300 3d max clutch mount

[Yooper42]

I'm about to install the clutch mount to the crank on my hanson 300. Is a piston stop the only thing to use for tightening this on? Also is it necessary to indicate the clutch assembly once it's on the crank for runout?

[rbort]

Do not use piston stops, you could push too hard on the piston and damage it.

What do you mean clutch mount, the stock zenoah yoke part? If you want to hold that while tightening the center bolt you can do so with a pipe wrench.

DO NOT overtighten the center bolt, its not very strong if you are a he man you can snap it, I have a strong buddy who has snapped several. Not fun when that happens.

-=>Raja.

[fastflyer20]

Apply blue loc-tite to the clutch hub bolt, I have seen a few loosen. A large adjustable wrench will also hold the clutch hub. Never use air tools, they tend to kick the crank out of true.

You could use the old trick of pushing some rope through the spark plug hole as a piston stop.

I use piston stops all the time with no issue, DDM carries them. These are small engines and must be worked on correctly for the size of the hardware being used.

[Yooper42]

Yes, the stock zenoah clutch mount, it appears Al machined the inside taper. I'll do that with a pipe wrench tomorrow. Same deal with installing the 2 clutch bolts into this yoke? Any need to indicate anything? Thanks guys!

[fastflyer20]

The taper is machined by Zenoah. The hub faces should be machined now by the modifier as some were severely out of true a few years ago. Check as it’s easy to see the casting vs a turned/true surface. It’s not required, however I like to check that both hub faces are in line with each other with a dial indicator. Worse case I see is .003”, best is .001”. The hub is tightened to the crankshaft, checked with indicator then loosened and turned 90 degrees at a time to find the lowest runout.

[rbort]

Al faces the mount points for the clutch, the inside taper is stock. Make sure it seats down before tightening it, I usually twist it a little back and forth to be sure its good. Don't overtighten, once the bolt is tight doesn't take much more force, and way less than you can manage to put on it. You develop a feel for it.

Do you have a one way that rides on top or is it just the clutch itself? I forgot what model you're building?

-=>Raja.

[Yooper42]

Yes on a one way mount. I'm building the whiplash gas v2

[jharkin]

Originally Posted by rbort

Do not use piston stops, you could push too hard on the piston and damage it.

What do you mean clutch mount, the stock zenoah yoke part? If you want to hold that while tightening the center bolt you can do so with a pipe wrench.

DO NOT overtighten the center bolt, its not very strong if you are a he man you can snap it, I have a strong buddy who has snapped several. Not fun when that happens.

-=>Raja.

+1 on the center bolt. There is a torque spec in the Zenoah manual, it’s a silly low number like 20in-lb or something. If you can buy or borrow a 1/4 drive torque wrench use it.

The bolt is weak on purpose to be a sacrificial point of failure. The torque is low enough you can wrap a rag around the clutch and hold it while tightening.

[Yooper42]

Need help here, installed clutch yoke on crank, I have the hat bushings in the bottom of the clutch as per instructions, but no matter how I stack the rest there will be some "float " in both the clutch and the one way. If I use the thicker washers I think it would go away but the ID of the washer is too small to fit over the shoulder of the bolts, still allowing some float. What's up here? Build is a xcell whip gas v2

[Yooper42]

I found Careys build log of his whip gas v2 and that has answered my questions.....

[rbort]

It is the sleeved washers that go into the clutch bottom first, as you showed in the picture. Those go against the yoke, then put the wave washers on top of the clutch and install the one way adapter on them with the bolts. You do not use the thick black washers that came with the engine clutch, those are replaced by the sleeve washers from Min Air.

Remove the spark plug and install the pull starter in the right orientation if handle is facing the rear and pull the pull start through slowly and look at the one way adapter. It should spin true to the naked eye. If you see it wobbling then you need to try to flip the one way adapter around 180 degrees and try again, and/or tighten one screw of the adapter before the other, makes a difference which you do. Also do not over tighten those screws, when they hit the stop you stop tightening. The adapter needs to float so to speak don't crank it down hard.

Delayed response from me, just came back from the field 5 more flights in

-=>Raja.