NEW Scooter NOT running right.

[gmcjetpilot]

Quick intro first - new to forum, quick intro, riding motorcycles for +30 years. New to scooters. Every time I visit Asia, I rented a scooter and love it. Bought a BMS Prestige 150cc scooter. It ran at first. Idle too low so I adjusted the idle stop only. Then it would not idle, would bog, not Rev on center stand and die. I know what I did would not affect that. Maybe taking the seat off and putting it back on did something?

I fiddled with it (doing nothing but just some checking) and got it running (I thought).

* Pulled plug lean and gap good (NGK) and getting spark.
* Drained fuel to see if junk was in it. Good, clean, but did not change filter.
* Checked vacuum lines. The air-box duct to carb was loose but not bad.

It ran without stopping on one long 20 mile ride I (bravely) took. I say brave because it had died before and since that ride.

When I did go on the one long ride, it was OK but down on power, got to 50 mph briefly, 40 mph no problem. I had a few other successful short local rides in the neighborhood of a few miles.

However now I go a block and it dies, will not restart. Right now it will not even start after letting it sit. Guess fuel starvation for many reasons. Bike has about 28 miles on it now.

[rks]

I hate to say this again, but....did you perform a PDI on this scooter before running it? It is a very necessary procedure when purchasing a Chinese scooter.

You say it has spark....so it probably is fuel starvation. That sounds like fuel or vac lines...sometimes they come from the factory way longer than need be....did you get one pinched under the seat bucket when reinstalling it? Make sure fuel tank vent is working also, yours probably runs to a small plastic canister on the frame near the seat.

I would pull the valve cover, check the gaps. I hope you changed the oil your scooter came with.

50 mph with only 20 miles on the scooter.....not a good idea. But then again, it is your scooter. Good luck finding this bug and correcting it, and do a good PDI, or this will be just the first, of many more to come.

[Roscoe]

What I'd do..... Give it shot of starter or carb cleaner fluid into the carb throat ... if it starts and quits it's a not getting fuel problem. With the air cleaner off you can also try to hand choke it while cranking. With the fuel line disconnected crank it a bit and see if fuel runs out to, check the filter and petcock. When you are sure you are getting fuel to the carb then it's probably a problem with the carb..... probably. If this is new it should be under warranty?

[gmcjetpilot]

Originally Posted by rks

I hate to say this again, but....did you perform a PDI on this scooter before running it? It is a very necessary procedure when purchasing a Chinese scooter.

Well after I took it out of the crate, and put some items on, I did give it a once over. The manual says keep the break in oil for 150 miles. Why change it? I'll do that now, just asking. Is there something wrong with the factory delivered oil? I plan on going to mobile one at some point, but for now I will use basic oil.

You say it has spark....so it probably is fuel starvation. That sounds like fuel or vac lines...sometimes they come from the factory way longer than need be....did you get one pinched under the seat bucket when reinstalling it? Make sure fuel tank vent is working also, yours probably runs to a small plastic canister on the frame near the seat.

Yes I thought of the seat bucket pinching something. I'll check.

I would pull the valve cover, check the gaps. I hope you changed the oil your scooter came with.

I will do that but the symptoms are not valve, I think. Agree. However I will give it a check, can't hurt.

50 mph with only 20 miles on the scooter.....not a good idea. But then again, it is your scooter. Good luck finding this bug and correcting it, and do a good PDI, or this will be just the first, of many more to come.

Yep keeping it under 60km/h or about 40mph. I went to 50 mph for a brief period, just for fun... shame on me.

[gmcjetpilot]

Originally Posted by Roscoe

What I'd do..... Give it shot of starter or carb cleaner fluid into the carb throat ... if it starts and quits it's a not getting fuel problem. With the air cleaner off you can also try to hand choke it while cranking. With the fuel line disconnected crank it a bit and see if fuel runs out to, check the filter and petcock. When you are sure you are getting fuel to the carb then it's probably a problem with the carb..... probably. If this is new it should be under warranty?

Great trouble shooting tips... will do.

[gmcjetpilot]

Got a new AGM battery (from Walmart, free shipping $21.95). The new battery it came with was not holding a charge and discharged after one start attempt.

I drilled the gas cap with one small 3/32" hole at the root of the cap and handle.

This plus checking lines seems to have done it. It is running leeeeeeeean (lean). I ordered a 20 piece mid and main jet kit. I hope that will fix the light missing in mid and high speed acceleration. I filled with regular at first. I went with premium/super 93 octane. I noticed they called for 90+ octane and mid grade is only 89 octane.

I think I am going to SC the emission and vacuum valve. A manual petcock would be hidden, accessed by reaching under side bodywork, and going pure gravity would be more reliable and be ANTI-Thief. With it off if they try to ride off it would die.

[Smaug]

Originally Posted by gmcjetpilot

Well after I took it out of the crate, and put some items on, I did give it a once over. The manual says keep the break in oil for 150 miles. Why change it? I'll do that now, just asking. Is there something wrong with the factory delivered oil? I plan on going to mobile one at some point, but for now I will use basic oil.

The break-in oil will have all the sharp edges and dust/sludge that gets knocked off the inside of the engine. You've GOT to change that on Chinese stuff. Change or clean the oil filter too. It's not well-made enough to skip that. But that's not what's causing your lack of power.

Valve clearances would be the next thing I'd do, I think.

[gmcjetpilot]

Originally Posted by Smaug

The break-in oil will have all the sharp edges and dust/sludge that gets knocked off the inside of the engine. You've GOT to change that on Chinese stuff. Change or clean the oil filter too. It's not well-made enough to skip that. But that's not what's causing your lack of power.

Valve clearances would be the next thing I'd do, I think.

Thanks for the info. I'll go ahead and change the oil and adjust valves. I'm going to go with regular high quality oil, like 10-40W for the next hundred miles. Then I'm switching to synthetic, Mobil 1.

[gmcjetpilot]

I changed the oil at 45 miles. I have to say it looked good and was oil. Am not going synthetic or blend until I get 150 miles.

The valves were checked. The intake was spot on 0.004" and did not need to adjust. The data tag says 0.003 to 0.005 for intake.

The exhaust was too tight, under 0.005 even under 0.004, so I adjusted it. The data tag says 0.005 to 0.007. I went with 0.006, but think I will go back to 0.005"

It is running fine. I think the new battery and drilling the 3/32 hole in gas cap did the trick....

[rks]

Good job. Glad it's running better for you. The only way to better understand your scoot, is to jump in.... and get your hands greasy. Sounds like you're doing just that...congrats.

[gmcjetpilot]

Originally Posted by rks

Good job. Glad it's running better for you. The only way to better understand your scoot, is to jump in.... and get your hands greasy. Sounds like you're doing just that...congrats.

Yep finally took it for a nice 12 mile ride to run some errands after days of rain or being at working. It ran better for sure. I'm still running lean, by the plug and feel. Bought 20 piece jet kit being shipped on slow boat from China. I can say without "placebo effect", it is an improvement. Here is a pic of my new scooter after another errand run to the grocery store.... needed critical supplies. Who knew Corona came in 7oz bottles.

[rks]

Now, my scoot has hauled a gallon of milk home in that location, but come on gmcjetpilot, you need a trailer hitch and trailer, for loads like that......or something like my Ural