Help Please with Shindaiwa chainsaw

Hello, I have a 490 Shindaiwa chainsaw that was working and it acted as if it was running out fuel and died. Things I have checked, replaced the fuel, replaced spark plug, checked fuel filter, put fuel into the spark plug hole, check the spark plug for fire. I also did a compression check and I have 100 + PSI. The saw doesn't attempt to start its only has 1 to 2 hours of run time.

If anyone has any direction i would be grateful

 

Did the spark plug have fire and is it still under warranty?

 

Yes it has spark and no warranty

 

With 100 psi compression and fuel added through the spark hole, it will fire.

First dump all the fuel out of the tank. Then with full choke and no throttle spin the engine over about ten times to get all the fuel out of the carb. Then pull the spark plug and full throttle no choke spin another ten times. This will purge all the fuel from the crankcase and combustion chamber. Now put a tablespoon of fuel down the plug hole and a good plug with verified spark back in it.

Full throttle and no choke -it will try to fire.

 

Ok, I will try this in the morning. Thanks for the advise I will post and let you know if it works

 

Did as advised and it gave no indications of starting. Any other suggestions

 

You have to pull it over a few times to get it to fire. It won't start, but it should hit a couple of times in succession.

You do have a good spark, though? That would be a bright blue spark.

When it died when running, did it speed up right before it died or did it just "bla out" and quit?

 

It did not hit at all, no bright blue spark but a yellowish white spark,it bla out and quit

 

did ure saw sputter at all when u added the gas, what are you using to see the spark???? ho wold is this saw, When I sold shindy a few yrs back they did not have a 490, a 488 yes, They have used soild state modules for years and they very rarely let go. (( percent of the things I work on is gas related , I would look that way , what type of plug ngk or champ

 

No the saw did not sputter, I'm visually looking to see spark and the saw I purchased a little over two years ago but it only has 2 hours of run time on it. Plug type NGK the original plug, I put a new plug in but it did not help - I put the new plug in my poulan and it started.

Its a 490 Perfessonal

 

Normally when they die when running, if lack of gas related you would have some type of symptom prior to it dieing. Like a speed up if the fuel supply was being cut off. It would have the same effect as a fuel/air mixture that was too lean, which in effect, it is. then it would run at idle, but die at any throttle opening above idle.

Once you have a good spark and compression and you have removed the carburetor feeding of fuel from the equation, you will get a hit from the engine. That's what you have done with emptying the fuel and hand feeding it. You may in a rare occasion have a flywheel strip a key from the crank which affects the timing and results in a no start, but that is very rare on a chainsaw, unless the crank nut was loose and the flywheel worked to the outside. That seldom happens, though.

When you have a saw flooded they can be a bear to get started. But since you have only put in a limited amount of fuel to the combustion chamber with the spoon and you spin it over enough with no choke and full throttle they will hit if you have compression and a good spark. Why it died in the first place would likely go to the carb or the fuel feed to the carb.

I just saw your post about the yellow spark. That would be a weak spark that wouldn't fire in a compressed air environment. That would be the problem.

Either the spark plug or the ignition module is going bad. Disconnect the grounding wire from the kill switch and try it again. If the yellow spark persists the module is likely the problem.

 

That makes more sense because of the symptoms it shown when it quit running. As I said before this saw only has 2 hours of run time. The 490 has a metal clip that grounds to the casing it does not have a two wire system. It does not have a standard toggle or rocker switch. How difficult is it to change this module. Is there any test with a digital ohmmeter that will verify it.

 

All modules typically have the one wire. It's a ground that goes through the toggle switch to ground. The switch is thrown to run and breaks the circuit to ground. Throw it to off and the circuit is completed to ground and kills the engine.

It's not difficult to change. AS far as testing, just about everyone that does shop work here would love to have a device to test those things conclusively. What happens is a cold module will read differently than one that is running and messing up at the time. It's just hard to test them. A lot of manuals will actually say to replace them with a known good one to test it.

As far as changing it, the price is the hardest to take. You just remove the recoil rope starter. There is the flywheel with the module facing it. Take out the two bolts holding the module on, make sure the new one is oriented the same way, and put in the mounting bolts slightly snug with the module up off the flywheel and the flywheel magnets turned away from the module. Then put a business card between the module and the flywheel, turn the magnets under the module, letting the module come down tight against the card over the magnets/flywheel. Tighten the module mounting bolts, pull out the card and reassemble.

 

Thank You so much for all your help, I will track down the parts and give it try.