Bike dies when coasting

[SlendyMayne]

Hey everyone. So I've recently been running into a problem with my zongshen gs250. Whenever I'm riding and I pull into a stop, when I start coasting my bike dies. I can start it back up go continue riding but the same issue happens when I coast. Anyone know a possible reason behind it or a solution maybe?

[JerryHawk250]

Could be a couple of things. Idle mixture may need adjusting. Idle set to low.

[SlendyMayne]

Could be a couple of things. Idle mixture may need adjusting. Idle set to low.
Speaking of the fuel screw, even when I have the screw sitting, the engine still runs.

[Adjuster]

Idle is too low but also sounds like you have other carb issues. Likely an air leak into the system somewhere.



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[ben2go]

Partially clogged low-speed jet or tight valve lash. I have experienced this, as you describe it, from both.

[SlendyMayne]

Partially clogged low-speed jet or tight valve lash. I have experienced this, as you describe it, from both.
I figured this I cleaned out the carb and the pilot jet was slightly clogged. Got it running again but the same problem occurred. I may need to get a bigger jet.

[SlendyMayne]

Idle is too low but also sounds like you have other carb issues. Likely an air leak into the system somewhere.



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Around how many rpms should I set it to? I had it idling it at 2k rpms maybe go a little higher?

[JerryHawk250]

Around how many rpms should I set it to? I had it idling it at 2k rpms maybe go a little higher? about 1500-1600 rpms. May just need to adjust the idle mixture or check valve lash. Valves set to tight can cause this symptom.

[SlendyMayne]

about 1500-1600 rpms. May just need to adjust the idle mixture or check valve lash. Valves set to tight can cause this symptom.

Still new to the Moto world. Where's the valve lash?

[humanbeing]

...may need to get a bigger jet.
Those Teikei pilot jet is little bit tricky to buy locally but online shop had everything
http://img.alicdn.com/imgextra/i4/77787886/TB2kGzFqyC9MuFjSZFoXXbUzFXa_!!77787886.jpg
Still new to the Moto world. Where's the valve lash?
d/l TW200 manual http://www.lisaeaise.com/tw.pdf or youtube it

[ben2go]

1100 to 1200 is the actual idle speed. New riders may find it easier to start from a stop with the idle at 1500-1600.

[SlendyMayne]

Those Teikei pilot jet is little bit tricky to buy locally but online shop had everything
http://img.alicdn.com/imgextra/i4/77787886/TB2kGzFqyC9MuFjSZFoXXbUzFXa_!!77787886.jpg

d/l TW200 manual http://www.lisaeaise.com/tw.pdf or youtube it

Woah is this the bike that zongshen engine copied? It uses the same kind of carburetor.

[Megadan]

Still new to the Moto world. Where's the valve lash?

Valve lash is a term to describe the gap between the rocker arm and the valve. This gap exists to account for thermal expansion of the various metal parts of the valve train, and allow the valve the ability to fully seat and seal the combustion chamber. Otherwise, it causes a number of running and rideability issues. So there is no "lash" that can be pointed to. Lash is something you set.

Given that you have a SOHC engine, you should have two caps on the valve cover, one front and one rear with big hex heads on them. These caps come off to give you access to the lash adjusters.

In order to properly set valve lash on an engine there are a couple of criteria that must be met.
1. The engine should be stone cold - preferably sat overnight or many hours.
2. The engine must be set to Top Dead Center on the compression stroke. This means that both valves are in a "loose" condition that will allow you to make proper adjustments. If you are not at TDC on the compression stroke, then you are effectively wasting time.

[JerryHawk250]

I think Megadan and humanbeing got you covered on this one. :tup:

[SlendyMayne]

1. The engine should be stone cold - preferably sat overnight or many hours.
2. The engine must be set to Top Dead Center on the compression stroke. This means that both valves are in a "loose" condition that will allow you to make proper adjustments. If you are not at TDC on the compression stroke, then you are effectively wasting time.

Found a YT video to find the TDC. Now I have to wait several hours till I go home and work on my bike. >:( Thanks man! I'll keep you guys updated on the progress of my bike. I was losing hope for a little while until you guys came along. <3 Off topic but have you guys heard of the kymco k-pipe?

[culcune]

Watch the video; it is easier than it sounds. Can you post the link to the video here? I have heard of the K-Pipe, and from what I understand it is an okay bike, but in a 4 way comparison between a SSR Razkull 125 (Chinese Grom clone-ish bike), a Honda Grom, and a Kawasaki z125, it lost. Not because it is bad, but because the reviewers felt the others were better. However, one of our members just recently took ownership of the new Kymco Spade, a bike that kind of came out of left field following the Spade (seemingly no notice prior to launch--it just kind of arrived and stole the K-Pipe thunder).

http://www.chinariders.net/showthread.php?t=19951

[SlendyMayne]

Watch the video; it is easier than it sounds. Can you post the link to the video here? I have heard of the K-Pipe, and from what I understand it is an okay bike, but in a 4 way comparison between a SSR Razkull 125 (Chinese Grom clone-ish bike), a Honda Grom, and a Kawasaki z125, it lost. Not because it is bad, but because the reviewers felt the others were better. However, one of our members just recently took ownership of the new Kymco Spade, a bike that kind of came out of left field following the Spade (seemingly no notice prior to launch--it just kind of arrived and stole the K-Pipe thunder).

https://youtu.be/-HxWAwA-FZo
Here's the link to the video. And you're right, it's a lot easier than it sounds. I just have to buy a feel gauge at AutoZone after work. Shame that that k-pipe didn't do so well but I've heard of the Spade. A dealer by my house sells them along with the k-pipe. I'd love one of those myself.

[culcune]

Don't let me talk you out of the K-Pipe; the magazine is the online magazine--crap, forget the name, but they tested the 4 bikes in San Gabriel, or some small city in the San Gabriel Valley, and into the mountains, and then back down, so were doing some fun to cost scale of economics which is why the SSR Razkull won and K-Pipe lost. It wasn't the cheapest nor performed the best.

[SlendyMayne]

Don't let me talk you out of the K-Pipe; the magazine is the online magazine--crap, forget the name, but they tested the 4 bikes in San Gabriel, or some small city in the San Gabriel Valley, and into the mountains, and then back down, so were doing some fun to cost scale of economics which is why the SSR Razkull won and K-Pipe lost. It wasn't the cheapest nor performed the best.

Well thats why I was considering getting one. Since I live in one of the country's most congested cities, I want something small, cheap, and high mpgs to get around in. I do prefer the size of the k-pipe but the 1.2 gal tank does bother me. But I'll definitely consider the Spade or the Sym Wolf, mainly for the power. Ninjas and CBRs are way too common. I want to stand out ;)

[Megadan]

Well thats why I was considering getting one. Since I live in one of the country's most congested cities, I want something small, cheap, and high mpgs to get around in. I do prefer the size of the k-pipe but the 1.2 gal tank does bother me. But I'll definitely consider the Spade or the Sym Wolf, mainly for the power. Ninjas and CBRs are way too common. I want to stand out ;)

Another Grom-like option, but uses a 12hp counterbalanced 150cc vertical engine like the Kymco Spade, is the Lifan KP150 Mini. Being a Lifan, it should be of very decent quality, and they retail new for around $2200-2300 ( sometimes more depending on the dealer). The only thing I don't know about, is if they are 50 state legal.

If you want something with 17 inch wheels like the K-pipe, and a little bit bigger than a Grom sized bike, the Lifan KP-200 would be the next step up. This would be a bike similar to your GS250, but it is water cooled and has a 6spd transmission.

[SlendyMayne]

If you want something with 17 inch wheels like the K-pipe, and a little bit bigger than a Grom sized bike, the Lifan KP-200 would be the next step up. This would be a bike similar to your GS250, but it is water cooled and has a 6spd transmission.

What's the problem with water cooled engines?

[culcune]

What's the problem with water cooled engines?

He just means it won't be 'simple' like the air-cooled Chinese enduros many members have, or your air-cooled bike. I know I have seen the Lifan KP150 Mini advertised in the L.A. area Craigslist, as well as the Lifan KP200/KPR200, but when I last called Lifan a few weeks ago, the customer service rep did say that it was not CARB certified, while the two 200s and the S-Ray scooter are CARB certified. The KPR 200 (fairing) is similar in spirit to your bike (small-displacement sporty bike), but has fuel-injection and liquid-cooled engine as you were asking above.

If I move back to California, besides my TGB Express scooter, I am thinking of the Lifan KP200 (non-fairing) as cheap transpo.

[culcune]

Here is the video--it was motorcycle.com I don't think there is anything wrong with the K-Pipe, unless it is overpriced, all things being equal. Use the advantages of the others to make a good deal. :tup:

https://www.youtube.com/watch?v=H1G5lgbj74Q

[SlendyMayne]

Here is the video--it was motorcycle.com I don't think there is anything wrong with the K-Pipe, unless it is overpriced, all things being equal. Use the advantages of the others to make a good deal

Hmm it did give me good insight on the k-pipe. But after reminding me of the Spade, I might end up going that route. It's 1,000 bucks more but it'll perform much better

[culcune]

Did you read the thread from SamM regarding his Spade? He seems to like it a lot. That will give you first person experience of the Spade.

[SlendyMayne]

Yea I read through it, that's what's convincing me to go and check it out. I was considering the Sym wolf classic since it has a tad bit more power but the Spade has a hell of a lot more aftermarket support.

[SlendyMayne]

Quick update. Turns out the valves were definitely too tight. They didn't even move until I adjusted them. I used the PDF service manual that I was given. And I also discovered where my oil leaks were coming from the valve caps! So now I'm going to go ahead and buy new o rings for it.