Drop-in 279cc engine for the RX3?

[SpudRider]

Originally Posted by rtking

I don't think this big bore kit is meant for use with the ZS177 engine, unfortunately. Our bore is 77 mm, so to get to 300cc, you'd need to go with a 84mm overbore and a custom piston.

Originally Posted by Eco Mouse

Would it really matter what the new bore is vs. the old? When they are giving you a new sleeve, and piston to match? Obviously, if the bolt holes and water passages don't line up, that's an issue.

Would this make it more of a stroker? Maybe what's missing is a longer connecting rod?

RT is correct. This cylinder is not part of a big bore kit for the ZS177MM (NC250) engine. The bolt holes, lubrication journals, and water journals do not line up. This kit is designed for a 250cc ATV engine. I don't know of any big bore kit for the RX3 engine.

Here is a photograph of the ATV, big bore cylinder.



Here is a photograph of the RX3 cylinder.



The RX3 cylinder photo was taken from the following thread.

http://www.chinariders.net/showthread.php?t=15591

[Eco Mouse]

Well, I guess that makes my decision easy... Turbo it is!

[Jay In Milpitas]

Originally Posted by SpudRider

. The bolt holes, lubrication journals, and water journals do not line up. This kit is designed for a 250cc ATV engine.
Here is a photograph of the ATV, big bore cylinder.



Here is a photograph of the RX3 cylinder.



The RX3 cylinder photo was taken from the following thread.

http://www.chinariders.net/showthread.php?t=15591

Not to mention that it would be a real pain trying to route the cam chain through the pushrod tube holes.

[SpudRider]

Originally Posted by Jay In Milpitas

Not to mention that it would be a real pain trying to route the cam chain through the pushrod tube holes.

Indeed. I have never worked on a pushrod motorcycle engine, but I noted the cam chain well did not extend completely through the cylinder.

[Skyteamst90]

Its too bad there isn't a 300cc or so enduro. Maybe there is one out there, but I am new to this, so maybe I haven't found one yet.

Originally Posted by SpudRider

I think I would rather wait for the RX4 with the 450cc engine, which Zongshen plans to introduce next year.

http://www.chinariders.net/showpost....postcount=4969