Venox 250 Stalling issues

[jken1988]

Bought a new 2009 Venox last year, and broke it in only going about 35 mph for the first 1000 miles like the manual said to.

After that, it stalled on a really hot day when I was riding above 40 mph. I couldn't get it started for about 20 minutes. After that, I tried to ride it home, but it stalled again, after hitting 45 or so. When I got it started again after that (I had to wait again) I took backroads home and drove it slowly so it wouldn't stall.

Took it into the shop, since it is still under warranty. They couldn't recreate the issue, but replaced the rollover valve anyway, just in case.  I rode it for the rest of the season, which wasn't really that long by the time it got back to me.

This year, I've had some other stalling issues, I can't remember exact circumstances for all of them, but I think I was going over 40 (at least 35) mph every time. I seem to remember it stalling after I rode through a cold patch one day (it was in the morning). I would have taken it into the shop, but I was a fair distance away from it at the time. Also, it was in the shop for such a long time before that I was just trying to get some riding in.  I used it on cooler days, since I thought temp might have something to do with the stalling. Finally, one day (it was a hotter sort of day), after hitting 45 or so, it stalled. I couldn't get it to start. Took it into the shop, they replaced the regulator. Again, it took a while to get back to me.

Second or third ride after the shop, it stalled out while I was on the freeway going 65-70. I got it to start again after 30 seconds or so. It was fairly hot that day. It stalled one other time, I was going at least 40 mph then.

When it stalls, it seems like the engine loses power and dies out slowly, which could indicate a fuel problem, but since the regulator got trashed, I don't really want to rule out electrical.

Its still under warranty, but seeing how long it takes anything to get fixed at the shop, I'd like to try and troubleshoot it myself before I take it in. I don't want a repeat of last year where I never get to ride. Nor do I want my warranty to expire and never have the issue really fixed.

Also, I should note, the idle seems to fluctuate a fair bit. When I first got it, I had a friend look at it, and he thought that it was just "cold-blooded," and that the engine idled faster when it was hotter. He only looked at it really briefly, and personally, I'm not convinced anymore that the idling is temperature based. When I start it, it idles at one speed, and when I give it a little gas (in neutral) when the engine returns to idling, it seems to be idling at a different speed.

This might be normal, I don't know, I'm a novice with engines.

All that said, any fairly easy tests I could try to troubleshoot a little?

Thanks in advance.

[SydScoot]

I had a similar problem on my Kymco scooter. Would stall out, and not restart for a few minutes. Never seemed to be a consistent set of factors. Turned out to be the CDI. got a new one and hasn't happened since. I understand Kymco had some problems with faulty CDI's.
 Not a 100% sure it would apply to your model, but might be a possibility?

[cors50agility]

All that said, any fairly easy tests I could try to troubleshoot a little?

Thanks in advance.

Check your spark plug for unusual burn patterns ,exspecially those of a overheating engine.
http://www.google.com.au/url?sa=i&source=images&cd=&cad=rja&docid=DGGwBS5uUPfD_M&tbnid=gTNHqHWopVgXaM:&ved=&url=http%3A%2F%2Fmidnighttouge.blogspot.com%2F2013%2F01%2Fspark-guide.html&ei=EqcQUv-vCIeJ4ATptYHQBA&psig=AFQjCNH_lD91seZwbT5F7czmFIaMsP_2YA&ust=1376909458186260
Practice how to take out the  carburetor drain plug of the bike within minutes, do it while the bike is running normally and gauge the amount of fuel you drop.
If the plug is normalish, ride it somewhat normal to hard.
When the problem happens dump the fuel bowl to gauge how much fuel you had.
If you have the same amount as normal then its not fuel delivery.

If you can remove fuel delivery as a problem your one step closer to finding the cause.

[jken1988]

That sounds like a really good idea, I'll give it a shot and see how it goes.

[max oradea]

yes buddy check the spark plug burn pattern, there is another test you can do is to check if you have a vacuum lock on the fuel tank causing fuel starvation. and also check or just replace your air filter. its been in the bike for 4 years already, after two years paper filters become unreliable no matter the amount of times the bike has been in use.
Good luck!
Oh by the way to check for fuel tank vacuum lock problem is when you stall again someday pull to the side of the road, open the fuel tank then see if the bike fires right up after doing so, if it is a vacuum lock your plugs might look lean as well, but not always because it can variate on the carb setting.