Craftsman BackPack Leaf Blower No Spark

[welchs101]

if we assume it is low.........and we assume that the valves need adjusting.......what on earth would i adjust them too?

 

[StarTech]

The numbers from that tester are meaningless
It is not suitable for small engines and to get a proper reading you will need to pull the starter around 100 times and even then it would be suspect.
For small engines ( 100cc or less ) you must use a tester with a solid connector or a very short connector with a valve at both ends .
Then you need the right adapter to screw into the head that has the exact same volume displacement as the spark plug.
OTOH it can be used for monitoring wear over time by noting how much the readings drop as a percentage of the new reading but absolute numbers are meaningless .

Now FWIW 65 psi, if that is real is right on the border line for 4 strokes and way too low for two strokes

I have to disagree with part of this. I use an Actron version with a very similar hose setup. The problem arises if the check valve is at the gauge end and not at the end of the hose. The Actron I use has the check valve (schrader valve) at the end of the hose right at the cylinder. With valve at the gauge the hose has to be fill on every stroke before the valve even attempts to open where as if at the cylinder end then valve opens right away and close holding the charge in the hose.

 

[Hammermechanicman]

One is designed for small engines the other is for automotive but has the schrader valve at the end of the hose. Both readings from the same chainsaw

 

[welchs101]

in looking at the Craftsman backpack blower (Model number 316.794790) ....does this thing even have valves? If so i cant find them..........

 

[welchs101]

so i was just reading........this 2 cycle engine may not have valves

so i guess i am back to the drawing board on this one.......i am not sure what to do to figure out why this thing wont start.

i checked spark using one of those spark checkers and the light comes on.....so i am assuming i have spark.
as i said earlier i rebuilt carb using parts from a carb kit...........thoughts on what do try?

fyi: as i said before i am just trying to learn a little here........i really dont care if if this back pack ever really runs again but i am just trying to learn a little.

 

[bertsmobile1]

Well where to start .
SOP for non starters is to try some carb cleaner
That does not work the try a hot ( as in heated with a hot air gun ) plug to make sure the fuel is vapourised because only gases can burn.
Still no bang then it is off with the flywheel to check that the timing key ( usually cast into the flywheel ) is intact
Now I do this every day of the week so I can feel one that is too low on compression but in your case it would be off with the muffler and check the bore with a strong torch for scoring and that the piston ring is free and that the exhaust port is not clogged with carbon

If you have a compressor then you can slide the carb off , turn it sideways and with the fuel lines still connected turn it sideways and blow air through the carb to see if a strong stream of fuel droplets coms out of the carb.

After that there is not much you can do without proper tools
The crankcase seals really need to be pressure & vacuum tested but a very rough test is to pour some heavy oil down the induction port the pull the start rope slowly to distribute the oil over the seals a dozen or so times then pull it quick to expel the oil , replace the hot spark plug & see if it will go bang ..