Correcting transfer angles, bearing upgrade, and case stuffing

[Jayraye39]

So im going to document my attempt at correcting open transfer port angles, bearing replacement, and stuffing the case.

First off I have never attempted to breaking down the entire bottom end. Ive watched people do it and read up on it aswell.

It was kind of discouraging, because most of my research told me it was difficult also said you need special tools like the little gear puller that come with motor kits.

Well I do not own a fancy gear puller. But what I do own is the confidence and problem solving skills required to do the job using only hand tools.

To my suprise the tear down process was very simple. In fact took me about 25min. To get the gears off i used a small tire iron pry bar and a flathead screw driver. Basically i put the pry tool under either side of the gear and put even pressure till they poped off.

This was just step 1 but somehow I think re assymbling is going to be the hard part.lol

 

[weefek]

Assembly is the fun part.

 

[Risk Man]

So im going to document my attempt at correcting open transfer port angles, bearing replacement, and stuffing the case.

First off I have never attempted to breaking down the entire bottom end. Ive watched people do it and read up on it aswell.

It was kind of discouraging, because most of my research told me it was difficult also said you need special tools like the little gear puller that come with motor kits.

Well I do not own a fancy gear puller. But what I do own is the confidence and problem solving skills required to do the job using only hand tools.

To my suprise the tear down process was very simple. In fact took me about 25min. To get the gears off i used a small tire iron pry bar and a flathead screw driver. Basically i put the pry tool under either side of the gear and put even pressure till they poped off.

This was just step 1 but somehow I think re assymbling is going to be the hard part.lolView attachment 192521

Is this the engine off of your new build or a spare?

 

[ImpulseRocket]

New engines tend to come apart easy. Try again on one that has a few years and thousands of miles of grit, grime, and corrosion. That's when they really start to put up a fight.

Re-assemly is fairly easy.

Just make sure to keep things clean when you re-assemble.

 

[GW's Motorized]

If you have a harbor freight near by I'd suggest you pick up a handful of magnet trays. Those are the best when trying to keep track of bolts

 

[ImpulseRocket]

If you have a harbor freight near by I'd suggest you pick up a handful of magnet trays. Those are the best when trying to keep track of bolts

ziplock freezer bags and a sharpie marker also work well.

 

[GW's Motorized]

ziplock freezer bags and a sharpie marker also work well.

I like the magnet tray because I can clean the bolts with a degreaser while they are there

 

[ImpulseRocket]

I like the magnet tray because I can clean the bolts with a degreaser while they are there

I can fill a freezer bag with degreaser and do the same thing, and with less effort

 

[Jayraye39]

Is this the engine off of your new build or a spare?

This is a spare I got off someon it said it was a pk80. It has the old lmn 40 crank 40mm stroke hybrid. Im also gonna case match. Just waiting on a new jug and piston the guy before me didnt clean the jug castings inside and the whole top end is scored deeply inside

 

[Jayraye39]

I corrected the transfer port angles and the motor shows no noticeable improvement what so ever. To me its a mod that really isnt needed. just grind directional ramps on your piston crown. that works mutch better