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Posted

I asked earlier about an engine builder in the phoenix area. Im looking to do a 4mill with cubs. After checking prices im a little sticker shocked. Is it that difficult to install the crank and cylinders? I am a mechanic by trade, but I work on and around 3450hp Detroit's and million pound haul trucks :miner: . That little engine makes me nervous. besides the fact I have never been in a two stroke before.

Posted

simple as pie.if you are a mechanic. follow the how to steps in here. or buy a clymers. cylinders and a crank is a walk in the park.

Posted

If your doing the work yourself, just take your time. The crank is the hardest part.... but simple still.

 

Pop off the jugs and pistons.

take off the side covers and stator plate

Loosen the bolts on the top of the case.

turn the motor over (top down) and loosen all the bolts on the bottom. in an even pattern center out.

split the case (no prying)

take out the crank

 

drop in the new one..don't forget about the locator pins on the crank bearings (some don't have any)

drop the case back down after cleaning the surface and applying yamabond #4

tighten bolts following the numbers (work them about 1-2 turns at a time so u don't warp the case)

reinstall stator plate and covers on the side

check ring gaps in the cylinders and mark them for that cylinder

ring the pistons and drop on the cub

torque all the bolts to spec TOP AND BOTTOM... then do it again after break-in (at least on the top)

 

Here is the run down as simple as I could make it. I may have left something out... follow the clymer manuel.... It will show you the correct order of disassembly.

 

Remember.... DON"T EVER PRY THE CASES!!!!!!!!!!! If it doesn't come apart with a light tap with a rubber faced mallot.... then you forgot a bolt or 3...hehe

 

Take your time. And always have the motor top down when spliting the cases.

Posted

Thanks alot turbo. That doesn't sound so bad at all. :beer: Like I said earlier. that little engine makes me nervous.

I will let you know how the project goes. Its going to be a while but it is comimg.

Where do you suggest getting the 4mill cub kit?

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