4 stroke with sickbikeparts jackshaft

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xXNightRiderXx

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Jan 12, 2017
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Been trying to find the specs for the engine I have, but there seems to be none, It's 79cc 4 stroke from the company called Gasbike, I bought it from Bikeberry.
I can provide those for ya, here's what I remember of it:
Max power: 3.5hp@3600rpm
Max torque: 3.5ft/lbs@2500rpm
Max rpm: 3600rpm
Displacement: 78.5cc
Compression ratio: 8:1

There should be an Owner's manual inside the engine packaging that contains all the specs. I have the gasbike 79cc engine, and am modifying it for the most power I can get without going crazy about it. Ive heard these things can get up to 7hp.
 

waynesdata

Active Member
Jul 10, 2017
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I am playing with the idea of a 212cc with 3d clutch and single speed freewheel.

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No after looking at Youtube much too wide.
 

MotoMagz

Well-Known Member
Aug 2, 2010
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I am playing with the idea of a 212cc with 3d clutch and single speed freewheel.

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No after looking at Youtube much too wide.
Yep very wide and the clutch set up needs some messing with.Here are 2 other options 79cc and a 212 . You can also do the 79cc set up in a 212.
 

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waynesdata

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All the more reason to have a 203 on the front at least. You want to be able to do emergency stops. Im doing a 203mm with Shimano SLX hydro on the front and a 180mm with a mechanical hydro on the rear when I build the stingray.
I do not like the feel of my rigid fork just peddling around. When I upgrade to dual crown down hill fork I will look at the issue again. No point buying caliper mount twice.

I have a rule for myself to never motorize a bike I would not want to peddle around.
 
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Onenonlynicky

New Member
Nov 8, 2016
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I can provide those for ya, here's what I remember of it:
Max power: 3.5hp@3600rpm
Max torque: 3.5ft/lbs@2500rpm
Max rpm: 3600rpm
Displacement: 78.5cc
Compression ratio: 8:1

There should be an Owner's manual inside the engine packaging that contains all the specs. I have the gasbike 79cc engine, and am modifying it for the most power I can get without going crazy about it. Ive heard these things can get up to 7hp.
The
I can provide those for ya, here's what I remember of it:
Max power: 3.5hp@3600rpm
Max torque: 3.5ft/lbs@2500rpm
Max rpm: 3600rpm
Displacement: 78.5cc
Compression ratio: 8:1

There should be an Owner's manual inside the engine packaging that contains all the specs. I have the gasbike 79cc engine, and am modifying it for the most power I can get without going crazy about it. Ive heard these things can get up to 7hp.
The exact setting spec I'm looking for is what feeler guage size is needed to set both gaps for each valve...that's what I can't find, the valve lash clearance
 

xXNightRiderXx

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Jan 12, 2017
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I called the Gasbike company, and even they didn't have the specs I needed, as the motor is built in Japan, and I asked if they could get the specs from them and they said no‍♂
Everywhere I look, valve lash is set to .004-.006 on the stock cam. "79cc valve lash" should.be the search term that brings up everything, including Necros instructable.
 
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curtisfox

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Dec 29, 2008
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If it will help, the old slandered is 8 I & 10 E. Newer Briggs specks is 7 & 9, somewhere i red these are tighter more like 5 & 7 thow. ..........Curt
 

waynesdata

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Jul 10, 2017
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Everywhere I look, valve lash is set to .004-.006 on the stock cam. "79cc valve lash" should.be the search term that brings up everything, including Necros instructable.
I wonder what happen to Necros? "4 stroke with sickbikeparts jackshaft" would make a nice instructable.

KC used to say "gears change everything"
 

xXNightRiderXx

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Jan 12, 2017
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So, considering the weight of the new sprocket, and the wrong size at that, I'm going to be going through sick bike parts for the chainring adapter, and attaching a 30t chainring. I will be drilling out the holes for larger bolts from Home Depot to handle the engine power. I will also meticulously align those sprockets for the straightest possible line. However, since I have already purchased a new chain to fit the sprocket, I will be using that until I can afford the chainring and adapter.
 
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waynesdata

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So, considering the weight of the new sprocket, and the wrong size at that, I'm going to be going through sick bike parts for the chainring adapter, and attaching a 30t chainring. I will be drilling out the holes for larger bolts from Home Depot to handle the engine power. I will also meticulously align those sprockets for the straightest possible line. However, since I have already purchased a new chain to fit the sprocket, I will be using that until I can afford the chainring and adapter.
I am also concerned about things breaking under this kind of engine power. I am looking for a way to reinforce the gear on the seat post. I may use horizontal dropout frame to prevent the rear axle from coming out under load.
 

xXNightRiderXx

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Jan 12, 2017
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I am also concerned about things breaking under this kind of engine power. I am looking for a way to reinforce the gear on the seat post. I may use horizontal dropout frame to prevent the rear axle from coming out under load.
I'm running with a qr skewer with vertical dropouts, and I haven't had an issue with the axle moving under load. Of course, that doesnt mean it can't happen, I'm just sayin it's unlikely, especially once you apply enough torque to the nuts/skewer.

Gear on the seatpost? I'm gonna need a picture for that one. If youre talkin about reinforcing the seat tube though, just drop another seatpost down in there.
 

waynesdata

Active Member
Jul 10, 2017
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I'm running with a qr skewer with vertical dropouts, and I haven't had an issue with the axle moving under load. Of course, that doesnt mean it can't happen, I'm just sayin it's unlikely, especially once you apply enough torque to the nuts/skewer.

Gear on the seatpost? I'm gonna need a picture for that one. If youre talkin about reinforcing the seat tube though, just drop another seatpost down in there.
I think the part I have circled could twist under the kind op power we will be putting out.
Brace.jpg