Counter shaft motor, is it good

[Skip_200gy]

I've seen some shops selling bikes with counter shaft motors. You can recognize them by the extra piece under the exhaust port.
Does anybody have such a motor in their bike? Is it much better?
Is it based on any well know motor?
The price of the bike with that motor was about 20% more than mine and it did not have a rev counter ,upside down shocks or back disc brake. I did not think it was worth the price.
I also felt much safer buying the bike with the more recognized motor.

Sorry, I can't find a picture now.

[Jim]

Here's the picture

[img]/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=7252& g2_serialNumber=1[/img]

I've had both the non balanced and now the balanced motor... I would definitely go with the balanced one, I haven't gotten too many miles on it yet, but it is amazingly smooth, it's not really broken in yet, but I would say it has as much power as my other one had so no issue there... Granted I am not a dyno, but if I had the choice I would always pick the balanced one... From my experience.

[Dragon]

nice gy6. When will it be available in the States?

[usmc-mustang]

I currently have both. The non CB motor on the Viva, and a CB on the JetTah. The only real difference I have seen, it that the CB motor has more gear noise. Both are pushrod motors. Maybe in the OHC motor the gear noise is not noticable, as the cam is driven by a chain rather than by heli cut gears.

[Jim]

I don't think they are planning on getting the gy6 in the USA, at least A.L. isn't and I haven't heard anything about any other distributors getting it, but who knows maybe it is there already from someone?

[cresstt]

i got a 150 counter balanced motor and then i made a mistake of removing the counter weight when I was overhauling the engine. The bike wihtout the shaft is still okay, a lot more power but then you'll also get vibration at high rpm.

My other 200cc zongshen engine which I'm changing timing chain at the moment is without the balancer mechanism and I tell you, it vibrates like crazy!!! if this engine has the same mechanism that my 150cc has, i could go faster as there is more high rpm to play with.

[cresstt]

There are a couple of pics of the balanced engine and the balancer weight

http://chinariders.net/modules.php?n...&t=359&start=0

well, i am not sure. for the first 500 kilometers my bike was as smooth as silk, since then there is a recurring vibration. I got rid of it once by tightening the back engine bolts and locktighting them, but the vibration is back pretty good now. I just accept it.

does anyone know what would be the symptoms if the counterbalancer were to fail?

[cresstt]

Originally Posted by zapkin

does anyone know what would be the symptoms if the counterbalancer were to fail?

when the bearings go south, it would make sorta like grinding and clicking noise. . there is no maintenance on this thing except for the two side bearings. If let say the balancer weight itself disintegrate, crack and falls apart, then you would definitely feel the difference. The ride would be like sitting on those message chair. there'd be extreme vibration, up to the point that the bike is not ridable anymore.

another related maintenance issue is that, the balancer setup would require a different oil pump driving mechanism. On the non balanced engine, the oil pump is directly driven of a gear on the crankshaft. On the balanced engine, the centrifugal oil pump is driven by a chain (like the timing chain, only shorter) connected to a gear of which is driven directly by a cog on the crankshaft. I had to replace mine after 2 year of daily 40 miles riding, as the chain has stretched and was grinding part of the oil pump chain shield.

that is good news for me. thanks for reply.