Iffy sputtering from moped during break-in period

Rowan Vannier /

Rebuilt my first e50 and installed the 72cc airsal kit. I have been breaking in the kit for about 1-2 weeks right now and everything has been great so far. However, tonight, I was riding the moped home today in the rain and I cracked into WOT. About 3 minutes later, my moped started sputtering and bogging so I pulled over. My engine (at spark plug) did not reach more than 270 degrees Fahrenheit. It was kinda sketchy and I thought the piston ring got caught on a port (even though I smoothed out all my ports). FYI I am also running no air filter on my carb (if this has anything to do with the sputtering). I ended up riding the ped home at like 15-20 mph.

If anyone know what possibly happened just holla,

thx <3

Re: Iffy sputtering from moped during break-in period

timing slipped? air leak? too rich? too lean? did you check your plug?

Re: Iffy sputtering from moped during break-in period

Rowan Vannier /

I have not checked timing but Last time I check I have no air leaks and I’m running pretty rich. I will double check the air leaks and timing.

Re: Iffy sputtering from moped during break-in period

I would say it is all there in the post. Riding in the rain with no air filter would be high on the list.

Re: Iffy sputtering from moped during break-in period

Rowan Vannier /

Okay. I wasn’t sure if that would really affect the carburetor or not. Thanks tho.

Re: Iffy sputtering from moped during break-in period

Dirty30 Dillon /

Riding WOT in the rain, no filter, the chances of you sucking up a nice gulp of uncompressible water is pretty high. There's a lot of variables, as Daniel stated tho

Re: Iffy sputtering from moped during break-in period

Rowan Vannier /

Checked for air leaks and timing and everything was fine. Even cleaned out the carb. I was riding it again and cracked into WOT. A couple minutes in it sounded like something in the cylinder was scraping and the moped sputtered and slowed down. I pulled the head off to look inside and everything seems fine to me. What yall think???

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Re: Iffy sputtering from moped during break-in period

sieze city

Re: Iffy sputtering from moped during break-in period

Rowan Vannier /

Just got it running again and it seems fine. I just let it idle and blipped the throttle. Is the kit actually toast?

Re: Iffy sputtering from moped during break-in period

Matt Mahloch -- MBM Customs /

How are you establishing the CHT? Temp gun when you pull over or trailtech or what?

Cylinder is fine. The flash/light makes it hard to tell how bad it is. Worst case new piston ring and 1500 wet sand with wd40 to clean it up. Then wash it with soap and water and a brush prior to reassembly.

Does your carb sit forward so rain is getting pushed into it? If it does probably not the best but if it’s rear facing I wouldn’t worry about it.

You can’t have many miles on that thing as clean as it is. Is the timing proper? Was it really minutes at WOT or more like 20 seconds while increasing speed? If the later I’d guess you’re rich on the main.

Is your cylinder setting down all the way on the cases? That’s a huge gap between the piston and bottom of the ports. This isn’t a big deal but something to take note of. It’s not causing a problem but you’re leaving a little power on the table.

Re: Iffy sputtering from moped during break-in period

Sputtering could just be from your electronics being wet

Re: Iffy sputtering from moped during break-in period

> Graham Motzing Wrote:

> -------------------------------------------------------

> Sputtering could just be from your electronics being wet

You don't really think that electronics soaked in water would really effect it at all , do you ? LOL

Re: Iffy sputtering from moped during break-in period

if you can feel the scratches w your fingernail its bad. Are u running any oil?

Re: Iffy sputtering from moped during break-in period

Rowan Vannier /

Responding to a couple of people here:

I have the trailtech temp gauge.

My carb faces the rear wheel (it's just the stock bing carb + intake)

The kit is VERY new, about 1-2 ish weeks of breaking it in. The timing is at 17 degrees or mm. It was also probably sub 1 minute at WOT before the moped sputtered and I heard something scrape.

The 72cc kit that I have needs to have a higher deck height to accommodate the fact that the piston will hit the head of the cylinder. I am running 3 1 mm metal gaskets, but I can always lightly sand at them to make the height a little less.

I also have my electronics heavily wrapped in electrical tape. I find it hard to believe that they got wet, but it is still possible I guess.

ALSO... the inside of the cylinder is still very smooth and I cannot feel any scrapes or such. I am running a 50:1 ratio of gas to synthetic oil that I bought at O'Reilly's.

Thanks all

Re: Iffy sputtering from moped during break-in period

To lean on the oil! Run it at 40:1 or even 32:1 for the break in!

Re: Iffy sputtering from moped during break-in period

What size Bing and Jetting you got?

Is it kinda four stroking if you go from WOT to like 90% throttle?

I was breaking in that same kit (diff carb) this past summer and it was suprising to me how big of a main jet it needed to be happy at full throttle and high rpm.

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