Hello Moped Army community! This is my first post, but have been on the site for months now doing research, reading the Wiki, and reading the forum posts. I've learned a lot and previously knew nothing about engines/mechanics, but now feel I have a decent grasp on how these mopeds work. However, I've hit a roadblock and am desperate from the MA community before I do a complete rebuild. Here is my setup, problem, and what I've done to date, so appreciate the help in diagnosing:
-1976 Puch Maxi (all stock except for clone carb)
-14mm bing clone carb
-64 jet w/ 2.22 atomizer (stock)
-Stock air box
-Won't idle / dies when trying to idle even with idle screw all the way in
-Fouled spark plug (wet with oil)....I've burned through 3 spark plugs trying to diagnose with the same results
-Heavy white smoke from exhaust that won't go away, even after clearing the engine as described here: https://www.mopedarmy.com/wiki/Clearing_out_your_engine
-Black oil substance coming out of exhaust when WOT trying to clear out engine. Oil just keeps on coming out, but very slowly.
- Used to go 30mph no problem and have pretty good acceleration, now tops out inconsistently between 20-30mph and accelerates more slowly
- Also, all these problems occurred overnight. Rode it one day working just fine and then the next day took a turn for the worse. The only "odd" thing I did the last day it worked great was let the bike idle for like 10 min after initial startup, hence why I tried to clear out the engine due to possible oil build-up.
What I've Done
-Removed all rust from gas tank
-New fuel lines and inline filter
-Totally cleaned out the carb and all components. Adjusted float needle slightly with same results.
-New O-Ring between intake and carb
-New gasket between intake and head
-Drained ATF and installed new ATF with new gaskets (ATF was pretty low and a brown/maroon color)
-Replaced spark plug 3 times (same results). Bright blue when new and after clean, but not much spark after it gets fouled up obviously. The only time I can actually get the bike to idle is with a brand new plug for the first few minutes.
-Removed head to clean piston, cylinder, crank, check & set cylinder rings, etc. (Note the crank and inside of the piston area was pretty wet with dark oil, which I believe to be the source of my consistent fouled plug)
-Removed and cleaned entire exhaust manifold, pipe, and muffler. Installed new gasket at intake to head and new gasket at intake to pipe.
-Headlight, tailight, brake lights, and horn all work just fine
My diagnosis of the problem is that I have a bad crank seal on the right/clutch side and ATF is getting sucked into the engine based on how oily my crank/piston was, my consistent white exhaust smoke, low ATF fluid, and fouled plugs. Hence the no idle, poor acceleration, and low top speed. Also, when I've tried to clear out my engine a couple times (with no results) it seems to get very hot, have a unique smell, and my brand new gasket between the intake and pipe fell apart on it's own, so something isn't right there.
The only things I haven't done yet are clean the points and adjust timing. That was actually next on my list of maintenance to do on the moped, but then this whole problem happened and I got sucked into doing everything else first.
Does anyone have any other suggestions to try first? I really don't want to have to remove the engine to get to the crank seal, but if it's my only choice I guess I'll have to. I'm sure I can figure it out with the wiki, photos, YouTube, etc., but just considering it a last resort since it's an undertaking.
Sorry for the long post, but I know you guys ask a lot of questions so trying to put it all out there initially. Please help me! Thanks MA community.