2stroke kits reliable enough for commuting?

G

GPXRacer

New Member
I got a Zoombike 66cc kit two months ago. My plan was to use it for commuting due to the fuel economy of my Suburban.
I put this kit to my mountainbike and had trouble all time. I never could ride it 2 days in sequence without breakdown.

I would like to know if these Chinese high quality kits ever get reliable or if it's more a toy.

I drive up to 25miles one way with the bike, the kit has run around 500miles. Till now I experienced great customer service with Zoombikes, they always helped me.

Breakdowns happened till now:

- exhaust pipe clamp broke
- replaced pipe clamp broke again after 1 ride
- pipe gasket blew off
- stock exhaust pipe felt apart - replaced with expansion chamber
- master chain link blew off- removed and closed without master chain link
- spark plug boot felt apart inside
- some problems with the rear tire and bad replacement parts caused 3 breakdowns
- choke lever vibrated lose and stopped the engine
- magneto/ generator failed
- expansion chamber broke at the connection to the engine
- bad problems with slipping clutch - fixed
- carb siffing

- still haven't fixed the jetting as it stops pulling above 30mph.

For sure I forgot some breakdowns. As it's murphys law the breakdowns always happened far away from home...

I have a old high end mountainbike with front suspension. I use it in Los Angeles.

I would like to know if there is any chance to get this thing reliable. I'm already thinking about to remove the kit from my bike and to put it on eBay.

Marc:-||

Do I really have bad luck
 
they can be sumwut reliable once as i call it git the bugs worked out. the kit i have now the 1st month i had i lost 2 master links. wind up hooking the chain together without 1 aint had a problem since. the pipe gasket is kinda normal for these thangs. i done replaced mine. a good gasket maker works good. replaced a few parts due to my mess up lol.i had zoom kit as the first 1 of these i ever built about 2 years ago. was great lil motor. sounds like maybe u got a bad 1. like any other motor no matter who or where they are made. there will be defectived 1s
 
I have also had a bad run of luck before but I expect this to happen. The motors are cheap and yes you def. can just buy a lemon..

I have heard that the 4 strokes can be a little more maintenance free but I cant say from personal exp. The 2 strokes arent for eveybody. You need alot of patience and like to tinker on it even when its not broken.

I find that I could think that my ride is completely fine but then find maybe say a couple of spokes have loosened up. Rather than continue to tighten them up on a regular basis abit of locktite will go a long way blah blah blah..
 
Those all sound like normal problems from what ive been seeing on this forum. If you think a 2 stroke is going to be like a car/motorcycle it isnt. You need to check and then recheck everything about once a week on these things to make sure everything is tight and adjusted properly. The mags that come on these are notorious for failing. Best to keep an extra on hand at all times. The stock exhaust is garbage. Mine clogged in about 2 weeks and I had to drill it out for it to work. BTW it runs great now but the tip has fallen off before until it put an extra nut on it, hint hint wink wink. It sounds like you are using a factory plug wire and boot. Get rid of it as it is garbage. Go to any auto parts store and get a real wire and boot, they are about $5 for a cheap one and about $10 for a high performance one. While doing that get yourself a new plug, ngk b5hs, b6hs, or b7hs. The b6hs would be around the factory temp rating. 5 hotter 7 colder. At 500 miles you should really think about replacing some of the parts that take more abuse. What kind of expansion chamber were you using that it fell off, that one got me wondering. Also if you really want something really reliable shell out the bigger bucks and get a 4 stroke. Hope this helps some.
 
the fitter at work is making me up an exhaust bracket atm to take some of the weight hopefully she wont ever fall off.. not that it ever has.
 
Everything sounds like I should get rid of this kit and get a motorbike.

The expansion chamber was from the Zoombike distributor in Canada. I used a clamp to support the expansion chamber. Normally the bolts should brake off but the chamber itself broke.
I was on my way to get the sparkplug/boot/cable this morning when the expansion chamber felt of. I will safe this money now...
 
If you can, use silicone tubing and some worm drive clamps to put it back together. Or better yet find a buddy with a welder. You have to know at least one. If not take it to a muffler shop. Im sure they wont charge you very much at all, and it will probably end up better than factory.

Id keep it.
 
Hey GPX I can help you if you want...I am local and can get that exhaust issue solved. I can also upgrade that chain for ya... or ya can shell out and buy one of my FOUR reliable bikes that far exceed 30mph. Ha ha

Let me know

CCC
 
I have a Zoom 48cc. Most of my failures have been related to the exhaust. Always when running 30 or above. I don't think it would be as much a problem if I kept speed 25 or below. Vibration at high rpm is the problem. Things break when you ask them to run at 100%
 
It's been my experience that the 2-strokes are pretty reliable if you just know all the little tricks to building it right the first time. ;)
 
Thanks for your offer to help. I think I have been to the garage of VeniceMotorBike once and have seen your work. I'm pretty sure you would have saved me from some breakdowns, but I couldn't afford it.
I decided to give up. .kick2.
I will return the kit or sell it as used kit (I'm in Los Angeles). Here are some pictures from the broken expansion chamber.
 

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well i got a kit from zooms and yes it did seem i worked on it everyday but i havent really had to work on it recently i guess the bugs have been worked out there are two many things i have done to this motor to even remember but it has taking some seriouse abuse from me and kept up the best thing i ever did was make my own chain tensioner
 
GPXRacer said:
Thanks for your offer to help. I think I have been to the garage of VeniceMotorBike once and have seen your work. I'm pretty sure you would have saved me from some breakdowns, but I couldn't afford it.
I decided to give up. .kick2.
I will return the kit or sell it as used kit (I'm in Los Angeles). Here are some pictures from the broken expansion chamber.
Click to expand...


Don't give up yet!!! The first problem that I can see in your pic is the rubber between the engine & frame... That can cause the engine to vibrate more & cause things to break.
If you can bring the bike to me, I'll hook it up for you. (for a case of beer.) ;)
 
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Listen to venice, and don't give up... its clear that the problems you are having are all related to excessive vibration... due to the mounting system you used , fix that and your zoom engine will be fine and highly reliable... i have about 2000 miles on mine now and no problems, solid mounted the engine and made sure everything was properly aligned.... David
 
Yes don't give up go see Venice and pick his brain he is a wealth of info and the ol trial and error hands on experience. I think it would defo be worth your effort!
 
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I followed your recommendations and saw Norman/Venice Motor Bikes a few weeks ago. Did the modifications with him and now the bike is pretty reliable. Didn't had a single breakdown since I met him. It even runs faster now.
Thanks again!!! xct2
 
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