Ebay crf230f upgrade cam and roller rockers for 165fml

[Notjoemechanic]

I've been eyeing some chinese performance camshafts with roller rockers on Ebay for quite some time that are for a crf230f. For about 50 bucks it seems like it would be worth a shot for my zs165fml motor. I'm trying to gain a little more top end grunt for highway riding. It will hit 75mph with current setup and I usually keep it to 60 or 65. I'm fine with the top speed I would like a little more acceleration for passing power when going up hills and against wind gusts and such. Anyways I'm wondering if anyone has used these cam setups with stock valve springs or have any recommendations for springs and cam timing etc.

[alex_in_az]

is the zs165fml OHC?

[Notjoemechanic]

Thats right. Its the 223cc ohc motor. From what I gather all the crf230 internals are compatible.

[Notjoemechanic]

I just ordered the ebay camshaft and silent roller rockers kit. I bought one with an "upgraded camshaft." It should be in by the end of this month. I plan on documenting the process here with pictures showing the difference between the new and old cams. I will probably do some port cleanup and possibly adjust my squish clearance if there is enough valve to piston clearance. I should gain some power and efficiency there. I'm going to steer clear of any changes to port geometry and just do a 60 grit finish on the intake side and blend any sharp edges I find including the combustion chamber. Oh and if anyone has any torque specs they would like to share or possibly point me to a reliable source that would be awesome! Hopefully this will help someone else decide if they want to try to bend a valve in their engine. I hope the stock springs hold out.

[Notjoemechanic]

Just got the cam and roller rockers in Friday. I went ahead and lightened the rockers a bit. They seem a bit chunky. Hopefully in the next week or two I will get a chance to remove and tear down the motor.

[Notjoemechanic]

I installed the cam yesterday. I still have to reinstall the motor and tune the carb. I decided not to remove the base gasket or take the middle layer out of the head gasket to adjust the squish band. It's at about .050" and I'm sure I could have but I want to play it safe for now. Reasons being the piston is already at 0 deck hight and the cam is soooooo much bigger than the old one. I also want to see what the cam will do on its own. The valves seem to clear fine when i rolled the motor over. I should have used some modeling clay and measured the clearance between the piston and valves but it was 11pm at this point and I already sprayed the gasket with copper spray. I didn't have torque specs so I just annealed the copper washers and torqued the bolts to 30ft/lbs. Im pretty sure it was hammered on with an impact from the factory because i had to use a cheater pipe to break the head loose. I set my valves to 0.006" on intake and exhaust. That has been working pretty good for this motor. Maybe next year I will tear it back down and start porting and adjust the squish. I built a flow bench so I can experiment and test results. I will probably do some more research and buy a spare cylinder head before going down that road. I did take the machinist ridge off from around the outside of the valve seats and blended it in to combustion chamber. I previously port matched the intake when I did the nibbi pwk 30 carb swap. I had to cut the flange off the intake and weld on a piece of pipe to adapt the carb and gut the original air box. I would honestly love to put the original air box back on later somehow. I hate pod filters because they are exposed to the rain. That and the adjustable cdi box alone did wonders for this bike. Anyway Im a bit off topic. I can't wait until I get it all tuned up and see what the cam will do.

[Notjoemechanic]

Well...It feels like I did a motor swap. Got it reinstalled and did a minor idle adjustment. I hit 80mph! It pulls harder through the whole rpm range. It's still a 223cc bike so dont expect a powerhouse but it is a totally different machine. It is so effortless to ride now and it feels like a bigger motor. A 6 speed would honestly be overkill if that says anything. Money well spent so far but time will tell on reliability.

[alex_in_az]

Originally Posted by Notjoemechanic

Well...It feels like I did a motor swap. Got it reinstalled and did a minor idle adjustment. I hit 80mph! It pulls harder through the whole rpm range. It's still a 223cc bike so dont expect a powerhouse but it is a totally different machine. It is so effortless to ride now and it feels like a bigger motor. A 6 speed would honestly be overkill if that says anything. Money well spent so far but time will tell on reliability.

I have a 290 degree cam swapped in mine and with the other mods I could probably hit 80 as well. I haven't done so because the bike feels really unstable at 75mph and I've not dared push it past that

[red2003]

Originally Posted by Notjoemechanic

Well...It feels like I did a motor swap. Got it reinstalled and did a minor idle adjustment. I hit 80mph! It pulls harder through the whole rpm range. It's still a 223cc bike so dont expect a powerhouse but it is a totally different machine. It is so effortless to ride now and it feels like a bigger motor. A 6 speed would honestly be overkill if that says anything. Money well spent so far but time will tell on reliability.

A cam with that much lift and duration will def get you more top end, but it will come with a significant loss of low end torque. Which is a shame as that's what the 223 was built for, and where it really shines. I'm not trying to piss in your cereal, just info for people who might be inclined to do this swap. If you ride off road, I would suggest against it.