CB250/ZS169 optimum valve lash setting?

[crackerjac]

I've read numerous threads and searched and there is seems to be a number of recommended setting for the valves on the Zong 250 (fake 169mm) motors.

What is the best recommended setting for intake and exhaust valve lash on these motors?

[humanbeing]

Honda said in/ex: 0.1mm for 65.5 * 66.2. Don't listen the hoax 0.05mm B$, otherwise will ended up as those sad Skyteam V-Raptor story...

[crackerjac]

Originally Posted by humanbeing

Honda said in/ex: 0.1mm for 65.5 * 66.2. Don't listen the hoax 0.05mm B$, otherwise will ended up as those sad Skyteam V-Raptor story...

Awesome thanks!

Another question for you and I'm not sure how to really explain it. How far into the crank shaft should the flywheel go? I installed it and used my impact it went so far and the f'b bolt snapped! I'm beyond mad right now. The flywheel doesn't seem like it's on far enough to me and the starter ring (whatever you call it) has what seems to be a lot of space between it and the inside stop on the crank shaft. Is it suppose to be free floating like that?

[Rangerscott]

I googled honda crf adjustment and each site ranged from .003 to .005 in so I went with .004" on both sides.


Both sides were tight on my engine. Still could tap them but no where near .004".

[Rangerscott]

Ouch on the bolt. I always try to find torque specs or if using N air gun, a couple quick pulls on the trigger and stop.

[crackerjac]

I got extremely lucky and with a little effort, and a screw driver, was able to catch an edge of the broken bolt and unscrew the piece in the crank shaft. I was amazed.

Does anyone know what size this bolt is? I'll assume grade 8 fine thread metric size what?

I looked at the crank shaft and the flywheel. The flywheel opening tapers down smaller than the crank shaft size so there is no way the flywheel goes all the way flush. It just seems weird that the one way starter gear can move in and out about half an inch perhaps. Doesn't seem right.

[crackerjac]

Damn it are the starter clutch and gear suppose to be one piece or two?? Mine are separated but looking at a few threads here it would appear they are one? But than looking for parts mine are exactly like the ad posted on Aliexpress.com so what I'm I missing? Are they one piece or two?

http://www.chinariders.net/showthrea...t=14262&page=2

https://www.aliexpress.com/item/ZONG...08.4.28.9oGKmx

[Rangerscott]

I'll try to start taking mine apart tomorrow for you.

[Rangerscott]

Here's some pics of mine. There was 4.85mm gap from end of crank shaft to bolt head.

[Rangerscott]

There is a special washer with slots that goes under the flywheel/starter gear.


Mine is just like the aliexpress link too. Stator wheel, then 3 allen bolts hold starter clutch wheel, then starter gear just slides on the rear.

[crackerjac]

Originally Posted by Rangerscott

There is a special washer with slots that goes under the flywheel/starter gear.


Mine is just like the aliexpress link too. Stator wheel, then 3 allen bolts hold starter clutch wheel, then starter gear just slides on the rear.

Thanks for the pics. I'll take a measurement as see how much mine differs. Does your starter gear itself have a bit of movement inward and outward?

Found another bolt. M10 fine thread.

So i put it all together and taken it apart a few times and still have about 3/4" that the starter gear can move inward and out. Seems to be the way it came. Only issue seems to be that when the gear moves all the way inward the teeth of the one way bearing are just barely on the hub and occasionally slip causing the starter to not engage. I do have the spacer behind and the one in-front that is sandwiched between the gear and flywheel.

I'm tempted to add an extra spacer washer behind to prevent the gear from moving back as far as it does hopefully eliminating the slipping issue. It's as though the flywheel should be further back on the shaft but can't. When the gear is moved closer into the one way bearing it works perfectly all the time and seems to line up better with the smaller starter gears on the side. Feeling frustrated.

[Rangerscott]

I'll try to make time to get some more pics and vids. Probably will be this weekend.

[crackerjac]

Originally Posted by Rangerscott

I'll try to make time to get some more pics and vids. Probably will be this weekend.

Thanks, I do appreciate all your help on this.

I ended up putting one spacer washer behind the flywheel to take up a little bit of space and hopefully help engage the one way gear better. Hopefully I haven't screwed myself by doing that.

Anyway, it's all back together other than a few questions I have on timing marks etc. but I'll start another thread for that.

Hope you don't mind but I'm going to use one of your photos above for reference for a question on another thread?

[Rangerscott]

Hope this answers your question.

[crackerjac]

Thanks for the video. Interesting that mine has more space behind the starter gear yet setup the same way. One thing I noticed was you are missing one spacer washer from your setup. There is a second washer that looks the same as the one that goes on the crank first but this washer is thinner and meant to space the starter gear away from the flywheel just enough so it doesn't rub on the assembly. See pics below.