cspaur13
Member
also dose any1 know where you can get replacement parts for this little engine. or can you only get them at harbor frieght. in case something ever breaks on it.
79cc 4 stroke frame mount build
- Thread starter cspaur13
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M
macarollo
Guest
You can order parts through harbor freight, just keep in mind that it takes a long time (maybe 3-6 weeks to get the parts as they come from China I believe).
This engine can be had for $80, you are almost better off just buying another engine for parts if you did have to replace something. Then next time something broke you would have the part for free.
This engine can be had for $80, you are almost better off just buying another engine for parts if you did have to replace something. Then next time something broke you would have the part for free.
cspaur13
Member
oh. i could of swore i saw a site somewhere for the replacement parts for these little greyohund engines. i guess not. i was just wondering. i dont need any right now. hopefully i never will.
Gen3Benz
Member
jackshafts and tons of other parts
http://www.mfgsupply.com/GoMiniAxles.html/mv_session_id=pBfsxL3S
place with cheap pillow bearings, sprockets, and chain
http://www.thebigbearingstore.com/
There are more place out there to shop around too.
cspaur13
Member
my dad wont buy from them (http://www.mfgsupply.com/GoMiniAxles...on_id=pBfsxL3S) cause they dont have paypal. i tryed to get him to order the max torque clutch. i ordered it off another site for 3 dollars more just cause they had paypal. but that should be coming in sometime this week and im gonna take the engine and my bike over to my grandpas and he said i can take some of his scrap steel,iron or aluminum to make a mount with all his machines and then he'll weld it on there. i'll have him do that sometime this week.
thanks,
cody
p.s. will my 415 chain work on a #40/41 chain clutch. i saw the comparison chart and there about the same.
thanks,
cody
p.s. will my 415 chain work on a #40/41 chain clutch. i saw the comparison chart and there about the same.
cspaur13
Member
http://www.thebigbearingstore.com/
they have there chain cheaper than any1 i've seen. might have to get some. its only 10 bucks for 10 feet.
they have there chain cheaper than any1 i've seen. might have to get some. its only 10 bucks for 10 feet.
ZnsaneRyder
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I'd recommend gearing that 2.5HP engine LOW. I know the specs are 3600, but it likes to be at 4000RPM+ in my experiences. It's a small engine, so it likes to rev.
40mph @ 3600RPM is way too tall of a gear ratio. 30Mph @ 3600 would be good. My bro's tall gearing (33.5mph@3600) with a non-governed engine gets 38mph flat, 43mph on a downhill. It's plenty fast. And we still have considered lowering the gearing for better takeoff. It's a powerful engine, but it doesn't have a lot of torque like a 6.5, so you have to gear it properly.
***You will need a jackshaft to have two ratio-reductions to get a low enough gearing***
All the bike motors use a gearbox to reduce the ratio before driving the chain. Since you are doing a DIY setup, you need the jackshaft and sprockets to basically do the same thing that a gearbox does.
40mph @ 3600RPM is way too tall of a gear ratio. 30Mph @ 3600 would be good. My bro's tall gearing (33.5mph@3600) with a non-governed engine gets 38mph flat, 43mph on a downhill. It's plenty fast. And we still have considered lowering the gearing for better takeoff. It's a powerful engine, but it doesn't have a lot of torque like a 6.5, so you have to gear it properly.
***You will need a jackshaft to have two ratio-reductions to get a low enough gearing***
All the bike motors use a gearbox to reduce the ratio before driving the chain. Since you are doing a DIY setup, you need the jackshaft and sprockets to basically do the same thing that a gearbox does.
Last edited:
Rgvkid
Member
Well i hope we can figure out how to de gov the 2.5 without breaking any components. I bought the 2 year warranty so im hoping i can put it back together so i can get a new one after the 2nd year. You gotta love the HF extended warranty .
cspaur13
Member
ZnsaneRyder
im gonna gear it low. im gonna let my grandpa try gearing it cause he would know exactly would i would need since hes had hundreds of motercycels and dirtbikes and he used to be in professional hillclimbing and he built his bikes. he might have some gear ratio calculator or something in his garage.
or i could have his make me a 70 tooth sprocket. then i wouldnt. but he'll probally make a jackshaft for me.
Rgvkid
you probally wont break anything. these engines ae way better than those cheap chinese 2 stroke kits. yea i got the one year warrenty.
im gonna gear it low. im gonna let my grandpa try gearing it cause he would know exactly would i would need since hes had hundreds of motercycels and dirtbikes and he used to be in professional hillclimbing and he built his bikes. he might have some gear ratio calculator or something in his garage.
or i could have his make me a 70 tooth sprocket. then i wouldnt. but he'll probally make a jackshaft for me.
Rgvkid
you probally wont break anything. these engines ae way better than those cheap chinese 2 stroke kits. yea i got the one year warrenty.
ZnsaneRyder
Member
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Removed the Governor for sure. The Governor is useless for a motorized bicycle, and you won't get full HP with it. 3600RPM is low for a small 79cc engine, so that's why you need more RPM to make good power. It's 2.5HP while governed at 3600, but makes more than that without a governor. I'm guessing about 3HP @ 4200RPM, but it's just a wild guess.
Also 40/41/415/420 chain all have the same 1/2" link pitch. A #35 chain is only 3/8" pitch and will NOT work. Just get a cheap #40 chain and you'll be satisfied, and it will fit.
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