Reving up and down

[Zed1]

Hi got a ts250/1 , got her running but not well . Starts ok but revs are all over the place ? If I start up open the throttle a bit won't just pickup but revs will go up and down all over and not just a little bit (not sure what this is called so trying to describe ).Have replaced the points , condenser ,plug and cap and cleaned the carb but still the same , any ideas where I should be looking ? Cheers

[DAVID THOMPSON]

air leaks both in the intake and exhaust and ethanol in fuel maybe... it does boost octane
but do 2 cycle engines really like it is a good question

[Blurredman]

Agree with Dave. A fluctuating Idle is indicative of an air leak of some sort.. either between manifold and cylinder or carb and manifold..

[Puffs]

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[Blurredman]

Yes in the UK all fuel is 5% ethenol, it's not yet mandatory for stations to only provide 10% although soemtimes it is available. It's more common in mainland europe to find 10% and I have tried this.. On my cars and bike I can feel a difference with 10%. Specifically the car I recall it idling pretty damn lumpy. I suppose in this aspect, adjusting the timing might sometimes rectify these.

So, from what I can tell, ethenol is not a problem unless you try 10%. And only if you use those should you be concerned for how the vehicle runs and until it was mandated I wouldn't bother.

People do find an issue with ethenoled fuel however in plastic tanked vehicle, and that includes the later MZ's. Swelling and movement of the shape can occur. I'm not really sure if there is a fix for that- at least not a viable one, other than trying to find a metal tank.

[DAVID THOMPSON]

my rt125 hates the 10% .... good way to get your 125 4t to not run
Dave

[Puffs]

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[DAVID THOMPSON]

common fuel here 10% there is an other grade for newer cars and trucks that's cheaper but takes a cut out of your power
and most do not like it

i have a electric bike from 1960 built by my dad i changed the power train the batteries are still the problem

and the power of 1 hp limit and 20 mph makes it just a way to get ran over by the low flying cars

the future is here the idiots are in charge

E100 is dangerous you can not see it burning if its on fire

[Puffs]

Correct, in open air alcohol burns with a blue flame, almost invisible.
But I loved the smell of those Beetles on alcohol in Brazil!