no going back, now, motor out!

[Neil955i]

Hawk how frustrating is that?!  All that work and NO moment of revelation? Just hope it goes back together well & no more filings - or shaking.

[Stig / Major Tom]

I'm saying this in complete honesty.....
I did not think that there was an internal mechanical issue with this engine...as described.
But, I was certain that the Hawk was going to enjoy taking it apart.

I may or may not be right about the former, but I'm pretty confident about the latter.
Another member recently admitted that it may well be that he enjoys working on his scooter..at least as much, if not more than - riding it.
There are 3 here who come to my mind....
Absolutely 💯 % nothing the matter with that!
Stig

[Iahawk]

I'm saying this in complete honesty.....
I did not think that there was an internal mechanical issue with this engine...as described.
But, I was certain that the Hawk was going to enjoy taking it apart.
Stig

Well I was sure hoping to find something in there but there was not a single flake of metal to be found and no excessive wear...and Stig, you're spot on...I've always wanted to tear one of these motors apart to see how everything goes together! Kind of a win-win, so far. No major engine problems and I get to disassemble and reassemble the motor!

After watching many youtube videos of guys (mostly in India?) restoring old, rusty Honda scooters and motorcycles I have no doubt these little motors are all but bulletproof - (and our little GY6 motors are based on old Honda designs, right?)

What better Father's Day gift than to get to assemble a scooter motor in the garage!

[Iahawk]

all right, all set up..took about 40 minutes to get the garage set up and all the parts and tools brought up from the basement. Crank is in the freezer, hopefully shrinking a tiny bit. Had to run out to get more blue threadlocker.

Now waiting another 30 minutes for crank to freeze and will heat up motor case and crank bearing should slide right in.

Here's a few pics of all the parts laid out.

[Ruffus]

Looks good! Suspected from beginning this camshafts being improperly cleaned (sandblasted) after casting.

[Iahawk]

OK, success so far! I spent a 'perfect' Father's Day in the garage listening to music and assembling my scooter engine. For a rather introverted gearhead like me..that really is a perfect day.

Started with the crank in the freezer and heated up the case. Crank went in fairly easily (you can still see frost on the crank). Then I added the gasket and heated the right case and slipped it over the crank and bolted them together.

put the piston on the con rod, installed cylinder gasket, made sure the rings were all clocked correctly and slipped the cylinder on. This was the hardest part of the process, getting the d*mn cylinder over the piston...I ended up compressing 1 ring at a time and slowly working the cylinder down.

Then put on chain tensioner (with new gasket and o ring under screw). Installed starter and put in oil pump and oil pump chain.

[Iahawk]

starter gear and starter clutch with left hand thread starter clutch nut

got the outer case on and the stator and the wiring all positioned properly

then installed flywheel and fan

[Iahawk]

installed headgasket and head...then got motor to tdc and installed cam under the cam chain, installed rockers and torqued everything down

adjusted valves...10mm intake and .12mm exhaust..edit - crap - questioning my valve adjustment, now. I  did .10 and .12 inches instead of mm. Will need to redo it correctly..added to my list...

installed head cover and spark plug

[Iahawk]

...and after about 4 hours, total, the motor was reassembled...and yes, it does rotate!

Last step was installing the 3 pieces of the black plastic covers for the airflow.

I still need to add oil, so don't let me forget that step! I'll work on getting it back in the scoot over the next few days.

It was a very satisfying feeling when I put the last cover on..knowing I'd completely disassembled and reassembled my motor.  It was 4 1/2 months ago when I first started tearing into the motor. That's too long to be without my S200!

[Iahawk]

OK, 10 minutes later the valves are correctly adjusted. Easy job, especially with the motor out of the scooter!

.004" / .10 mm for intake and .005" / .12mm for exhaust.

Here's a pic of my tool I use to hold the adjuster, it's just a square head wood pocket screw bent at a 90 degree and wrapped with some electrical tape. The square head screw fits on the adjuster perfectly.

[Iahawk]

spent from lunch until dinner time putting the scoot back together. A little challenging to do it alone..a 2nd pair of hands would have been helpful in positioning the motor, but I got it done. Hooked everything back up that I'd take apart...and it was a LOT...but I think I have all fasteners fastened, all electrical connections connected and all vacuum lines installed. Pictures were helpful (that I'd taken during disassembly) for routing the electrical connectors, etc. The 2 toughest parts were installing the rear brake line bracket under the cvt (for the life of me couldn't figure out how it went..finally got it installed) and installing the exhaust. I've had trouble with the exhaust in the past and other times no trouble at all. It's the rear 2 bolts where the exhaust attaches to the swingarm..tough to get it lined up.

Before motor installation I pulled the carb and cleaned it...would have hated to go through all this only to discover the carb was dirty and affecting the running of the scoot. Sucked it up and did the cleaning. Fresh fuel, added oil to the oil-less engine, charged battery and started her up. Took about 3 pushes of the start button to get fuel to the carb...then she fired up and idled smoothly.

Rain interrupted my progress this evening so I'll aim for an early (not Stig early!) morning ride.

Oh, and I wiped the whole scoot down with detail spray using a clean microfiber...so she's lookin good!

[Stig / Major Tom]

Great job Hawk!
Thanks for taking us along.
Pictures please?

Stig
(last run to the Gulf....03:53am)

[Iahawk]

thanks, Stig. I only took a couple pics during the 'rebuild'..here's one that shows the plastic-less and motor-less scoot. I think I'm holding the auto bystarter cable in the pic. Next pic is of the final product..assembled and ready to go.

I did end up taking a short (9 mile) ride last night. Turns out I was out of beer plus the scoot only had a quart of canned tru fuel in it, so a trip to the gas station and beer emporium was in order. I try to minimize the time I leave a cold 6 pack under the seat as that heats up pretty well.

I went out around 8:30 with cloudy skies and mist..it even lightly rained on me very briefly during the ride but it felt good as the day had been so hot. The scoot felt....great.  It has been 7 months since I'd ridden it and I forgot how great it feels around town.

It is perfect up to about 45 mph, then the ride gets a bit jittery. The sweet spot is from 25-40. Such a different riding position and feel from both my Ninja and my Helix.  Still felt great..kind of like getting back with an old girlfriend..it just feels right.

[Iahawk]

Great job Hawk!
Thanks for taking us along.
Pictures please?

Stig
(last run to the Gulf....03:53am)

wait, I just noticed your posting time, too...you're up early even for you, right??

[Ruffus]

Great hawk, congrats!👍👏