Roketa MC-54-250B Stalling when stopping (FIXED 09/28/08)

GOOD NEWS: As of 09/28/08, it is running great again!!!!




It was a valve issue.

Both the exhaust and Intake valves were totally mis-adjusted. While at TDC, both valves had no gap.

Thanks to the information and pictures posted on ScooterDawg, I was able to resolve the valve issue by adjusting the valves..

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Original post:
This is the first of two MC-54-250B scooters we purchased. It has 1730 miles on it since early July 2008.

Until recently it ran great. Then it started to stall every so often when stopping. Now it stalls at every stop.

I have concluded it actually stalls when the engine has to wind down quickly to moderately such as when on the kickstand forks and you rev the engine to spin the tire and then release the throttle and apply rear brake while engine is reving down.

The video shows the engine:
- starting
- reving up and down without braking
- reving up and down while rear braking
engine stalls
- hard restarting after stall

I have replaced:
- All Fuel hoses
- All Vacuum hoses
- Fuel Filter
- Vacuum fuel pump w/12v Electric Fuel Pump

I tried:
- Adjusting the idle
- Adjusting air flow (screw on bottom of carb)
- Cleaned air filter
- Changed oil and gear oil at 500, 1000 and 1730 miles.
- Swapped electronic automatic choke from our
other new working MC-54-250B
The choke looks like a black cylinder with a needle inside
- Placed choke back in new scooter's carb after no difference on bad scoot.

*************************************
- Took the NEW carb from new working scoot and
replaced onto this bad scoot.
*************************************

- STILL NO DIFFERENCE!

See my other video with the "the good scooter".

Comments are welcomed!!!

Category:

Autos & Vehicles

Tags:

• scooter
• stalls
• stopping
• engine
• problem
• troubleshooting
• valves

[FairTaxTed]

Facebook Group, Search for:

Honda Reflex 250cc Scooter Clones

[FairTaxTed]

I added another video today. This one shows some of the upgrades I made including the bulbs, car stereo, cup holder, etc.

[bombidae]

I saw you thread btw, I stripped the bike down and the engine looks totally different...

[FairTaxTed]

Not sure what you mean. the only thing I show in the video is the cover removed from the clutch area.

[bombidae]

what about the lighting? My 250's lights flutter or winks when on low rpm. I pull the throttle back and it cuts off, sometimes in the middle of traffic.

[FairTaxTed]

Do the valves. Also suggest replacing the vacuum fuel punp with an electric one. I used a Mr. Gasket 42s. Pep Boys, Advanced Auto, Auto Zone, etc usually has one for about $30-40.

If this helps the cutting off in trafic issue, it may also resolve the lighting issue as the engine will be more stable, run smoother, etc.

[FairTaxTed]

RPM should be about 1500 or so when idling from what I have been reading. Lighting issue is prolly caused b/c of the low RPM.

If after you adjust the valves, replace the fuel pump, adjusted the idle and still have an issue, maybe voltage regulator is bad? If lighting is OK after all the above is done then great.

I picked up the LED brake and turn signals from Pep Boys, Advanced Auto and/or Auto Zone. The replacement headlamps from a local Scooter shop.

[shomecoatings]

So what lash did you finally set the valves at? Is there a manual available for this scoot? Johnny

[NobbysPcHelp]

GY6?

[LetsRide738]

if the valves hit the top of this piston as seen on this video, it is very bad!. damaging your piston will not help for engine!. lol

[lankysamboy94]

m8 my moped does the same thing. what have you got to set the valves to

[loopofhenle1]

Extremely Helpful! Exact problem thank for the help!

[apricotsnms516]

wow thanks so much i was having the exact same problem and this really helps! but one question my belt sits down in the clutch and doesn't come back up when i start going any ideas?

[ding0925]

Sounds like you need adjust the valves...lol

[Ganja4Dummies]

do not buy from county scooter, they are being investigated for fraud, check yourselves on Ripoffreportdotcom, search for county imports, and see for yourselves al the issues concerning this company, its really sad what they do to paying honest customers!

[bbishoppcm]

I had this EXACT same problem on the 1986 Honda Elite 150 I'm restoring. THANK YOU for this video! I would have NEVER guessed to check the valve lash adjustment to solve this problem!