My Hotrod 170 project needs your help!

Ok, so based on Brads Eeeeeeeeviiiiil influence from this thread.

http://www.arboristsite.com/showthread.php?t=78747&highlight=170+muffler+mod

I decided to Beef up my 170.

Got the carb off Fleabay, disassembled it, and cleaned the main body of it in a jar of mineral spirits in my Harbor Freight US cleaner. Reassembled, and installed it on the saw.

Now here's where my problem begins. I dribbled a little mix down the carb throat cuz I knew the carb was dry. It fired, but of course quickly ran out. So after about 20 times of dribbling gas down the carb it REFUSES to pick up fuel!!!

Everything is tight on the saw, the carb gaskets/diaphram aren't dried out, and it has a 'spankin new fuel line on it.

Any ideas, where I've screwed the pooch?

Thanks All!

Murf

Take to carb back apart and make sure the impulse diaphragm is against the carb body, it's easy to get the gasket on the wrong side of the diaphragm.

I've run into this a time or 2, and if (IF) the carb is properly assembled, and you remembered to back the Hi and Lo needle appropriately (about 1 to 1.5 turns out each), it's often because the carb pump doesn't work well dry - the checks don't seal well then.

I've solved this one of 2 ways (both successful).

Easy way: Get a syringe and fill it with mix. Insert the syringe in the fuel inlet line, and apply pressure. Sometimes using a paperclip to "tickle" the inlet (metering) diaphragm helps. When the carb's wetted, all goes well.

Hard way: open the pumper and metering covers. Wet inside both with mix. Reassemble.

If this doesn't work, you've likely got an assembly error, bad pulse line, or plugged part.

J

Yup, I'm about convinced I need to take the carb apart....AGAIN! and check everything out.

Good Idea on the syringe JasonBmac, I'll try that!
And Yes, I started at 1/2 a turn out on both needles, and about every couple of times it fired I'd give both another 1/2 turn. Seriously, I'm now at about 4 whole turns out on both needles! Yeah, probably way too much!

Thanks fellas, Anyone else?

Murf

mastermind7864 said:

Take to carb back apart and make sure the impulse diaphragm is against the carb body, it's easy to get the gasket on the wrong side of the diaphragm.

Click to expand...

:agree2: My first thought.opcorn:

You can stick your thumb over the throat of the carb to help along the priming process...it increases the vacuum on the diaphragm...sometimes it works too...lol

Tried that too, although only while cranking, and not while it was running (briefly!)
Although I don't suspect it would make a whole lotta difference?!?!

Thanks again!

Murf

The pumper and metering areas must be the two opposite sides of the carb?
Pumper has to be the side where inlet is, so the metering side must be the other side? The pumper side has the inlet needle and seat?
I ask this because I have been having the same kind of problem, where the saw runs when mix is squirted into the carb, but won't suck up the gas, even when choked, to keep running. And the carb is clean inside.
So are the small flaps supposed to seal the holes under them?
Thanks

Go here everything you need to know about the WT Walbro carbs.



http://wem.walbro.com/distributors/servicemanuals/WTseries.pdf

did you follow the directions in Brads thread about the modification to the impulse passages on the carb so that it lines up with the one on the saw? No impulse no pumping of fuel

mastermind7864 said:

Go here everything you need to know about the WT Walbro carbs.



http://wem.walbro.com/distributors/servicemanuals/WTseries.pdf

Click to expand...

Thanks for posting that!...rep for ye.

ironman_gq said:

did you follow the directions in Brads thread about the modification to the impulse passages on the carb so that it lines up with the one on the saw? No impulse no pumping of fuel

Click to expand...

Hmmm, Didn't see anything in the thread I posted about altering the impulse passages.

Wouldn't happen to know which thread it was in do ya?

Thanks!

Murf

http://www.arboristsite.com/showthread.php?t=74899&highlight=ported+ms180

Theres a recap about what you need to do on page 6.

I think that's gotta be it Ironman!

Thanks for the link! Without that I'da NEVER figured that out.

I'll give it a shot and see how it works!

thanks again.

Murf