The China top end kit will be fine, alot of it has to do with YOU and the install
It would be better to get Suzuki parts, Wiseco requires special break in procedure, and Pro-X is a very good piston for these, while the china kit is just so so BUT THEY DO WORK well if you install them properly

Clean the new parts to make sure no machine shop debris is left behind
Check the ring gap before you install the piston
Check the cylinder bore (all the china kits I have installed have perfect bore and the rings were in spec, but I have peace of mind since I checked before hand)
The arrow on the piston points towards exhaust
The rings seat on pins on the side of the piston, make sure they are in place when you push the piston into the bore
Dab some 2 stroke oil in the connecting rod bearings (lower at crank) and at the crank bearings (down the holes int he side of the lower unit) and at the wrist pin
Also lightly lube the cylinder walls and piston sides before install
The base gasket that comes from China is okay but you may consider re using the stock Suzuki wrist pin bearing and also the stock head gasket (metal)
Break the new top end in with a few short heat cycles to make sure no leaks and all is well
New NGK Irridium plug (LT80 says these produce a longer cleaner spark in our mini's)

DITCH the factory oil injection!! Just my opinion I trust myself to mix the gas rather then rely on the factory injection system

Good time to service your clutches (clean drive clutch variator, rollers and sheaves)

 

Thanks for the reply and tutorial!

I plan on wrenching a bit tomorrow...I'll see how it goes. I've never done a top end before, I consider this to be my 'practice bike'. I thought about taking it to a shop, but something about "give a man a fish vs. teach a man to fish" seems appropriate here.

I'm not entirely sure the stuff I took off was OEM Suzuki. It sure seems like it might have been a China kit, but I say that based on look and weight of the components.

I think I can handle the proper re-assembly. However, I am concerned about getting this one to fire up quickly, that has been a problem in the short time I've owned it.

I've read so many articles on the web about break in. Correct me if wrong, but it seems the procedure is to start it and warm it up for 10 minutes with a couple of gentle, 1/4 throttle blips. Then let it cool completely re-check torque on head bolts, repeat using 1/2 throttle blips followed by cool down, re-check torque. Repeat again using 3/4 blips then cool. Then gentle riding with no sustained throttle position.

When is a good time to check compression? Before first fire, after break in, multiple times?

I have a new NGK Iridium plug ready to go. I run them on all my other quads (two stroke and four stroke) and they have not given me any problems. I'm thinking to wait to install it until I know all is good and I won't be fouling the good plug.

As for the clutches...Maybe I will make that the next project. I'm sure I will find nastiness and need to replace a few things.

 

your warm up procedure will work fine

I do 3-4 heat cycles in the shop check for leaks, watch it run, get it warm, shut it down and let it heat soak

After that if all is well I pin it like I stole it
best way to seat rings in my opinion on a to stroke is to pin it
after a few of those then I check head bolts and compression

Usually torque is fine and so is compression

 

10-4.

I am a fan of the run it like you stole it club. That is what I was doing when I burned the last top end out!

 

Yeah...it's not a bad idea to run a little more oil for the first tank (if still on the pump just pre-mix a tank-full) and avoid long runs at the same throttle position...it's such a tiny little thing that it should seat quickly, but the above couldn't hurt...

 

First start I only let it run a minute.

 

I put it all together this morning. The reed valve that was in it was really sealed shut from junk in the fuel system. Even with the screws out to the reed I still had to really work to separate it. Only a corner would lift. I suspected that is why I was having vacuum problems.

Anyway Boyesen reeds in and top end back together. It started right up with less than 5 seconds of cranking. I ran it 60 seconds and shut it down. After a complete cool down I repeated. By the third cycle I was giving little throttle blips. After 4 cycles took it for an easy lap around the front yard. It stalled. Checked compression only 40 psi. It sounds like I snapped something in the top end again. But I do have great vacuum in front of the carb.

I think this time I will take it to a shop. More than I wanted to spend, but I looks like I don't have the proper skills to rebuild a top.

Thanks for all your help guys.

 

holy cow sorry to hear that!
I have had to do engines 3-4 times to get them right and carbs heck on off on off
Hard knocks is learning
I vote take apart see what snapped
Shop = $$$$$$$$$$$$$$$$$$$$ and time lots and lots of time

 

Yep, let's take a deep breath here.
I read back. You've done a lot of work and IMO, you can do a top end.
Take the head off and rotate the motor. Prolly end up taking the cylinder off to see what happened.
Tell us what you see. We'll help!

 

Thanks guys. I'm probably going to put this on hold for a while.

I'm coming into a busy couple of weeks with work and have a few weekend trips planned, not going to have much time to spend in the garage. Plus my youngest, who the bike is for, told me yesterday that he's tired of me always working on this bike.

Meanwhile I love the posts that come up in this forum and likely will be lurking and reading.