Ok first question, when do you know you need a new chain? How do you know its worn out? Im not sayin i need a new one id just to know what to look for, i herd they last around 5,000 mi? i do have the 13t front sprocket on...

second question, i think im runnin a little lean, if you go towards the top of the needle does that make it richer? Mine is currently on the 3rd from top, if i move it to the second from top will that make it richer?

 

i dont remember the exact operation ems, but as to the chain wear, take a look in your owners manual, i remember seeing a diagram in their how to check it.

 

To check chain stretch / wear, the service manual says to hang a 10 kg weigth (about 20 lbs or so) from the lower portion of the chain and then measure the tight top portion between the C/S sprocket and the rear sprocket. Measure the distance the length of 20 links from the pin center of the 1st pin to the pin center of the 21st pin. The normal distance should be between 317.5 mm to 318.2 mm. The service limit is 323 mm - if the measurement exceeds that, replace the chain.

 

Going from 3rd to 2nd slot will make it leaner. The needle is further down in the hole which makes it leaner. Remember this; to RICHEN the mixture RAISE the needle.

Hope this helps.

 

ok so the chain just streches?

would it be better to put a bigger jet in or drop to the 4th slot? im runnin a 125 main...

 

There's chain slack inspection and adjustment which you take up by rotating the snails. After a while, the chain does stretch and eventually needs to be replaced. Also sprocket wear - when they begin to look like shark fins, it's time to replace the sprockets too. I always kind've figured all these parts wear together so when it is time to replace one, I wonder if we should replace both sprockets and the chain all at the same time?

 

Running rich or lean is not a simple "one or the other" situation, because there are different operating ranges (or engine speeds). You can be both rich at low speeds AND lean at high speeds (or visa versa).

I'm by no means an expert but I'll pass along I know.

The carburetor has different mechanism for controlling the fuel/air ratio through different operating speed ranges:
- Low Speed Jet
- Fuel/Air screw
- Main Jet Needle
- Main Jet

Unfortunately, there's an engine speed overlap between these mechanisms, so its not a simple thing to say "It hesitates when accellerating between 6K-9K so raise the needle".

I'll try to hunt down a diagram I saw recently that shows the engine speed ranges, overlaps, and interactions ... it will explain it a lot better than I can.

Back to your question about a bigger jet vs raising the needle: The main jet is the primary mechanism when you're running WOT (wide open throttle) ... the needle doesn't have a lot of effect. You choose the right main jet based on this.

The needle affects your mid-range engine speeds by essentially adjusting the main jet opening by either opening it or plugging it as the throttle slide moves up or down. The two factors here are which slot the needle clip is in (which is easy to adjust), and the taper of the needle itself (the only way to change this is to replace the needle with one that has a different profile).

Here are a couple links on CV Carb Tuning:
http://www.factorypro.com/tech/carbtun.html
http://www.factorypro.com/tech_tunin...m_engines.html

I know this isn't an answer to your question, but hopefully it will help you get to that answer.

Mike

 

ok,, that helps, but how do i know when its runnin lean and when its runnin rich?

 

It tends to surge when running a bit lean. When it's fat, it runs kind of flat.

But when it is just right! [sm=bounceybounce.gif]

 

You can also do a plug check run the bike at wide open throttle for a bit and pull the clutch in and hit the engine kill at the same time do not try to turn the key..... Pull the plug and check its color you can find pics online of ehat it should look like. This all depends on what area the bike is not running wright its not easy to get them perfect I have mine as close I I think it can get its running so good now. I'm setting up another one this weekend same as mine I want to see if I get the same results from another bike.

As for the chain look at the sprockets closely if you nothice any turning of the teeth or if your chain has a lot of sideways play or kinked links its done and you should always change the chain and sprockets at the same time most people don't but your just wasteing the new chain as it will not match the sprockets even if the was low miles on them.
Keep it clean and lubed it should last more than 5000 miles seeing how this bike does not have the power to test it unless you see and do brun out and hole shots all day