Tomos a35, four stroking at 3/4-wot. Now bogs

Wesley Burson /

My a3sl runs good but if you go past 1/2 throttle in sexing gear it will four stoke and lose power. After riding for about 1 hour I turned it offf let it sit went to start it and now it bogs at any throttle?

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Check for dirt in the jets or emulsion tube or fuel plugged some way.ALSO a spark plug going bad will do that. don-ohio (:^)

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Wesley Burson /

It also smokes horribly

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Hmmmmm.smokes bad,eh? Could be a crank seal suckin'in tranny oil and air.Check the fluid level in the trans. don-ohio (:^)

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Wesley Burson /

Thing is it worked fine till I shut it off for 15 min

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Okay,I'd try shutting off the petcock when you shut off the bike.Make sure it's not dripping fuel into the exhaust. don-ohio

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Wesley Burson /

I tried to perform a plug chop. The plug was black and wet. To rich? I'm running the stock jet. Should I down jet or could it be the cdi?

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Plug black and wet means bad spark or fuel leaking thru or too much oil in fuel or low compression. Have you checked the tranny fluid level like I mentioned above,to make sure it's not inleaking oil and air? don-ohio

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Wesley Burson /

I'll check when I get home

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

A lot of mopeders have found that seal to be their problem(including me on an MO2,so it's good you'll check. don-ohio (:^)

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Wesley Burson /

Exactly what seal are we speaking of?

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Wesley Burson /

We're sit located

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

It's the rightside crankshaft seal behind the gearset in the transmission.When it goes partially,the engine will run,but foul plugs and the trans oil is usually very low after a while. don-ohio

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Wesley Burson /

How do I check if it's bad?

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Re: Tomos a35, four stroking at 3/4-wot. Now bogs

`Leak down` test is how the pros do it. I just look at the plug and if it's pretty dark and runnin' bad and I'm losing fluid from the tranny,I replace it.

I've only had the one go bad that I can remember. don-ohio

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Wesley Burson /

I removed the trany side seal. How can I tell if it still good? Thanks again don!

image.jpg

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Just assume it's bad now. You don't want to reuse it.How much fluid was in there?Did it smell anything like fuel? Here's a link on this site from a search I did.

https://www.mopedarmy.com/forums/read.php?6,1781952,1781976#msg-1781976 hope it works. don-ohio (:^)

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Wesley Burson /

Is it suppoed to sit flush with the crank port? It was stuck out quite far. I was able to remove it with a fingernail!

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Wesley Burson /

Tried a new seal. No dice but it does spit oil out the pipe?

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

You could pull the seal with your finger? It's bad then. Usually have to get a screw into them or a hook and pull `em out. Most seals sit flush or farther in. don-ohio

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

♣Slew Foot♣ /

check ring set for blow by, it would smoke.

a35's have a bad habit of blowing the seals because the case side support bearing goes south then when run like that it spreads the seal into an oval.

marvel mystery oil will swell the seal if it isn't too far gone. alot of folks will tell you to overfill the tranny for racing....

it runs fine with just 5oz, it calls for like 7oz. if overfilled, it spits it out the sprocket seal givin you the black wheel of death.

run a piece of pantyhose instead of the restrictive airbox or metal mesh disc. if it clears up, downjet and replace filter.

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Wesley Burson /

The seals are good and the bearings are good. I removed the air box and now it has a bit more power but now the carb is loud. That's right the carb. What the hell am I doing wrong?

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Don't remove the airbox,tune in the amount of air that gives you a good plug chop. You need the breather to prevent seizes. don-ohio

Re: Tomos a35, four stroking at 3/4-wot. Now bogs

Wesley Burson /

i figured it out and it was so dumb. the jet unscrewed its self just so the jet was blocking its self off with the bottom of the bowl, but still sealing the jet threads. tightened it up and it works. ever since i replaced the seal it no longer 4 strokes!

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