Roketa 250 Stalling By mikecop (Read 2,356 times)

[mikecop]

We had another nice February day here in Michigan--about 50 degrees. I took the Silver Wing on a ride for about an hour, which was great. Those 600 cc's really do a job. When I give it some throttle coming onto the freeway ramp I get up to 75 mph within a couple of seconds.

When I got home I took the 250 Roketa out for a short time. It often stalls when I stop for stop signs or lights. It seems that unless I back off the throttle very gradually it stalls. If you go from half throttle to no throttle it definitely stalls. It almost seems like it floods out. Usually I need to wait 10 or 15 seconds before restarting or it will not fire up.

When I first start it, I must start with no throttle and keep it at no throttle until it warms up. When it is warm, if I make certain that I decelerate slowly I can usually keep it running at the stop light As I stated above, if the deceleration is quick it will stall out. Any ideas about why it is so sensitive to the throttle action?

I plan to sell the Roketa when the nice weather hits this Spring, but I would like to get it running better before I put it up for sale.

[bhinch]

Hi....not knowing about your scoot.....I would say that the valves need to be adjusted.... .004 intake and .005 exhaust....then you can adjust the idle to 1800 to 2000.....enjoy the ride...

[bhinch]

I used .006 on the exhaust on my scoot..... just got home on the scoot.... nice weather...enjoy the ride...

[speedracer]

I agree the valves are off more then likely the exhaust.

[richardthescooter2]

I know those valves can close on you, the last valve adjustment I did the exaust was down under .003

[speedracer]

For some reason the exhaust valve is the problem. I have adjusted mine twice so far and both time the intake was fine, but the exhaust had closed a few thousands. Mine has gone 5,000 miles since the last adjustment and still runs great and doesn't stall.

[Alleyoop]

Yes the exhaust is the one that gets all the heat, the intake gets a chance to cool off from the incoming air and fuel. So the exhaust seats more into the head and will cause hard starting and wanting to die when coming to stops or your rpms are low. Reason is since the valve is not completely closing it is looseing compression.

Once this goes on for some time it gets longer and longer between needing a valve adjustment. It is mostly due to the metal used to create the head.

Thats like heating up a piece of metal and heating with a hammer to shape it or make it thinner. The valve gets really hot and when the fuel ignites BAM like hitting with a hammer it pushs into the head more usually until the head has no more give in the seat.
Alleyoop

[mikecop]

Thanks for the responses guys. I have looked at some previous posts regarding valve adjustment, so I will look up the "how to" regarding valve adjustment and try to improve the Roketa performance.

[scooter12]

Yep, it is your valves.