Engine Replacement!

[solomon]

I have a honda cr80 and the piston blew. And the bottom end is full of piston chunks and cylinder is shot, i really dont want to rebuild. What would be a suitable replacement engine? im on a 300 dollar budget

 

[residentg]

cr80 and cr85 require frequent ring changes. your cheapest option is to simply replace the piston and rings on your existing engine. it is a 2-stroke, so you do not need to worry about metal in the transmission, just blow out the metal in the cc. you may need to have the cylinder bored to the next oversize, unless it is wasted, then you may want to scrap it.

 

[solomon]

well it blew up and upon inspection i found there are chunks of metal it the ottom end and th piston is missing a huge chunk, the ring was fried and the cylinder has a deep wide scoring mark on the top of it. So i figured, 30 for gasket set 70 for rings and piston, 40 for clutch (might as well rebuild it), but i think have to bore it out. How much does boring it out cost?

 

[Rickracer]

If the bore is too far gone, you can find cylinders on Ebay.

 

[EagleTalons]

Can't you just press the sleeve out of those?

 

[Rickracer]

I'm not sure, but most sleeves are like $40~$50, then the machine work, still gotta be bored, etc. It's worth investigating anyway,

 

[jr dragster T]

I just rebuilt a 2005 CR85R top end. A base gasket, Head gasket, Piston, Rings comes up to a whopping total of $84.

 

[solomon]

yeah sounds about right, its just that my piston blew! so i have chunks in the bottom end so thats another 30 bux for the gaskets plus my swingarm bolt is stuck and isnt coming out so who knows. And a sleeve is around 100 bux. No cylinders on ebay for under 100 bux in good shape =(

 

[oscaryu1]

http://cgi.ebay.com/ebaymotors/HOND...7543320QQptZMotorcyclesQ5fPartsQ5fAccessories

Go find an appropriate piston for that and use it...

http://cgi.ebay.com/ebaymotors/Hond...7760125QQptZMotorcyclesQ5fPartsQ5fAccessories

Few nicks but looks OK...

http://cgi.ebay.com/ebaymotors/hond...6341651QQptZMotorcyclesQ5fPartsQ5fAccessories

What year is it again?

http://cgi.ebay.com/ebaymotors/1983...9067193QQptZMotorcyclesQ5fPartsQ5fAccessories

Great cond, $50 buy it now.

Look a bit harder next time

 

[solomon]

hah too bad those are all auctions ad too bad the last one needs a head too. Mine uses a 5 bolt pattern. anyway im junking the bike. I bought 2 gas scooters

 

[jr dragster T]

Your junking a motorcross bike for gas scooters? Hell ship me the bike!

 

[BriggsTwins]

General MAchining on a bore PROPERLY DONE will run you about 150$ can you measure the scratch in the cylinder and give me an idea of how deep it is? has the engine ever been bored? check the cylinder from the head view, look for the line where the sleeve is pressed in, and see how much material is there.
If you can do it yourself do not forget your cross hatch pattern!

 

[BriggsTwins]

General MAchining on a bore PROPERLY DONE will run you about 150$ can you measure the scratch in the cylinder and give me an idea of how deep it is? has the engine ever been bored? check the cylinder from the head view, look for the line where the sleeve is pressed in, and see how much material is there.
If you can do it yourself do not forget your cross hatch pattern!