Thread: How Does A Fuel Vent Valve Work? Partner Saw.......

Hello,

I'm not real familiar with fuel venting on saws. The only vents i've been aware of are the vented caps on those 600-series Macs. Awhile ago I found the far end of the fuel vent hose on my Partner P100/Mac PM1000 had rotted off, it's seen a lot of sitting. I located an IPL for the P100 and one for the PM1000. Called over to Wallenberg's to see if they could help me out. I told them I wanted the whole fuel vent hose assembly from the tank out. Can't remember if I gave them part numbers or not. On shipment, I received a nipple piece, a hose, and a round strainer screen. I called back and asked in what format the parts went together onto the tank. He thought the strainer stopped the fuel from coming out. That made sense to me as the 600-series Macs have a strainer in the cap. Unfortunately, he couldn't tell me 100% for sure, and his mechanic wasn't in, and whenever I call now for some reason his mechanic isn't in. So I went to install stuff today. I inserted the strainer screen into the one end of the hose, and I noticed that the nipple piece he sent was the same piece as was stuck into the grommet in the tank, so I just made sure mine was open and reused it. Figuring this was correct, I installed it and tested it for seaping. Looked good when I put the hose in the firewall holder. I tipped the saw on the recoil side to pull out the spark arrestor, and after about 5 minutes started smelling fuel. Sure enough, my stainless top on my toolbox was soaked in fuel. It was wet by the strainer end, as well as the grommet end, but that may just be from feeding from one of the ends.

After searching awhile, there is a lot mentioned about a one-way valve in those types of venting systems (hose vents). I did notice tonight on the IPL that there is another piece at the far end of the hose after the strainer. Does that work in series with the strainer, or is the strainer a stand-alone piece? What benefit would the strainer be if there was a valve after it? Really just would like to hear some insight on how this works.

I'm really no expert at these saws, or any saws, but more of an enthusiast. So I appreciate the friendly advice if anyone has any. (I will keep searching, for those that might mention to search more.)

Thanks

Can you post pictures of the parts in question and the IPL? Some vents will leak a small amount of fuel when a saw has been on its side for awhile. I had ordered some Mac parts through Harry W back in May. They sent me two 1/4"-20 nuts instead of 2 Mac bar nuts and I am still waiting. Makes me appreciate the outstanding customer service of Bailey's even more.

Fuzzy memory.

The Partner vents had a brass tube about a 1/2 long that went into the hose that attached to the nipple in the tank. In the tube there was a duck bill check valve. The duck bill check valve had to be installed in such a manner that it let air in but did not let gas out. The end of the hose that was not attached to anything was plugged with a brass or plastic mess plug to keep the tube from collecting dust and plugging the duck bill. If they did not send you a tube with the brass check valve then fuel will just pour out the hose.

If your old hose has the brass tube in it you can re-use it after putting a new duck bill in it. It is a pain but better than nothing.

Originally Posted by Urbicide

Can you post pictures of the parts in question and the IPL? Some vents will leak a small amount of fuel when a saw has been on its side for awhile. I had ordered some Mac parts through Harry W back in May. They sent me two 1/4"-20 nuts instead of 2 Mac bar nuts and I am still waiting. Makes me appreciate the outstanding customer service of Bailey's even more.

Sure, would be glad to. I'll run out to the shop and get some pics snapped, and upload them right away.

The IPL's that I have are saved in PDF form. I'll see if I can "Print Screen" the page(s) for each IPL and upload them with the pics.

Thanks for the support!

Originally Posted by Justsaws

Fuzzy memory.

The Partner vents had a brass tube about a 1/2 long that went into the hose that attached to the nipple in the tank. In the tube there was a duck bill check valve. The duck bill check valve had to be installed in such a manner that it let air in but did not let gas out. The end of the hose that was not attached to anything was plugged with a brass or plastic mess plug to keep the tube from collecting dust and plugging the duck bill. If they did not send you a tube with the brass check valve then fuel will just pour out the hose.

If your old hose has the brass tube in it you can re-use it after putting a new duck bill in it. It is a pain but better than nothing.

Hi Justsaws,

I'm having trouble picturing the brass tube you're referring to.

They sent me the transparent hose, then a round brass-colored screen (I call a strainer), and then the nipple that goes into the tank. Now that I think of it, when I first called him after I got the package, he said he didn't know what was shipped. Said something about his mechanic putting the parts order together for me. ????? I know when I ordered I went through the lady first, then Harry called me back rather than her, and he finalized the order. When I first opened up the package, I thought that nipple was the check valve. Didn't think anything of it, until I looked through it today. First off it was the same size as the nipple into the tank, secondly there was no ball valve in it. I thought I had seen some restriction in it, turns out it was just debris.

http://cgi.ebay.com/Partner-P55-P70-...3286.m20.l1116

Here's that nipple I was speaking of. Scott lists it as the tank vent, but in the Partner IPL, they show that P/N as the nipple that inserts into the tank grommet, which is just a union fitting in principle. I actually purchased this exact part from Scott before I called Harry. Looking at it tonight, it's the same piece that was in the tank grommet, and it is also the exact piece that Harry sent. Unfortunately, it's a completely open passageway, so it's not a tank valve. So now I have three of them, completely good, but they vent more than air.

I'll run out and snap some pics. I was going to take some earlier, but I had an emergency run for the house. We had a huge storm that all of a sudden came up. I was watching it out of the shop while I was cleaning up the gas spill. I could see it coming across the field, all of a sudden the farm to the west was totally invisible. Everything was blowing I could tell the storm was crossing our road from the west. Had a tornado come through here about 17 yrs ago, chased my grandparents out of the same shop that I was in. Took the walls out of that shop, took some bins, and took the barns. I forgot the amount of yrs they say that a tornado is more apt to come back to the area, but I wasn't taking any chances. It was a lightening dash to the house!

It looks like you need the actual check valve. The hose on the out side of the tank is 8" long and attaches to the white carb box baffle crossing from the flywheel side to the clutch side of the saw above the carb. The brass check valve is in that hose about 4" in from the loose end and the brass mesh is in the loose end of that hose maybe an 1". If this does not seem right than I may be thinking about the wrong series of saw.

A lot of times as the hose aged and cracked it would get shorter and pieces started to disappear. If you can not find one for the Partner there are other in line check valves that can be used. What is your closest dealer?

Originally Posted by Justsaws

It looks like you need the actual check valve. The hose on the out side of the tank is 8" long and attaches to the white carb box baffle crossing from the flywheel side to the clutch side of the saw above the carb. The brass check valve is in that hose about 4" in from the loose end and the brass mesh is in the loose end of that hose maybe an 1". If this does not seem right than I may be thinking about the wrong series of saw.

A lot of times as the hose aged and cracked it would get shorter and pieces started to disappear. If you can not find one for the Partner there are other in line check valves that can be used. What is your closest dealer?

Yup, I think you have the right series. That is about the length of the hose, and the hose clips in a retainer on a white firewall around the intake. Of course the IPL doesn't show how parts go together, so I wasn't confident in how things were layed out.

I'm not sure where my closest Partner dealer is. I deal through a local hardware store. I've got my Jonsered in there now, as I was having issues deciphering the IPL on that too, and I figured he's got the parts access, so i'll let him play with it. How ironic, that's also in their for a fuel vent issue. The poor part, he's usually busy it seems, and he generally wants me to find part numbers for him. When I brought up about the fuel vent, he asked for part numbers. At that time all I had was the Partner numbers, and he couldn't get anything from them, so he sent me to Harry.

I'm gonna go get those pics now. Seriously!

On saws with the vent on the outside of the tank attached to a hose there are lots of options from most of the brands. It does not need to be brand specific. An exterior tank vent check valve from an Echo weed wacker(modified) will work as will one from a 2095 Jonsered. Poke around the guys junk pile and see what is available.

If you find a duck bill housing with a bad duck bill, start looking at the gas tank caps with the vents in them. Pull the vent filter out and remove the duck bill and then install it into the proper housing.

You can make them from fuel filters and duck bills and carb parts and duck bills.

Also most common sized duck bills are still available and can be order.

OK, got some pics. Hopefully they will be uploaded within the hour. And the IPL's. Got some part numbers as well.

OK, here's some pictures that I uploaded of how it is setup now. I'll post P/N's of what I have following.

P/N's (All of the descriptions are what the invoice says.)

310741 - Vent Hose

312786 - Air Vent

315173 - Vent Strainer

Those must be the Partner numbers, as they match up to what the IPL shows. It also shows those numbers to be the correct components. It would be strange, though, that the tank vent on the outward end would be the same as the nipple into the tank, as well as them both having different P/N's. If that would be the correct part, does it pose any restriction or valve operation in series with the strainer, since it is an open passageway?

32090 -looks like they are putting the duck bill in the tank.
-could just be a chunk of hose to seal the tank. That is what I remember.

32132 -looks like the adapter.

32292 -Vent Hose.

32134 -Clamp to attach hose to housing.

32139 -That looks like the brass fitting with the duck bill in it.

32245 -Brass mesh.

Hard for me to read the IPL but that is my best guess. I do not think that you recieved all the parts you need. You might try putting a duck bill on the brass adaptor on the inside of the gas tank. Should work. That looks to be what the IPL shows. I have not seen that but I have only seen used and abused Partner saws. They also could have up-dated and changed the vent position.

There has to be a duck bill check valve in line in order to seal off the gas tank.

My guess is that 32090 is the black grommet that holds the 32132 adapter fitting into the tank. That end i'm pretty familiar with, but the other end must be the issue. Why the 32245 (312786 Partner P/N) that they sent me is the exact same thing as the hose adapter to the tank is beyond me. Maybe they had a mix-up in the parts bin, or a mix-up when putting the order together.

If I could figure out the function of the strainer, that would help. I know it was a pain to get it as far in the hose as I did. I can't bear to think of having to shove it in far enough to get a check valve in the hose behind it.

Apparently if I had the right piece for the far end of the hose, my troubles would be over.

In the first picture you see how the hose in pushed into the side of the white housing, the brass mesh needs to be pushed further into the hose and the hose itself cut at an angle so that the housing cannot get covered with a mixture of fuel and wood dust and block off the end of the hose.

Also you should replace the fuel line. It looks way past safe.

Great looking saw. A good collectors example.

Originally Posted by ProMac1K

My guess is that 32090 is the black grommet that holds the 32132 adapter fitting into the tank. That end i'm pretty familiar with, but the other end must be the issue. Why the 32245 (312786 Partner P/N) that they sent me is the exact same thing as the hose adapter to the tank is beyond me. Maybe they had a mix-up in the parts bin, or a mix-up when putting the order together.

If I could figure out the function of the strainer, that would help. I know it was a pain to get it as far in the hose as I did. I can't bear to think of having to shove it in far enough to get a check valve in the hose behind it.

Apparently if I had the right piece for the far end of the hose, my troubles would be over.

I am familiar with the grommet as well. I do think that you have received the wrong part as the check valve looks like a brass tube with the ends barely crimped.

The strainer is just a filter to keep wood dust out of the hose. It is the last thing in the hose. The check valve goes in front of the strainer and yes it is a pain. Grease up the parts before trying to install them.