'08 Keeway F-Act

[captincvmn]

Changed my coil back to my original coil. The one with 200 miles on it was stumbling at sustained high rpms but the one with 6,000 miles on it works fine? 🤷‍♂️ whatever. At least it’s better now.

[captincvmn]

I have been fighting inconsistent launch RPMs and also sluggish down shifts. I took everything apart tonight to study. There was a lot of grease inside of the CVT cover and there was also grease at the bottom of the clutch bell. Apparently I over greased things. I took everything apart and wiped everything out. Reassembled with less grease and also move the pins in the torque driver to a slot that was more angled or not as parallel to the shaft. I also swapped out the black torque spring for a red torque spring. Short test drive says that it is better.

[190mech]

That sounds like me,,change 9 things at once and swear it's running better!!

[captincvmn]

Not sure why I don’t trust my temp gauge. Sitting in garage with a room temperature motor. 🤷‍♂️

[captincvmn]

But after a 20 mile ride.

[190mech]

Time to throw that one in the bin!

[aeroxbud]

Oct 30, 2021 15:17:12 GMT -5 captincvmn said:

Not sure why I don’t trust my temp gauge. Sitting in garage with a room temperature motor. 🤷‍♂️

Is the bike on fire?
If not get a Koso/stage 6, or trail tech.

[captincvmn]

She let me sit along side the road again, scratching my head. I was able to change plugs to a spare, checked spark, seemed ok-orange to blue. Sucked on vacuum hose to petcock a d that seemed stuck shut. It did open though so I held vacuum on it for awhile to see if it was outta gas. Nope. Took off air filter and held hand across the mouth of carb to flood flood the engine. That seemed to make a difference. It started but was weak and kept stalling out. After a minute of fucking with it it idled enough to put the seat bucket back and ride home. This was 20 miles into a long ride with lots of WOT 50 mph 9krpm travel. I had come out of a 30 mph corner up a hill and was at WOT to go up a grade. It just lost all ignition.

I suspect I’ve gummed another ring. I’m going to have to pull the cylinder again and clean stuff. Anybody know if the harbor fright sonic cleaner is large enough for a piston?

Anybody have any further suggestions?

[captincvmn]

Tore down engine tonight. The bottom ring is toast. Aluminum wedged against the edge of it and scuffing from the piston on the cylinder wall and scuffing from the cylinder walk against the piston. Judging by the carbon buildup on the piston there’s been some blow by. Perhaps this is normal? I’m more used to talking them apart after the wrist pin bearing grenades. The wrist pin bearing looked very good, all tight. The pin looked good too, no marks and only minor discoloration. I’m sure this set is salvageable, maybe hone the cylinder barely and ultrasonic clean the piston? I do have another set here I can put in but I’m going to get another bearing like the one I have now to use. It seems to work.

[90GTVert]

I had the Chicago Electric ultrasonic cleaner for a few years. It can easily do one of our pistons. Best use of it for me was carburetors, and I've done scoot carbs, mower carbs, weed whacker carbs... Sometimes it must find some crud that normal cleaning doesn't, because it can save a lost cause occasionally. Kinda nice for tossing a few things in there and letting it work while you do something else also. Mine stopped working properly and I bought something different that has worked better for me. Better timer setup and better cleaning. If you're considering a US cleaner, I'd consider something like this instead, in at least 3L. The brand that I have isn't sold ATM but this is basically it (Chinese stuff, you know) : amzn.to/3n0I1eJ

That said, you can usually clean a piston quite well with carb cleaner and brushing. Check it over well if you want to try to reuse it.

[captincvmn]

And we once again have a runner.
Honed the cylinder and de-gunked the piston. Worked the ring lands until I had free movement again. I have two new rod bearings on order and I’ll mate one of those to the new Corsa cylinder I have once this Corsa cylinder goes to that great junkyard in the sky.

Side note: Once this Maxima Caster 927 is gone I’ll never, ever, never, ever use any more of it. The carbon deposits it’s leaving behind are horrible and the cause of two tear downs on this engine to free up rings that were glued into the piston.

[aeroxbud]

I did warn you about the castor Rob. But we live and learn.I
Great it's running again.

[captincvmn]

i didn’t get any pictures of the cleaned piston. It’s NOT Brent clean it’s just clean enough. 

[captincvmn]

Rode a few miles on it tonight. Seems to ride ok. I was gentle and kept to 50% throttle or less. Not sure how many times I can bring this back. Now I’m wondering if I can get another stage6 70cc S/R piston and clean up that cylinder. That one has a pretty deep gouge in the wall but perhaps I can grind it out. Hmmmm

[aeroxbud]

Once you start having to grind, it needs a rebore. It's probably cheaper to get a new cylinder kit, than rebore, and new piston.