The recorded sound is definately a little different than what I hear in person. The grinding or catching like sound is not as obvious on the video, but you can obviously hear that there is something intermittent. Anyone know why the bike sounds so irregular when turning over. The bike intermittently sounds like something is catching or a clutch is engaging. The chamber is complete void of fuel and latter in the video you can see the compression being measured. The ignition button is being held down.

Thanks!

Video link to photobucket below

http://s303.photobucket.com/albums/n...t=PA040796.mp4

 

the chinese quads i've had in the past turn over faster than what yours is turning over. i can make out starter hesitation and to me, it's acting like back pressure that is slowing the starter down momentarily. unsure, like you said from lack of details from the video, but that's my guess based on what i'm hearing on your video. still unsure, i have never had that particular problem. wished i was there in person to help you out. good luck.

 

Is the quad in Neutral? It sounds like it is cranking in gear.
Also, if you crank these starters too long they get hot and slow down and have a grinding noise on slower cranking. I would charge the battery, let the starter cool, and make sure that you are in Neutral or that the clutch is engaged. Otherwise, from the video I did not hear anything out of the ordinary. Looked like a good compression test.

BTW, are you having trouble with this quad or just doing some maintenance?

 

I am having trouble. Bike wouldn't start or run without being fully chocked at all times when I got it. It was still very rough when running. It is my first bike and I thought it would be a little project and just need the carb cleaned, new spark plug, etc. Took carb commpletely appart more than once and completely cleaned it, even got a new carb- but same problem remained. Checked valve width, loosened the exhaust valve a little. Was checking compression here. Haven't put bike completely back together yet to see if there is a difference since changing width on exhaust valve.

New battery and it was fully charged- I did attempt one video of about the same length just prior to this one.

Clutch is fully compressed in the video, but I did notice the drive chain moving just a little when i watched the video back. So maybe the clutch needs adjusted????

The abnormal noise I hear at home appears to be drowned out on the video by other noise, but you can tell there is a change in the process. The abnormal event will occur at amost any point in the starting process. It may start in the first second, 5th second, or 10th second and it generally happens more than once during each cranking session.

Thanks

 

The starter gear clutch that engages the gear could be worn and be vibrating making the noise. Just a guess.

Rough idle and poor throttle response is a cause from the pilot jet. The 250cc should use either a PZ30 or a mikuni style 30mm carb. Remove the carb and check those jets. Make sure they are not clogged.

If the jets are clear, make sure you are using a fresh tank of fuel and a new fuel filter. Then start the quad and adjust the carb. There is a screw in the front of the fuel bowl on the PZ30 and a idle screw(with a spring) on the right side. If you have the Mikuni carb they are on the left side.

I suspect that the carb is the problem. You need to check that there are also NO air leaks. You can do this with carb cleaner. Just spray it around the seals of the carb, then the intake, then the head. See if the idle speeds up when you do this. If so, you have a seal leak somewhere.

When you pulled the plug to do the compression test what did it look like?
Was it a lean plug or a rich plug?

 

When I replaced the plug and pulled it this last time, it was black (rich?).

It ran so poor that it just tried to die constantly.

I did go through the carb several times with complete tear down, then got a new one. I will check what model and since it has set again for a little while, will go back through it as it has had a chance to corrode again.

Just put on a new filter. Also put new gas in the last time I tried it. Currently gas tank is off and empty, will put new in when all placed back together.

I forgot to mention, I didn't find an obvious air leak. Tested for one before I looked into the valves as a possible issue. However, it was running very rough when I was testing for an air leak.

Hopefully when I get it back together, maybe it will run well enough to get a second look for an air leak.

Since compression appears adequate- ring, piston, valves should be okay? Spark appears appropriate now(replaced stator). Problem should be limited to air leak or fuel issue correct?

 

With no gas going to it try starting fluid sprayed into the air filter and see how that runs. Should run great until that spray is burnt up. Are you sure the measuring needle in the top of the carb is correctly set?

 

This might help with the carb...
Carbs

There is also a clip inside the slide that adjusts the needle hieght. You can carefully lower that needle 1 slot to lean out that carb which may make it run better. You can also change the jets to larger jets, (use Kiehen) and then make adjustments with the idle screw and metering screw.

I believe if the plug was black and the bike ran poor, then you have a carb issue with the adjustments of the air/fuel mixture and you will need to do some tinkering to get things right.

This may also help......

http://webcache.googleusercontent.co...&ct=clnk&gl=us

 

I should add that a carb that needs to be choked is running too lean. It needs more fuel to go with the extra air when the choke is opened. Even though you have a black plug that indicates a rich situation, because of misfires the plug can foul and actually be too lean and need more fuel. This confusion makes experimenting both ways with the air/fuel setting necessary. Lean it out and see if things get better. Then richen it up and see if things get better. Write down the number of turns you turn a screw for adjustments so you know what you did to what. Keep track of your adjustments.

Even if the quad runs better lean, take the time and richen it up and see how it runs that way too. You have to know what adjustments were better and which were worse.

*****Also, if the adjustments of the carb screws aren't really helping, then you need to adjust the needle on the slide attached to the throttle cable. After a slide adjustment, go through and make adjustments with the screws again and see how this affects things. Once you dial in your carb you will have a quick starting, good running, powerful 250 with great throttle response!

 

Finally, success! I obtained this bike a year ago, and worked on it off and on when I had time. Initially, I think it had a carb issue. Tried to clean it out mutliple times, and then purchased a new carb. At that point, I lost spark due to a stator issue that Lynn helped me with. Before going forward, took apart new carb to see where needle was set. Changed gas, changed fuel filter, and found that the new carb was leaking fuel everywhere. Attempted to look for debris around the seated pin and float. Never could figure out issue and the new material never worked properly (attempted to blow it out and clean it), but replaced float and pin with old carb materials and it worked beautifully. (assumed debris but never found it). Now changed brand new oil, I had just changed without even running the machine. Still had an issue with having to fully choke motor. No air leak found. Checked valves and loosened exhaust valve a little as it appeared overly tight. Measured compression. Absorbed more advice from everyone here. Went back through the new carb and found the main jet plugged- I guess this happened from the old gas in the line prior to being changed? Anyway, I finally was able to start my bike without starter fluid and was able to keep it running without being fully choked! Now I just have to do a little fine tuning.

I would like to thank everyone for the time they took to give me advice. This place rocks!