Has anyone mounted a 4 stroke in a MTB frame

gary55

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I have someone wanting a 4 stroke in a MTB frame. I have not seen it done yet. I suspect that the straight down tubes of this style will not allow them to set low enough.
 
hopefully this helps. i assume you mean the hs-142f 4-stroke kits. i have the hs-142f on a semi-mountain bike. it has a slightly curved top. the downtube isn't straight but slightly angled towards the back wheel though. the engine sits on an imperfect tilt to the rear sprocket. i had to also remove the muffler cover (useless anyways), carb filter box (just need foam over carb intake), and remove the throttle assembly on the carb (made my own).

because the engine sits on an imperfect tilt, the chain needs to be adjusted with additional chain tensioners to compensate for the tilt. the cardboard sizing cutout (no plastics removed) from bikeberry is very accurate to check before buying the bike. having an imperfect tilt is not the end of the world but i would definitely not recommend it for a customer or anyone who just wants little hassle.

but, there are some larger mountain bikes out there that i think should fit with little plastic removal and no engine tilt. but, i mean you have to be taller than average for those bikes.

 

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I have someone wanting a 4 stroke in a MTB frame. I have not seen it done yet. I suspect that the straight down tubes of this style will not allow them to set low enough.
What is an 'MTB' frame?
 
hopefully this helps. i assume you mean the hs-142f 4-stroke kits. i have the hs-142f on a semi-mountain bike. it has a slightly curved top. the downtube isn't straight but slightly angled towards the back wheel though. the engine sits on an imperfect tilt to the rear sprocket. i had to also remove the muffler cover (useless anyways), carb filter box (just need foam over carb intake), and remove the throttle assembly on the carb (made my own).

because the engine sits on an imperfect tilt, the chain needs to be adjusted with additional chain tensioners to compensate for the tilt. the cardboard sizing cutout (no plastics removed) from bikeberry is very accurate to check before buying the bike. having an imperfect tilt is not the end of the world but i would definitely not recommend it for a customer or anyone who just wants little hassle.

but, there are some larger mountain bikes out there that i think should fit with little plastic removal and no engine tilt. but, i mean you have to be taller than average for those bikes.


Thanks. This is helpful. I am trying to talk this guy out of this idea. His intentions for it is a bug out vehicle, and I don't think a motorized bike provides the reliability or hauling capacity to fill this roll in off road conditions of northern Az.
 
What is an 'MTB' frame?
Hay KC. We haven't buttoned a frame down yet. He was looking at a 21" frame giant, but when I told him the frame was for someone with a 36" inseam and the frame had a bad chain stay geometry for motorized use he dropped that one. Like I said in reply #4 I don't think a MB is the right choice for his needs. I also can't find the 4G kits in stock, and don't want to use one with the bushing set up.

If he really wants one I will build him one, but I think he would be wise to get a small well engineered dirt bike.
 
The MotoPed frame was something, basically a performance soft tail dirt bike, with pedals...

2_MotoPedDoneL-1280.jpg


86cc kick-start 4-stroke and 4-speed gearbox.

I'd say look at pit bikes maybe?
 
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Great minds think alike, though the great may be a bit of a push. It is funny though because the motoped was the first thing I suggested when he told me what his needs were.
 
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