New engine has no power


Active Member
Local time
5:01 PM
Aug 14, 2022
142f starts idles drives. But zero power . So I have the same engine on a Seattle with a 52 sprocket it's slow (about 25-28) but it goes. Put the new engine on , finally got it lined up and tensioned and the thing barely moves I lived the gearbox thoroughly and I took the bell and lightly sanded the inside with a sponge then opened up the springs in the clutch. Sprayed them with a bit of wd40 for food measure. And the bike barely moves given I good flat road it will even finally pick up speed be but damn. Do I just need a better clutch and /or gearbox? Can someone point me in the right direction please? Money's is really tight so an economical fix would be great.
Thanks in advance.... It's a shame too I really like the look of the bike now.


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Sprayed them with a bit of wd40 for food measure. And the bike barely moves given I good flat road it will even finally pick up speed be but damn. Do I just need a better clutch and /or gearbox? Can someone point me in the right direction please?
The clutch is new Maybe the shoes gotta burn in and seat themselves. sand any glaze off the shoes and give the inside of the clutch drum a quick sanding too. Also oil that clutch bushing it might be dry and binding on the shaft

Are your RPMs high
If you sprayed the clutch shoes with WD-40 then that's your problem., clutch is slipping
Sanded drum and clutch as well as I could as I don't have a clutch puller wd only on the springs.
I'll take it off again and try a more rigourous sanding..thank you
Is the rear sprocket a 44T? I had to use a 54T for my bike to pull from a dead start. It would burn the clutch trying to start with the 44T.
Ok so on micargi I run a 52 and it pull from a dead start. On this new bike I'm running a 36 tooth cuz I wanted some speed I'm not worried about pulling from a dead stop. The thing is is when it is going the thing barely moves. Most likely the clutch and the gearbox. The company has offer to send me a new clutch but I have to pay for the gear box. Now the gear box was advertised as being a double chain which it is not so I'm kinda pissed it's eBay of course cuz I'm trying to save some cash . Should I just leave a bad feedback they are trying to meet me halfway but they advertised a double chain and sent a single. They dont want negative. So what do you think take their offer or not. Maybe wait and see how much they want?
I mean damn does anyone on here have one they could part with on the cheap even if it's belt drive or chain whatever. Advice, ideas?
I'm going to try just riding it a bit see if it seats meanwhile wrote to the eBay supplier who told me it would be 30 to 45 days for a new clutch and that is have to pay for a new gear box , even though this was advertised as double chain and it's only a single.,
Keep you all posted
You are correct in that either of these gearboxes are junk and plagued with problems.

There's much better transmissions if you're willing to pay for them. The 142f 4 stroke engine only produces around 1.6 hp at 6800 rpm. So you aren't working with a lot of power either.

If you have the Bikeberry transmission that has a reduction of 6.83\1 and are running a 10\36; the total reduction is 24.59\1. On 26" tires, your top speed would be 21.4 mph.

If it's the even crappier transmission, it only has a 3\1 reduction giving you a total reduction of 10.8\1. This reduction is nowhere near enough. You will burn your clutch up.

Depending on your body weight you need at least a reduction of 18\1 to 20\1. This would give you a speed between 26-29 mph.
If it's the BB transmission you can put a 12t-13t sprocket on it to get a little more speed.

If it's the really bad one you'll need a 60t rear wheel sprocket or use a jackshaft with a 17t and 10t on it. T-JS 10\17; JS-RW 10\36.
I'll be honest. My daily drive has a 142f it has a 525 rear sprocket and tops out about 23-25.
I figured if I bought the same engine I'd get a bit more speed out of the 36t rear. But I didn't take it to account the gearbox. I didn't realize that I made such a huge difference. Not sure what's on my micargi I bought it the customized it myself so the gearbox and the ratio is a mystery to me it runs nice it pulls from dead stop and flies up hill so I wanted to 4 stroke my other bike cuz of all the problems with the 2 strokes. I thought it would be as easy as buying a kit and slapping it on. So not the case. I'd just like the thing to be rideable. A speed in the 20s is fine. But I can't change the sprocket on the rims cu when I bought them I had a failure that nearly killed me(thanks bikeberry) so I red thread locked the bolts in. At the time I didn't thing I'd be taking my beloved yd off of it for a 4 stroke but my micargi runs so good I thought I was doing the right thing. Idk what I'm going to do now. I got Alot of personal problems weighing in on this project too and I'm basically screwed. There's literally no more money to fix or upgrade. So it is what it is I guess