MS180 will not start etc

[twofar]

I recently bought a 'barn find' MS180 the would not start... still won't start after I did the following:

1. new carb - China
2, new fuel line (OEM) and vacuum ports on fuel tank and oil tank
3. new OEM ignition module and set to .2mm gap using feeler gauge
4. New engine (piston, shafts and body - as one unit ) - China
5. New spark plug - gap set to .5 mm per spec - Voltage checked at plug is good but cant see spark visually

I also added new gas. easy to pull w/o plug in but difficult to pull when plug is in

So, I still can't get to turn over...any help would be appreciated..I must be missing something

Thanks in advance
Roy

 

[Bob Hedgecutter]

Sounds interesting- basically replaced the entire saw with cheap parts and it still don't go- guess you have to check what is left.
Kill switch wire earthing out somewhere?
Its pretty simple, air and fuel mix in the combustion chamber- compression- spark and timing of that spark.

What "new" spark plug did you use? What name, makers mark or numbers does it have on it?

 

[twofar]

I recently bought a 'barn find' MS180 the would not start... still won't start after I did the following:

1. new carb - China
2, new fuel line (OEM) and vacuum ports on fuel tank and oil tank
3. new OEM ignition module and set to .2mm gap using feeler gauge
4. New engine (piston, shafts and body - as one unit ) - China
5. New spark plug - gap set to .5 mm per spec - Voltage checked at plug is good but cant see spark visually

I also added new gas. easy to pull w/o plug in but difficult to pull when plug is in

So, I still can't get to turn over...any help would be appreciated..I must be missing something

Thanks in advance
Roy

Thanks for your input, Bob.
The plugs that I have tried -all gapped to .5- are
NGK BPMR7A
NGK BPM 7A
Meiya L7T

I have checked the kill switch - both earth and power - I have power to the plug boot but i dont visually see the spark.

Thanks
Roy

 

[Bob Hedgecutter]

How are you earthing the plug to see visual spark?- Hard to rig up on a plastic saw without an added earth wire to a good earth point on the cylinder.
Throw any plug with L7T in the bin- they are as a rule rubbish.

Best to use an inline spark tester on plastic saws- more guaranteed earth with the plug fitted to cylinder and better indication of visual spark.

 

[twofar]

I must have been doing this wrong. I just used the spark plug boot. How should it be grounded - a ground to one of the points on the end of the plug? I just ordered an inline test.. should be here in a day or two.

I'll trash the L7T plugs..

 

[Bob Hedgecutter]

The threaded section/crush washer area must be grounded to the cylinder or something attached to the cylinder- as if it was screwed in place and contacting the cylinder when the saw is complete.
Easier done with the top engine cover removed- if you can, wrap a bare wire between plug hex and crush washer and fix the other end around a hole in the cylinder fin, or stud that holds the top cover.
The central electrode that is contained in porcelain carries the live current, the rest of the metal of the plug is to find earth- the strap on the bottom of the plug is earth and the spark is the pulse of live jumping to earth.

 

[twofar]

I mare jumper from the body of the plug to the cylinder. Good news is that I could see the spark. So now I have compression, ignition and spark - the only thing left that could be the cause is fuel. Next to take the muffler off and see if fuel is being injected when I pull the chord

 

[Bob Hedgecutter]

If you have been pulling like a schoolboy trying to start it and the saw is getting fuel to the combustion chamber- it should near be running raw fuel out the muffler and flooding to hell and back.
Pulling the muffler is an odd way to tell if fuel is getting in- starting with a dry plug- few attempts to start- remove plug, tip wet- its getting fiel, top dry- it isnt.

Other thing in the equation is timing- if the key is shorn on the flywheel and the flywheel has moved on the crank- the spark is not happening at the correct timing and the saw will never run.
You have replaced the engine with a complete Asian copycat version- so the flywheel has been off and stuffed up timing is a very real possibility.

 

[twofar]

Thanks. will be looking at that. When i put the flywheel back on the key was intack (for the most part) so I did slip in the grove on the flywheel.

took a look at the plug after repeated bulls on the chord... no luck- as dry as can be.
As i said previously the gas inlet tube is new oem as is the vent tube. perhaps the next step is the put an oem carb .
whe i put the new cylinde in I also put a new boot in. if it damaged the boot on thte lip do you tink that would make any differnce? I would think if the boot was damaged we would see the fuel go dirpectly into the cylinder instad of going through the little tube in the boot.

Thought?

thanks for all your inputs

Roy