031av nonstart after repairs

[Phil_C]

The fuel line running into the carb is bone dry, after it running and being cranked with and without the choke on. The carb is not pulling fuel.

mmmmmmm. might at least consider it.........

You guys did read all of Tait's post, right? Even if the timing is out far enough that there is no kick or backfire or anything with the amount of pulling he has done so far there should be fuel in the carby. Also as Tait mentioned it will run briefly if fuel is poured down through the plug hole.

 

[HarleyT]

Yeah, we have read it. It should run much more than 1/2 of a second, shouldn't it?
The Oregon module looks like this.



At least on this one you can reverse the polarity....
I have had to go back in and switch the wires before to get the saw to run. But on the 031, he will probably have to adjust the flywheel position as well. The Oregon module works on the 032 by just bolting on, but the 031 calls for a different module.

 

[Tait]

You guys did read all of Tait's post, right? Even if the timing is out far enough that there is no kick or backfire or anything with the amount of pulling he has done so far there should be fuel in the carby. Also as Tait mentioned it will run briefly if fuel is poured down through the plug hole.

So I tore the saw apart again last night. I vacuum tested the impulse line. It held vacuum. I inspected the carb elbow. No cracks and is still quite pliable. I know schematics are specific to the carb in question, but I had this saw's carb rebuilt years ago in an attempt to get it started again. The same thing was happening before and after the the previous rebuild. Upon further inspection, I found diaphragm #19 noted below missing from my carb. I only replaced what I found in the carb this go around. If the shop that did the earlier rebuild failed to put this diaphragm in then so did I. After putting this in, I was able to blow air through the fuel inlet if I activated the diaphragm with slight pressure through the atmospheric hole in the plate. Of course it was too late to try to start the saw so will try again.

http://www.*****************/gallery/albums/userpics/34741/walbro.jpg

I figure once I can get the fueling issue I will then have a timing issue. I just want to get it running before I start chasing the timing. From what I have read I need to adjust the timing roughly 20 degrees. Is that clockwise or counter clockwise. Without the key is the flywheel held by pressure alone? I guess I could buy a used electronic flywheel or use a file to cut a new slot in my flywheel once I have the location determined. I could also use a photo of an electronic flywheel to get a good idea of where to start. Thanks again for the input.

 

[295 tramp]

As Harley T stated and I'll probably catch hell for saying IMOA those atom chips are junk. I bought one for a 028 points saw.
When I installed it the saw started right up, but the fuel line had a crack in it and the saw started and went to WOT and died and wouldn't start after that.
It smoked the 35.00 atom chip so I swapped it out for a electronic ignition.

 

[HarleyT]

Well here is a blowup of the Walbro WA2c carb off of the Mediacat 030,031 ipl.

 

[Tait]

Well here is a blowup of the Walbro WA2c carb off of the Mediacat 030,031 ipl.

View attachment 496661

Thanks for the picture. Yep, mine was missing #19. I need to find a copy of the ipl for a few of my Stihl's. Would be good to have.

 

[HarleyT]

Go to the Mediacat chain letter thread, you will love the program.

 

[Tait]

Go to the Mediacat chain letter thread, you will love the program.

Found the thread and posted up. Thanks for the suggestion! That will be very useful to have

 

[Phil_C]

So I tore the saw apart again last night. I vacuum tested the impulse line. It held vacuum. I inspected the carb elbow. No cracks and is still quite pliable. I know schematics are specific to the carb in question, but I had this saw's carb rebuilt years ago in an attempt to get it started again. The same thing was happening before and after the the previous rebuild. Upon further inspection, I found diaphragm #19 noted below missing from my carb. I only replaced what I found in the carb this go around. If the shop that did the earlier rebuild failed to put this diaphragm in then so did I. After putting this in, I was able to blow air through the fuel inlet if I activated the diaphragm with slight pressure through the atmospheric hole in the plate. Of course it was too late to try to start the saw so will try again.

Glad to see you found something. I assume without the gasket there is/was not enough room for the little valves to open.

Heres an 031 electronic flywheel on ebay

When I replaced the points in mine I bought both a new flywheel and the genuine ignition from ebay. I have also had bad experiences with the Atom electronic ignitions. In fact I thought they went out of business or stopped selling them. Any point replacement modules I put on Stihl's are the genuine item though they are getting harder to get.

 

[HarleyT]

Actually #19 is another diaphragm.

 

[Phil_C]

Actually #19 is another diaphragm.

My mistake I should have looked closer and thought about it a bit more For some reason I had it in my head that both 18 and 19 were only gaskets but of course they are not. 18's the gasket and 19 is the suction chamber diaphragm which would explain why no fuel is getting through.

 

[Tait]

I am hopeful tonight she will at least fire up. Now I just need to track down the correct flywheel or purchase the one on eBay. Sounds like I should not plan on the ignition chip I purchased lasting too long. Will keep an eye out for an OEM one. I should have just put this thing on a shelf to look at and purchased a new saw! But, this is kind of fun.

 

[Tait]

She lives!

Took a dozen or so pulls to get fuel down to the carb, but once it was there she popped then started on the next pull and kept running. I have the high and low screws set to default 1 1/4 right now and it sounded pretty good. It was dinner time so had to head inside. Plus the neighbors were outside and I did not want to bother them so will fine tune it this weekend. I hate to think it was just the missing diaphragm this whole time, but at least it is now electronic, has new fuel lines, fuel filter, spark plug, and is all cleaned up. So far, there does not appear to be a timing issue. I will know more this weekend, but it revved up smoothly, was not running lean at wide open throttle and sat idling without a hiccup. Chain oiler was pumping oil. I appreciate all the help and will post up the final details after fine tuning it this weekend.