No fuel 353 Husky

[RiverLogger]

Heeeeeelp!!! I have a husky 353 that I'm working on that won't pump fuel.

Here's what I know:

New fuel and impulse line, new fuel filter, complete carb rebuild.
No purge bulb model.
Carb is a Zama EL18.
353 has good compression.

Put the carb on my 346XP last night and the saw fired right up. When this carb is on the 353 it wont even pop. Also switched all intake parts from a runner thinking there might be an air leak there with no luck.

What am I missing?

 

[sunfish]

Checked the spark screen in muffler?

Or bad air leak?

Or no spark?

 

[nmurph]

....Or no spark?

My guess.

 

[RiverLogger]

Okay. Sorry, I also know it pops when I dump a little fuel in the carb.

 

[RiverLogger]

No screen in the muffler but I'll check the exhaust side over good to make sure there is no major blockage. Intake boots are good as well as a good seal on the cylinder gasket. Replaced compression release with a known good one also. Where else could it leak?

 

[lasmacgod]

Extreme longshot, but is it possible that the impulse port in the cylinder itself is blocked?

 

[RiverLogger]

I blew air through the whole impulse tract both ways.

 

[nmurph]

Are you sure the nipple is lined up with the hole on the flange? Those nipples are easy to get twisted to the side and develope a tear.

 

[RiverLogger]

Pretty sure but I'll recheck it. I tried two different flanges so I hope I didn't screw it up twice. Thanks!!!!

 

[nmurph]

What is the compression reading?

 

[RiverLogger]

145 on my crappy gauge. BTW what brand are the gauges from Baileys?

 

[nmurph]

It should run just fine with 145psi.

Is it possible the FW has shifted some? The fact that setup will run on one saw and not on the other is puzzling and limits the possibilities.

 

[RiverLogger]

Well I'll check that too but I can see no fuel moving up to the carb when I pull the cord. Fuel line is dry. Puzzling is an understatement.

FWIW I've tried three different carbs on this thing and none have worked. It has to be the impulse system somewhere but I have had this thing down to the crankcase three times and cannot figure it out. The last time I put it back together I put myself in dipstick mode and double checked everything as I put it together reading the service manual to boot.

 

[nmurph]

A very severe air leak can prevent the saw from developing the necessary vacuum in the carb to pull fuel from the tank.
When you dribbled fuel into the carb, how did it sound? Did it sound like a normal start or did it rev to a scream (air leak sound)? Have you tried sustaining the saw running by continuing to dribble fuel in?

 

[RiverLogger]

I'll try to do a pressure/vac test tonight. Saw just burbled and died. I was happy with just knowing it wasn't a spark issue. I didn't try to run it for any significant amount of time. How do you do that and get the right amount of fuel flowing to the carb? You got three arms?

This saw ran a year ago and has been in the garage since. It was brought to me because my buddy couldn't get it started. I suppose the seals dried up enough over that time to cause such a severe air leak. Pressure/vac test will tell me I guess.

 

[sunfish]

I'll try to do a pressure/vac test tonight. Saw just burbled and died. I was happy with just knowing it wasn't a spark issue. I didn't try to run it for any significant amount of time. How do you do that and get the right amount of fuel flowing to the carb? You got three arms?

This saw ran a year ago and has been in the garage since. It was brought to me because my buddy couldn't get it started. I suppose the seals dried up enough over that time to cause such a severe air leak. Pressure/vac test will tell me I guess.

I've had em sit a year or more and not hurt the seals. But it does sound like a massive air leak.

 

[timberjak]

U removed the primer bulb it sounded like. Do you have the fuel lines correct and the line from carb to fuel bulb blocked somehow to allow vacuum to build?


Sent from my iPhone using my nose

 

[traktorz]

Fuel pump diaphragms incorrectly assembled? Stuck tank ventilation?

 

[nmurph]

U removed the primer bulb it sounded like. Do you have the fuel lines correct and the line from carb to fuel bulb blocked somehow to allow vacuum to build?


Sent from my iPhone using my nose

He deleted the purge bulb, and since he installed it correctly and got it to run on another saw, I assume he put it on this one the right way.

Fuel pump diaphragms incorrectly assembled? Stuck tank ventilation?

The carb worked on a 346.

It's not a tank vacuum problem. He would have lost the vacuum when he swapped carbs and since it hasn't run since, there's no way a vacuum could form.


I'm still not convinced it's not an electrical problem.

RL, why don't you swap coils from the 346 to eliminate another variable?

 

[RiverLogger]

Saw never actually had a purge so thats completely out of the question. I will try the flywheel and coil first and if that gets me nothing I'll pressure/vac test it.

Thanks so far guys!!!!