Husq 435 won't start

[helmdog]

My Husq 435 got wet and would start after. It has

• new carb - fuel lines are good, primer bulb is working
• new coil
• new plug - gapped .5mm
• compression is good
• fresh gas
• removed the exhaust, not blocked and piston & cylinder look good viewed from the exhaust port

It is getting a good spark, as is seen by grounding the plug and using a tester. After pulling numerous times, I remove the plug and it is wet, so fuel is getting in. I've dried out the cylinder by leaving out the plug and rotating the engine. Also blew air through it with compressor. So it isn't flooded.

Putting everything back together it still won't fire. I've also tried several initial settings with the high and low adjusters. I even tried a shot of starting fluid. It just won't fire.

Am I missing something else?

 

[Bob Hedgecutter]

Timing- flywheel key shorn.

 

[helmdog]

Doesn't appear to have any damage. I'll pull the nut and check just to be sure.

 

[Bob Hedgecutter]

Compression would be the next guess- or rather lack thereof.

 

[helmdog]

Flywheel is fine, pulled it off, no damage to the key. Compression is good. I didn't do a compression test, but it pulls like it should. It passed the thumb test, from back in my dirtbike days, I was always told if you can't keep your thumb sealed against the spark plug hole, there's enough compression to run. However, I will dig out my compression tester tomorrow and verify.

It ran well a couple months ago.

 

[Bob Hedgecutter]

Righto- remove the muffler and lets see the piston through the exhaust port.

 

[helmdog]

Yep, looked fine.

 

[Bob Hedgecutter]

Oh well everything is fine then.
So unless you are flooding the saw with your start up procedure- pressure and vac testing for air leaks of the massive variety is your next step.

All you need is the correct air/fuel mix entering the combustion chamber- spark and timing of that spark to make simple 2 strokes run if they have compression above 120 psi- all of which you claim the saw has.

 

[helmdog]

Yeah, it doesn't seem to make sense.
Guess I'll pull the carb again, and the intake, I didn't pull the intake block before, and make sure there isn't a vacuum leak there somewhere.

BTW, is that a Land Rover Series in your profile pict? I've always wanted one. Hard to find, and expensive, here in the states.

 

[Bob Hedgecutter]

Yes- Series 3, 1976 109 inch, 2 1/4 ltr 4 cylinder petrol.

 

[helmdog]

Nice, I did actually have a '65 Series II, but it was a basket case. Had to sell it when I moved.

 

[Bob Hedgecutter]

Borrowed this off the 240 thread- but it may very well apply to your saw also.

When I was removing the muffler to inspect the piston I noticed how dirty the spark arrestor was. Checking it again before reassembly decided to take wire brush to the screen which was nearly solid with carbon. Thought I would give it a try before checking the shaft key and the darn thing popped on the first pull. Few pulls later it fired up,