2 stroke which one

GreasyChris

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Jan 3, 2019
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789
60+ that's wild I hoping for low 50s down hill I need it to go back and forth to work on so I need it to be reliable I live about 2 miles give or take a lil from my work so I'm thinking this will be a fun way to get back and forth I did get the steel frame and I am relatively mechanically inclined I work in the oil and gas industry so all this work I simple compared to what I usually work on as far as porting goes how much of the corners do I need to trim I really don't want to mess with timing
You can experiment with the timing by adding and removing base gaskets if your not comfortable porting. I'll have to dig out my notes on exact measurements. Port matching the intake and exhaust with skirting and ramping the piston will allow it to breathe alot better. Really you should measure your port heights and durations and get a baseline starting point and you can use a timing calculator and input your numbers and see what changes you might make will do before doing them. Was going to add the link to the calculator but it looks like the site is down
 


Juggernaut225

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Oct 19, 2019
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11
I have that same head but haven't put it on yet because I need to remove some fins to get it to fit. It will definately help with cooling. Just make sure that the spark plug extends all the way into thr combustion chamber. On some heads the plug doesn't go in deep enough and it blocks the electrode. View attachment 90891
Thanks for the tip I probably would have missed that
 

LewieBike

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May 21, 2014
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685

Juggernaut225

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Oct 19, 2019
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You know for your first engine you should probably save your money and just get a stock 66cc like from Ebay/Amazon/Walmart. There's a one-piece head/cylinder engine from Ktaxon Walmart online sells..

https://www.walmart.com/ip/Ktaxon-80cc-Bike-Bicycle-Motorized-2-Stroke-Petrol-Gas-Motor-Engine-Kit-Set/515435702

it's gotten good reviews and an inmate in this forum owns one. It will need to be rejetted much smaller on the main jet.
Well like I said in an earlier post I want something that's reliable and has a good reputation and if I spend an extra 50 bucks I'm fine with that I don't want something that I'm going to have to fix before it's even broken in
 

LewieBike

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May 21, 2014
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685
Well like I said in an earlier post I want something that's reliable and has a good reputation and if I spend an extra 50 bucks I'm fine with that I don't want something that I'm going to have to fix before it's even broken in
Reliable is relative, especially if you're going with a 2 cycle bicycle assist engine with "performance" in the descriptor.

There's a lot of half decent engines for under $160. One thing about the unified cylinder engines is that they have a very reliable reputation for upper end life. The other advantage is that these top ends were made for small implement engines and will have better castings, liner plating and larger and better matched transfer and exhaust/intake ports. You're always ahead of the game if you are not having to spend time filing and scraping on a cylinder trying "match" the transfer port openings the the base spigot of the crankcase.

When you are "matching ports and transfers", you are making aluminum and chrome plating/aluminum swarf and you have to be very, very careful about keeping any of that crap out of your engine's insides. Not one speck of that should have the chance to circulate in the new engine, because it will kill your engine if it reaches the upper end.

These are not 'performance' engines, never were. The ports and transfer design are from a Japanese bicycle assist engine made back in the late 1950's. Let's not kid ourselves, these are at best low to midspeed engines best suited for their broad power range, not screaming performance.
 

Juggernaut225

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Oct 19, 2019
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After much consideration and listening to you guys and reading endless thread I think I'm going to go with a stock zeda 80
 

Frogslayer

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Jan 20, 2019
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840
Can you buy these one piece cylinder and heads and will they fit on an "A80" China bay kit that is currently 2 piece?
 
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