with all the terrible reviews about this company has me walking away.

Has anyone had any experience with BikeBerry's belt drive trans?? My feeling is the stress on the small pulley's shaft would be much less than the chain drive version. I'm sure none of those internal pieces are sold separately either.

What would you suggest for me? I really want to get it right the first time. This is my first build. Thanks in advance for your help.
Gru-Bee and Q-matic is the best belt drives. If it's supper strong pulling power you're after then get a Staton Inc gearbox.

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Mike St

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Jun 16, 2008
Messages
504
You can't use a Grubee belt drive on the ebay 4 stroke 15mm shaft
engine. If you have the money, go for Grubee all the way. The ebay
motor comes with a greased bronze bushing ( which I converted
to an Oilite bushing) and a crummy 415 out-of-spec.
chain that I had to throw away. The Grubee drive has two sealed
bearings which can't be beat. I would advise against the
q-matic even though I own one because it takes a straight
shaft motor that comes without a clutch. You'll be forever
married to the q-matic drive. And if you have any problems
with the exhaust that comes with the kit, purchase an
$8 4 stroke exhaust from bikeberry or bicycle-engines.com.
It fits the motor but does not come with bolts. I had to
order a box of 25 socket heads from McMaster-Carr, so I have 23
remaining. Send me your address privately and I
will mail you 2 bolts. Use a washer and a lock washer
and problem solved.
 
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michael whiteman

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Mar 2, 2021
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141
Thanks for your quick response. I agree Jerry, if it's not broke ....don't fix it! and
Mike this is exactly the information I was looking for. I was under the impression that your style trany was only for a tapered shaft engine. I guess you can not tell by a picture. It would sure be nice if the sellers would include an engineering drawing. For the price of this kit I knew something wouldn't work for me. I need a short tapered shaft engine and the 49cc would be OK. Thanks for saving my ass and for offering me those bolts.
 

michael whiteman

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Mar 2, 2021
Messages
141
Hey Mike.........I just found this video. Does this look like the inside of your trany?? Please let me know.


After this close up look, I'm realizing this might not be a bad design. Keeping this in mind...........the bushing is supported entirely by the shaft which in turn is supported by 2 large ball bearings. The shaft is NOT going anywhere. Until the belt starts spinning, there is no pulling force on the bushing, the shaft is just freewheeling inside of it. When the clutch is fully engaged the bushing and shaft turn at the same speed. So, the only time the bushing is under load is the time it takes for the clutch to lock up. Not long at all.

I have only one suggestion. Take that metal retaining washer and drill a 1/8" hole through it that will line up with the opening between the shaft and the bushing. By doing this it will be real easy to apply a couple drops of oil so it will wick up into the bushing.
 

Mike St

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Jun 16, 2008
Messages
504
This drive is very similar. It uses a bushing, not bearings
like the Grubee drive. He never says anything about lubricating
the bushing. I'm not attracted to building a hole in the
retaining washer for oil. It takes much more to impregnate
the Oilite bushing with oil. Maybe you can experiment
with the idea.
 

Wrench

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Nov 14, 2018
Messages
4,121
Hey Mike.........I just found this video. Does this look like the inside of your trany?? Please let me know.


After this close up look, I'm realizing this might not be a bad design. Keeping this in mind...........the bushing is supported entirely by the shaft which in turn is supported by 2 large ball bearings. The shaft is NOT going anywhere. Until the belt starts spinning, there is no pulling force on the bushing, the shaft is just freewheeling inside of it. When the clutch is fully engaged the bushing and shaft turn at the same speed. So, the only time the bushing is under load is the time it takes for the clutch to lock up. Not long at all.

I have only one suggestion. Take that metal retaining washer and drill a 1/8" hole through it that will line up with the opening between the shaft and the bushing. By doing this it will be real easy to apply a couple drops of oil so it will wick up into the bushing.
I do not have a clutch or engine like this. I have not modified this clutch, but...
Some people have modified the clutch bell by machining and installing sealed bearings instead of using that Bronze Bushing.

I hear from others that Stock Bronze Bushing is not a real Oilite Bushing. If ya use a real Oilite bushing you shouldn't have any issues All's ya would have to do every few years is to re impregnate the Oilite Bushing with oil by boiling it in 30w oil for 10 mins
 
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