20 Most Recent 2012 Yamaha YZ 125 - Page 5 Questions & Answers

needs new spark plug, or bad electrics.

if you have no compression could be a number of things , bad rings , bad valves broken rod , it will lockup if you try to start it my guess it to rebuild it before you throw a rod and then you have junk

clean the carb out !

From what I found it looks like it is a 96'

you takin the mik as there is one feed pipe

seized piston, cracked internals no good whatever it is

Check your oil for metal particles. Is your oil level correct? You may have ground the innards to death.

Yes Tim. A lot of Yamahas' are restricted somewhere. They generally place restrictors in one or two of several possable places so I'll list them.
In the airbox-in the air intake as well as behind the air filter.(not common)

In the inlet manifold-in front of the carby-more common.

In the exhaust at the header(where the exhaust bolts to the cylinder head)-in the form of a washer restricting the flow.-very common

In the muffler- in the outlet-sometimes internal.

If your bikes exhaust note is extremely quiet then I'd start at the muffler!!

Also note that you'll need to check your jetting afterwards but don't be alarmed- if it runs better all & good
If it causes a miss or hesitation go up a size in the main jet is all that is usually required

Hope this helps
Regards Andrew

Just a thought, check to see if there is any obstruction in the airbox or air filter, and that the air filter is installed properly.

You don't " get a cylinder cleaned ". Who ever says that doesn't know what he is talking about. I assume the engine is a two stroke. The gas/oil mixture should be 32 to1. That means 4 ounces of two stroke engine oil to one gallon of gas. If the scooter has an automatic oil pump be sure there is oil in the oil tank. It should automaticly pump the engine oil at the proper rate. If this is an older scooter, you could remove the cylinder head and de-carbon it and then check the exhaust port to be sure the port has not been made smaller due to carbon build up. The port should be about 1/2" tall and 1" wide. Also check and clean the air filter. If it is a new scooter is it still under warranty?

were can i fineceder the fuel fillter on 2005 isuzu as

your valve timing is incorrect

You don't decode it. It is only a production run series number. Mororcycles are like cars in that respect. It is the frame number, AKA the "VIN number", is what carries all the information. Call a dealer with the frame number and he can tell you year, paint color, specific model and more. They may have a problem if the bike is too old. Yamaha changed to a newer code system a few years back.
Can I get a “very helpful” rating on this answer?

which part do mean that you cant reassemble? be specific... even the woodruff key is easy to put back.