Suddenly richer?

maxi

50cc stock cylinder

biturbo

17 amal carb (overkill i know, the bike used to be kitted)

my maxi has been running very well for the past couple of months, with top speed of a puzzleing mid 40's while running a slightly rich 40:1 mixture.

Yesterday on the way home from work it started four-stroking like a mf in midrange, bogging out at full throttle, and I had to lean out the mixture just to hold idle.

So four the queston, Why would my bike suddenly seem to have these way rich symptoms, Dirty plug from from the slightly rich mixture i was using? Timing slip? What does loss of compression feel like?

thanks!

Re: Suddenly richer?

check points gap, timing, and try a new spark plug.

Re: Suddenly richer?

Thanks. Does this mean that when a moped gets richer, It is generally a spark/timing problem?

Re: Suddenly richer?

I don't think it means that, those are just the easiest things to check.

Is your air filter clean? Could be something restricting the airflow.

Dirty pipe even, maybe.

Re: Suddenly richer?

No, it could be a dirtyish carb, or your airbox/filter could be obstructed.

Re: Suddenly richer?

"suddenly richer!?"

I WISH!

lolololo

Suddenly richer?

Also, do the Amal carbs have an air/gas mixture screw? That may have rattled richer.

Re: Suddenly richer?

The screw only really effects idle, so that would not make it bogg and four stroke correct? as far as airflow, I have only a hi-flowing filter, which i actually removed completely on the way home, which did not change the behavior of the bike, so I can rule that out. Can a gummed up carb actually make it run richer? I'm at work right now (ha) ill check timing when i get home, as well as exhaust, I have been playing with that damn biturbo alot lately. thanks for all the input.

Re: Suddenly richer?

Did your weather suddenly get much warmer? That will have an effect on it as well. Sometimes you need to downjet a size or 2 for the summer.

Re: Suddenly richer?

I did think about that, I live in southern california, so the weather doesnt really change that drastically here. maybe a few degrees, but nothing big. I was thinking instead of downjetting i should up-cylinder.

Re: Suddenly richer?

yup, checking points/timing and spark plug are just easy checks before digging into anything else....start simple then if it's not that then go into carb and jetting...etc etc

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