Check valve

[Lloyd Poff]

I have a zama carb C1Q H17A with a leaking check valve on a homelite XL 1.8 cubic inch. I can't find a part # any where & have searched many places. It is .195 in diameter & .275 long. This is an all plastic case made in 1991 from what I can find on acres internet. If I disassemble the valve to try a new seal it might result in not having any check valve period. The saw will run with the bad valve, but starts hard after getting up to operating temperature if it sets for for 10 minutes. I can hear the check valve leaking after shutting the saw off. I'm thinking of soaking it in brake fluid for a few days to restore the rubber seal, how ever this would be a temporary fix. Any suggestions from members will be greatly appreciated.

 

[heimannm]

Sounds more like a metering needle issue to me. The high speed check valve only comes into play when the saw is running at idle. The check valve does nothing when the saw is stopped, but the metering needle must hold pressure.

Mark

 

[Lloyd Poff]

Thanks for your advice, but when the check valve is tested air passes in both directions which is a no no. Needle valve holds 10 psi vaccum. Soaking check valve in brake fluid too see if that will restore the one way function. There are many homelite check valves available with no specs on diameter. Mine is .195. It's like looking for a needle in a haystack. Called zama & they were no help.

 

[SteveSr]

Thanks for your advice, but when the check valve is tested air passes in both directions which is a no no.

How are you testing this? And insuring that you don't have a leak there?

Needle valve holds 10 psi vaccum.

Wrong! Don't know what you are testing. The carb fuel inlet must hold 10 psi pressure indefinitely.

The saw will run with the bad valve, but starts hard after getting up to operating temperature if it sets for for 10 minutes. I can hear the check valve leaking after shutting the saw off.

You won't be hearing the nozzle check valve. You're hearing something else like tank pressurization leaking through the tank vent. After 10 minutes the saw is heat soaked and it sounds like vaporlock, especially if you are still using winter blended fuel on a hot day.

Soaking check valve in brake fluid too see if that will restore the one way function. There are many homelite check valves available with no specs on diameter. Mine is .195. It's like looking for a needle in a haystack. Called zama & they were no help.

The carb is a Zama C1Q. I expect that they all use the same main nozzle / check valve. BTW, when changing them they should be pulled out on the metering side to prevent creating a leak into venturi by pressing the old one in. Also be sure to remove the "H" needle.

 

[Okie]

Go on fleece bay and put up two or three saved searches saved searches so as you will get a email message when one appears.
Your description issue does not sound like a check valve issue but
I've seen posts on here about how to make check valves.
I've bought check valves on fleece bay for the homelite carb,s but I had to remove the old one first to determine size etc, then go on fleece bay and look at pictures to get correct replacement.
I've flogged them Homie zama carbs and at times I've just had to install another carb to get a good run. Them little 2 cycle carbs can sometimes make you feel weak upstairs.

 

[Lloyd Poff]

Go on fleece bay and put up tow or three saved searches saved searches so as you will get a email message when one appears.
Your description issue does not sound like a check valve issue but
I've seen posts on here about how to make check valves.
I've bought check valves on fleece bay for the homelite carb,s but I had to remove the old one first to determine size etc, then go on fleece bay and look at pictures to get correct replacement.
I've flogged them Homie zama carbs and at times I've just had to install another carb to get a good run. Them little 2 cycle carbs can sometimes make you feel weak upstairs.

Thanks for your reply, I have an old M1 zama carb & the check valve is bigger in diameter, dang the luck. Just soaked the check valve in brake fluid for a day & a half. check valve is holding, but the brake fluid treatment is only a temporary fix. So I installed a new needle valve after cleaning the seat with a q tip. Checked all 3 small orifices to make sure they are open. put the old check valve back in with a small amount of sealant & when I can get the time will put it all back together & see the results. So far all I have found faulty is the check valve. In a few days I will let you know how this turns out. The noise I heard was exactly like you hear when you are testing a check valve with a piece of fuel line. I can hear the audible click just like I hear through the saw on the muffler side. Can't be the fuel tank as it has a duck valve in the tank as the primer bulb is on the fuel tank. I have never heard any noise come from a rubber duck valve lol I found a check valve at a farm supply store that looks like a possibility, but they were not interested in measuring the diameter. Well I will try your suggestion on fleece bay & see what happens. This model of homelite is hard to find a parts list that gives the part number. No luck so far. They must be ashamed of this little saw lol. Sure wish it was equipped with a walbro carb.

 

[J D]

The valve part of the check valve is just a small disc that floats around inside the housing. I believe it's possible to fish that out & punch a new one out of the diaphragm material from the pump side of a carb & carefully work it into the housing. Never done so myself but I've seen posts where people claim to have done it successfully

 

[Old2stroke]

The valve part of the check valve is just a small disc that floats around inside the housing. I believe it's possible to fish that out & punch a new one out of the diaphragm material from the pump side of a carb & carefully work it into the housing. Never done so myself but I've seen posts where people claim to have done it successfully

Yep, lots of us repair those pesky valves. Just has to do a search on "repair nozzle check valve".

 

[Lloyd Poff]

The valve part of the check valve is just a small disc that floats around inside the housing. I believe it's possible to fish that out & punch a new one out of the diaphragm material from the pump side of a carb & carefully work it into the housing. Never done so myself but I've seen posts where people claim to have done it successfully

I have done that very thing on a Walbro carb. Probably will end up doing the same thing on this crappy zama carb. Thanks for your post.

 

[Old2stroke]

I have done that very thing on a Walbro carb. Probably will end up doing the same thing on this crappy zama carb. Thanks for your post.

The valves that have a flexible rubber disc are easy to repair but some zama carbs have a rigid fibre disc and might not be so easy

 

[SteveSr]

The valves that have a flexible rubber disc are easy to repair but some zama carbs have a rigid fibre disc and might not be so easy

I think that I have only seen fiber in Zama which is not repairable except with a new nozzle. The fiber starts coming apart and causes the valve to start sticking.

 

[Lloyd Poff]

The valves that have a flexible rubber disc are easy to repair but some zama carbs have a rigid fibre disc and might not be so easy

Thanks for the info, leave it to zama to mess things up. I soaked this valve in brake fluid & it improved, so maybe I will luck out with a rubber disc.

 

[Vintage Engine Repairs]

Are you testing that valve having saturated it with fuel?

 

[Lloyd Poff]

Are you testing that valve having saturated it with fuel?

Saturated with brake fluid

 

[Lloyd Poff]

Finally found the correct check valve for C1Q H17A carburetor on Repair Clinic web page. It is Genuine OEM Part # A007190. Hope this information will help some one. After a new carb kit with spacer gaskets & new diaphragms with new needle valve, spring & metering lever I'm hoping the little homelite XL runs like new. This is a strange carburetor & glad to find a new check valve. I bought the last check valve in stock. Got lucky for once.

 

[SteveSr]

Finally found the correct check valve for C1Q H17A carburetor on Repair Clinic web page. It is Genuine OEM Part # A007190. Hope this information will help some one. After a new carb kit with spacer gaskets & new diaphragms with new needle valve, spring & metering lever I'm hoping the little homelite XL runs like new. This is a strange carburetor & glad to find a new check valve. I bought the last check valve in stock. Got lucky for once.

What makes you think that A007190 is the correct part number? The IPL that I posted lists A007024 for the H17A. This part number isn't listed in either the current or 2012 price list so it was either obsolete by 2012 or it was, more likely, a proprietary part for Homelite.

@heimannm may know more...

 

[Lloyd Poff]

I have the valve & it's identical to the original. Plus when doing the search Repair Clinic specifically stated it fits the C1Q H17A.

 

[Lloyd Poff]

What makes you think that A007190 is the correct part number? The IPL that I posted lists A007024 for the H17A. This part number isn't listed in either the current or 2012 price list so it was either obsolete by 2012 or it was, more likely, a proprietary part for Homelite.

@heimannm may know more...

Item# ZA-A007024 ZA Part number A007024 NOZZLE ASS'Y CHECK VALVE. Replaced by: A007190 This item is part of the superseding sequence A007024

 

[Okie]

Let us know the outcome of how the carb acts?

I've heard rumors that Zama is no longer going to offer carb kits, just complete carbs.

China should chime in on that.

 

[Lloyd Poff]

How are you testing this? And insuring that you don't have a leak there?


Wrong! Don't know what you are testing. The carb fuel inlet must hold 10 psi pressure indefinitely.



You won't be hearing the nozzle check valve. You're hearing something else like tank pressurization leaking through the tank vent. After 10 minutes the saw is heat soaked and it sounds like vaporlock, especially if you are still using winter blended fuel on a hot day.


The carb is a Zama C1Q. I expect that they all use the same main nozzle / check valve. BTW, when changing them they should be pulled out on the metering side to prevent creating a leak into venturi by pressing the old one in. Also be sure to remove the "H" needle.

Let us know the outcome of how the carb acts?

I've heard rumors that Zama is no longer going to offer carb kits, just complete carbs.

China should chime in on that.

Okie, I have thge new check valve installed & new kit installed, have not had time for start up as I'm my wifes full time care giver due to health problems. I'm hoping to start it up later tonight and will let you know the results . Thanks to every one that has commented on this carb project.