Jonway YY250T By burrhead (Read 1,656 times)

[burrhead]

Hey guys......been a while since I posted last but had an issue with my scooter that I would like some help with. My wife and I were on our way on the scooter to the New Orleans Saints game this past Friday evening. There is an expressway that we always use to go to the dome for the games and with my wife and I on the scoot I generally ride at about 50 to 55 mph. While riding the scoot for about 15 minutes all of a sudden it lost power and died......I had to coast to the side of the road. The gas gauge was reading about 1/4 full so I did have power at least power to the fuel gauge but when I unscrewed the gas cap I couldn't see any liquid so I just assumed I had run out of gas. After about a minute or two I tried to crank it and it started again. So we rode about another ten minutes till we got to a station and I filled the tank. Then we went to the game so the scoot sat idle parked for about 3 hours. So at this point I thought I had solved the problem by filling the tank and I would just need to address the fuel gauge issue. Well on the way home I had the same issue......riding along at 50mph the scoot completely died......no lights no nothing! So I coasted once again to the side of the road. A AAA service truck just happened to be right behind us when the scoot died and he stopped to ask if we needed some help.......after a couple of minutes talking to him I tried starting it again and it started and ran great all the way home with no more issues. Crazy! What do y'all think might have happened and any advice on the first thing to look at? Thanks, Dave(burrhead)

[alleyoop]

Sounds like you need to adjust the valves and the motor just lost to much compression to keep running.
They usually will start up again after a cool down but then the same thing will happen after the motor gets hot.
Alleyoop

[burrhead]

Thanks............that was my first thought too since it seems a lot of responses to other issues tie back to that......thanks.......

[burrhead]

I just looked at the video for setting the valves on a 257cc Linhai engine.........it was posted by JR on August 13, 2011.......does anyone know of a video on this that might be more current. JR mentioned in the video post that there might be an easier way. But I am still assuming I will need to remove all of the mid-body and rear plastics including the bottom pan. Jeez I just can't wait and yes patience is a virtue! LOL

[ellpee]

Yeah, it would sure be a boon to scooterkind if Ching Chong Industries would engineer some really, really easy access panels into their body plastics. Good luck solving your problem.

[burrhead]

Was wondering how often the valves need to be adjusted......is this something most of y'all do on a periodic basis like changing the oil or only when you start having issues? Is this something inherent on scooter engines because that not something we generally see on automotive engines......right?

[ellpee]

Used to be a periodic driveway mechanic thing with cars, but apparently technology has improved to the point where it's not needed nearly as often. As far as scooters, most of what I've seen here and on other forums and websites seems to suggest every 5k or so, or when problems arise. I'm at that point with my Roketa, will be getting it done in a couple months when we get back to Tucson. Fortunately I have the Honda clone, which is supposedly lots easier than the Linhai.

[burrhead]

My scoot only has 500 miles on it that's why I'm perplexed........but I will tackle it soon and let y'all know if that did the trick! Thanks for all the great advice.....it is much appreciated......

[alleyoop]

Aug 20, 2014 12:23:44 GMT -6 burrhead said:

Was wondering how often the valves need to be adjusted......is this something most of y'all do on a periodic basis like changing the oil or only when you start having issues? Is this something inherent on scooter engines because that not something we generally see on automotive engines......right?

When you come down to it, it all depends on the quality of the head and valves really. If the metal used was of good quality and it was forged properly the valve seats will not compress as much and the same with the valve head. I have a real good head on my Big Bore Kit and I do not have to adjust them for over 4000 miles. Most of your cheaper scooters you will find every 500 or so miles the valves will tighten up and about 1500 or so miles the adjustment times get longer now that the metal has compressed many times over.
Alleyoop

[burrhead]

That certainly makes sense......and yes this is a cheapie but fun as heck! Thanks.......

[bhinch]

I have a 2008 MC54B Roketa (257 cc)and have over 11,000 miles and have adjusted the valves only once. I set them on .004 intake and .006 exhaust. The reason for the early adjustment is that the valves where not set properly from the Chinese factory. The Intake is close, but the exhaust is too tight, no clearance, so the engine heats up and the exhaust valve will not close. The idle goes away and it will not start from lack of compression, to pull a vaccum on the fuel pump. The engine is just an air pump, no compression no vaccum.

[burrhead]

Was talking to someone at work about my scooter issue and he asked me what kind of gas I am using......I told him Shell premium.......he said that might be part of the problem also since Shell gas has ethanol. There is a station close by called Pure that has gas with no ethanol. Does anyone think this is an issue with these Chinese scoots as engines tend to run hotter with ethanol gas?

[gatekeeper]

If you have the choice use gas that doesn't have ethanol in it. Scooters run ok with it but ethanol attracts water which causes more problems during storage. It is also hard on some of the fuel hoses that come out of China.

I think Alley is correct. Sounds like you need to adjust the valves.

It could also be that your gas tank isn't vented well enough and at higher fuel demand you are getting a negative pressure buildup in your gas tank, stopping fuel flow. You can check that by loosening the gas cap and test driving under the same conditions to see if the scooter still dies.

[burrhead]

Started the valve adjustment procedure today.........removed all necessary plastics! Taking a break.......thanks for the reply!

[burrhead]

I'm confused......I have removed all the plastics and my engine doesn't look anything like the two videos posted for adjusting the valves......I took a picture of mine but don't know how to post pictures.......can anyone help please......