50cc to 85cc big bore kit installation

[justinkr58]

I have good mech. skills and know motors, if I buy the 50cc to 85 cc bolt on kit do I need any special tools or knowhow or will it all bolt on easily?

[katoranger]

I don't think you will need anything more than basic tools. Maybe a torque wrench.

Allen

[PremierScooters]

Find a gy-6 service manual. You can find them online for free to download. I found the Tank service manual 50-150cc gy-6. It should walk you through it pretty well and give you all the torque specifications.

[forchetto]

There's a very good illustrated document here, detailing the fitting procedure for big bore kits:

Look on the list on the left of the page, under "scootdawg GY6 Top End Rebuild and Big Bore Kit Guide. 16MB PDF"

http://www.scootdawg.com/page3[/b]

[bdavison]

Its rediculasly easy.
Some tips
Put it in first gear, and use a wrench to line up the tick marks. Double check all the tick marks before you close everything back up. This is so your valves are timed right.
Scrape EVERY last bit of the head gasket off. and clean it up real good before you put the new gasket on. You dont want a leak after you spent all that time putting a new engine together.
The very first thing you should do after removing the old cylinder is put a rag around the pushrod where it enters the case. That way you dont drop anything into the case. And this should be the last thing you remove before you slide the new cylinder into place.
Be careful with the clip on the piston. Those things are notorious for flying across the room...and they are hard to find.
Double check your piston rings, and make absolutly sure they are lined up right before you push it into the new cylinder.

[phil]

its not hard just make sure to adjust the valves, also be aware the kits that i have put a good strain on the battery i dont know if it was compression gains or the changing the timing on the valves as the kit includes a hotter cam