Hi,

Loking for some guidance.

1985 YB-1, 50cc 2-stroke (YB100 and FS1-E type) loses power, I suspect fuel flow or electrics but not sure.

Pic of YB-1 (not mine, mines better) here:

http://www.pbase.com/r80ks/yb1

Engine was rebuilt by local garage after imported bike was purchased.

Garage has cleaned the carb but the problem has not been cured.

I start the bike it appears to run fine, once up to speed (30-40mph) the bike will suddenly lose power. If I wait a couple of minutes the bike will start again, run for another 500yds then die again. Some days are better than others, I have run the bike for several miles on occasion without problem.

Very frustrating and I am unsure how to isolate the problem as it appears to be intermittent.

I think the garage would have to keep the bike for a few days to see the problem

Any ideas of where to start?

Thanks in advance

Mick

Hi,

Loking for some guidance.

1985 YB-1, 50cc 2-stroke (YB100 and FS1-E type) loses power, I suspect fuel flow or electrics but not sure.

Pic of YB-1 (not mine, mines better) here:

http://www.pbase.com/r80ks/yb1

Engine was rebuilt by local garage after imported bike was purchased.

Garage has cleaned the carb but the problem has not been cured.

I start the bike it appears to run fine, once up to speed (30-40mph) the bike will suddenly lose power. If I wait a couple of minutes the bike will start again, run for another 500yds then die again. Some days are better than others, I have run the bike for several miles on occasion without problem.

Very frustrating and I am unsure how to isolate the problem as it appears to be intermittent.

I think the garage would have to keep the bike for a few days to see the problem

Any ideas of where to start?

Thanks in advance

Mick

y'know what it sounds like to me? Check for water or debris in the fuel filter, it may be integral to your petrol tap.

I use clear tubing (from the hardware store) as fuel line so that I can see what my gas is doing while my bike is running.

Thanks to all for feedback.

Turns out to be too many short runs and back pressure in the exhaust.

A few good lon runs has sorted the bike out.

Now running a charm.

Mick

Here's some pic of the bike

Mick