A35 still smoking...

So I decided to blow off some steam yesterday afternoon on my TX-50. I swapped out the Champion L82C for an NGK BR6HS just for the heck of it. Well the L82C plug had been in there for awhile anyway. The L82C plug was black but not completely fouled.

Anyway after about 15 minutes the engine starts smoking worse. The engine seems to be loading up with fuel. It will bog down at times but does not stall. Maybe I can talk my wife into shooting a video while I'm riding it.

I enquired about a knockoff Deloroto carb a guy on Ebay sells and he suggested I do some troubleshooting because he doesn't think it's the carb. Bascially the same thing Trash Truck said could be wrong with the engine.

The reason I'm not sure it's the carb is because there are really no servicable parts inside the Deloroto SHA 14 12 P carb other than the float valve. I know the float valve is OK because I can leave the fuel on with the engine not running and it won't leak fuel. That would be my assumption. I can also turn the carb upside down and blow through the fuel inlet and feel back pressure.

Typically a leaking float valve would cause the engine to load up with fuel. Well on a four stroker anyway.

First of all let's talk about the fuel/oil mixture. Am I running too rich of an oil mixture?

I am running a 40:1 mix. I know that Tomos calls for a 50:1 mix but is that too rich for a 49cc engine? That's another story but in a nuttshell my Trabant 601 calls for a 50:1 mix but the consensus is a 40:1 mix is better and does just fine. But the Trabant has a 600cc engine.

My Kinetic TFR calls for a 32:1 mix and does not smoke! Or should I say did not smoke when it was running.

I have run Opti-2 in my Tomos which is a 100:1 mix but covers all ratios and I think it smokes just as bad with it.

The smoke is blue. There is no oil injection system on this bike. Pre mix.

Compression: This engine has a 9:1 C/R according to the manual. What is the minimum compression before the engine needs new rings?

Clogged muffler/exhaust port:

I have heard filling the muffler with Drano and letting it sit over night is better (and safer) than filling the muffler full of laquer thinner and lighting it up. Any tips on that?

Also can't find any evidence that transmission fluid is leaking into the combustion chamber. Just based on the level in the gearbox.

In summary, engine smokes worse than I would expect, seems to be loading up with fuel at times. Seems to get worse the hotter the engine.

Any other things to check for?

Re: A35 still smoking...

♣Slew Foot♣ /

ringset, check for blow by on piston sides. compression is like 70psi bare minimum to run, 120+psi for excellent, 50:1 is tomos best also regular gas 87 octane, if it has been kitted the plug needs to be hotter, tomos' dig hot plugs in the summer. i am running a 4l.

what is your main jet #? are you running an airbox? filter?

Re: A35 still smoking...

Stock engine as far as I know. I installed a K&N crankcase breather in place of the screen. That may have been a bad thing.

Wonder if it's too restrictive causing it to run rich?

I removed the K&N and started the bike up and it still smokes but have not riden it without the air cleaner to see if it does any better.

I took the carb off to measure the intake. Looks like it's 17.5mm but I'm using a plastic caliper so I'm not sure if it's actually 17mm or 18mm. The batteries in my digital caliper were dead.

Not sure about the main jet size. Since the carb is off the bike right now I might as well pull the float bowl off and check. (edited)

Re: A35 still smoking...

♣Slew Foot♣ /

14,12 dellorto sha carb, 57 jet, mesh filter. stock. the intakes id should be 12mm, 15mm od, idle setting is 4 turns out from fully closed with the throttle wide open so you do not catch the slide.

Re: A35 still smoking...

Check to make sure it's not sucking tranny oil thru a bad crank seal into the crankcase/jug.Is your trans oil at proper level.don-ohio

Re: A35 still smoking...

Yeah, I drained the fluid out and refilled it the other day with the overfill screw removed just to make sure.

Re: A35 still smoking...

That just means you have more new fluid in there to burn, what Don meant was to change the crank seal behind the clutch so the atf can't work it's way past, into the engine and burn/smoke out.

Re: A35 still smoking...

Would it still smoke at idle if this was happening? Or just when the bike was moving? Mine smokes at idle.

Looks to me like if it was burning that much transmission fluid, it wouldn't take no time to empty the gearbox out. I mean it only holds something like 300 ccs of fluid doesn't it? Looks after 30 minutes of riding, the gearbox would be empty.

Re: A35 still smoking...

So how hard is it to replace this seal everybody says is leaking?

Is the seal on the end of the crankshaft? Part #: 044 838

Just want to rule out worn rings, coked up exhaust port, clogged muffler before I tear into this thing.

By the way. I'm mecanically inclined but my time is very limited these days. Anybody know of any good moped repair shops I could send the entire engine/transmission to and have gone through?

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