2002 suzuki jr80 dirtbike was riding about 1hr turned off came back tried to start would not start and still wont run i check sparkplug is getting fire line from gas tank to carb not clogged also has

SOURCE: 2002 crf450, rough running, back firing, hard start

Classic valve train issues. Sounds like the valves are tight. One thing that concerns me is the "sudden onset". Valves usually tighten over time.
Make sure you also tighten the cam chain as well.

SOURCE: my poulin chain saw wont run

Can you get it to run at all? if not pull it a few times and check if the plug is wet. Let me know

SOURCE: i have a 89 suzuki gsxr 750,it fires but will not

Clean the air filter and, if you have one, remove the water trap bowl on the fuel petcock and clean it. How good is the battery? Install new STOCK plugs. Bear in mind it may be time for carb kits. Other than your cleaning the carbs, the carb kits and balancing and synchronizing of the carbs are best left for the shop to do.

Check the exhaust pipes. If there is a restriction in the burned gases exiting the tailpipe then the bike will not run right, will loose power and even die if too much back pressure builds up. Disconnect the exhaust system and tick off the neighbors with a quick ride around the block without a muffler. If the engine still dies then exhaust is not likely to be the problem.

Check the compression on all cylinders. Depending on the compression, the bike may be ready for a valve job. If you pull the head for the valve job then you might as well consider re-boring the cylinders and install new pistons and rings. Bear in mind, doing a valve job and / or pistons is not recommended for the novice. The good part is that when the work is finished you will effectively have a new engine.

Please rate this solution as "FixYa" if I have answered your questions. Thanks!

SOURCE: dead pw 50 and sad boy.

Many things could cause the problem. Let me see if I can help out.
You have spark, but is it enough spark? A weak battery can rob power from the coil so only a weak spark is present. Get a new stock NGK spark plug to eliminate the possibility of a problem plug.

It is good that you cleaned the carb because that would be my second target. Reset the air and idle screws. IMPORTANT > do not tighten these two screws down. Only screw these in until they LIGHTLY seat. Now turn each screw one and one half turns outward. Clean or replace the air filter and be sure the bolts are tight on the carb manifold. INSTALL AN IN-LINE FUEL FILTER. Let the float bowl fill then start the engine. Set the idle speed with the idle screw.

Remove the cylinder head. run the piston down to the bottom of the cylinder. look inside the cylinder. On th carb side (intake) you will see an intake port > a large hole that lets gas into the cylinder. Now look at the exhaust port. It is possible the exhaust port is pretty plugged up with carbon. The intake and exhaust ports should be approximately the same size. Are they? If not then remove the muffler and take a screw driver and plastic hammer and knock the carbon into the cylinder, thus enlarging the exhaust port to its' proper size and allowing the exhaust gases to escape. Vacuum the carbon out of the cylinder. De-carbon the piston top and the cylinder head.

Get back to me and tell me what you find. If more is needed we will go further.

mike

• 112 Answers
• Posted on Jun 28, 2009

SOURCE: was running fine till whent on long ride, now it

posibly a problem with the stator