Colt Case Ingersoll Garden Tractors

It is hotter than blazes here today. Upper 90s high humidity. As we were running the 648 around today it started having trouble running. It appears to be a fuel problem as I can choke it and keep it idling. Im thinking it’s vapor locking. I put new gas line in when we got it going and every thing was fine, but it wasn’t hot out. Have you guys had this problem? What kind of gas line are you running? I could have sucked some junk in carb too I guess. I didn’t have time to look at it today. Something else to add to the list to check out!

I can says I ever had a vapor lock in any of my tractors. That I know of. But have heard about it before. We get 85/90F here at times. I’d be guessing dirt in something. Hope you get it figured out. And if it is vapor lock, how did you fix it.

Noel

I had a 442 that liked to vapor lock just like that. You may have to look at some shielding or ventilation to keep the fuel lines cool. Specifically you're trying to be sure that the heat from the exhaust can't reach the fuel lines.

Bob

@JSinMO The Onans are known for intake leaks at the seam where the two halve meet. The higher temps could be bring it out. Also the extra heat could be affecting the coil weakening the spark . A richer mixture is easier to jump the gap . I do you know how to use propane to check for vacumm leaks ? I would do that first .

DavidBarkey wrote: ↑Mon Jun 13, 2022 6:54 am @JSinMO The Onans are known for intake leaks at the seam where the two halve meet. The higher temps could be bring it out. Also the extra heat could be affecting the coil weakening the spark . A richer mixture is easier to jump the gap . I do you know how to use propane to check for vacumm leaks ? I would do that first .

When we got it running I made new intake gaskets and resealed the seam with high temp gasket sealer. I’ve never used propane to check for leaks, but I’ve used carb cleaner to do it. I’ll check it next time we run it. I should probably go over the intake bolts too.
Thanks.

I don't know if you already checked the gas tank and or fuel line for debris. Most of us also have a little inline fuel filter. Hope you make sense of it soon!

I just went up and started it this morning with everything cold. Sure enough it starts right up runs to full throttle and work perfectly. This convinces me I have a heat related problem, and I think it’s fuel delivery.
When we got it running I had the tank off to patch a couple of holes in it. Its been cleaned out. I replaced the gas lines from the tank to the carburetor, and I’m running two filters. This has an electric fuel pump, I put 1 filter before the pump and 1 after.
I don’t think it’s a spark issue because when it happens I can get the tractor to idle with full choke.

I should be able to do a couple of easy tests if it happens again. I can check the intake for leaks, or reroute the gas line. Right now I have it routed through the engine compartment to the carb. I can run it outside of the engine and see it it changes. If it happens again, I’ll report my findings.

Oh! So it's clear that clean fuel gets to the carburetor. Seems like the problem really is that the air/fuel ratio gets too lean when the engine is hot. As it runs on the lean side the engine will also overheat, making the problem probably worse. If all the engine shrouds are in place and the engine has good air flow, then what's left is the intake, but you said you already rebuilt that. I'm also assuming the muffler and exhaust pipes are separated by tin from the engine, as that's how it is on my 446 Onan for instance. You have a good puzzle on your hands

As you know, I don’t have any experience with vapor lock. You say it idles with full choke when it takes its fit. If it was vapor locked, doesn't that mean no fuel is getting to the carb ? So how would it idle if that’s the Case.
Just wondering.


Noel

That's exactly how my 442 behaved when vapor lock happened. The vapor locking causes a fuel shortage, and by choking it you can increase your fuel "suction" to keep the engine running, albeit poorly. This sounds precisely like vapor lock to me.

Bob

thebuildist wrote: ↑Mon Jun 13, 2022 6:54 pm That's exactly how my 442 behaved when vapor lock happened. The vapor locking causes a fuel shortage, and by choking it you can increase your fuel "suction" to keep the engine running, albeit poorly. This sounds precisely like vapor lock to me.

Bob

Seems to me this is what’s happening. Even with full choke it barely runs. If you try to do anything other than keep it running it will die.

To update this I ran it some today and it happened again. I didn’t have a lot of time to dig into it, but I did check a couple of things.

I checked the fuel pump and it is working fine.
Then I moved the gas line and took the curve out of it to the carburetor as much as possible. Tractor started up and ran better with no choke. This is new fuel line but I don’t think it can handle the heat. The line right at the carburetor feels very soft, I can pinch it shut with very little pressure. This would explained what happening.

So as soon as I can get to a store I think I’ll look for some copper line to replace the rubber hose and run it out of the engine compartment as quickly as possible.
On the old tractors guys used to make a couple of coils in the line to try to keep the fuel cool on the way to the carburetor, I might try that too as there really seems to be quite a bit of heat build up under the hood.

I’ll update this when it get it changed.

Still not making sense to me. As I’ve said. I have no experience with this. But, if it’s a vapour lock, that means a space some where in the system has vapour not liquid in it. If the carb bowl was down on fuel, that would mean the needle is open and fuel should run in. The bowl in the carb has to have a atmospheric hole in it to allow gas in to the bowl while vapours get pushed out. The electric fuel pump should be able to do that. It’s pressurizing the fuel to the carb and should be able to push fuel into to the carb bowl. If the atmospheric hole in the carb is not plugged. Then the needle will close to stop fuel coming in.


Jumpins. That was quite a ramble. Beat that Eugen.


Noel

JSinMO wrote: ↑Mon Jun 13, 2022 7:34 pm
So as soon as I can get to a store I think I’ll look for some copper line to replace the rubber hose and run it out of the engine compartment as quickly as possible.
On the old tractors guys used to make a couple of coils in the line to try to keep the fuel cool on the way to the carburetor, I might try that too as there really seems to be quite a bit of heat build up under the hood.

I’ll update this when it get it changed.

If you go with a copper line, you might sheath it in rubber hose down near the engine, so the rubber acts as insulation to keep the copper from heating up.

Bob

thebuildist wrote: ↑Mon Jun 13, 2022 8:41 pm

JSinMO wrote: ↑Mon Jun 13, 2022 7:34 pm
So as soon as I can get to a store I think I’ll look for some copper line to replace the rubber hose and run it out of the engine compartment as quickly as possible.
On the old tractors guys used to make a couple of coils in the line to try to keep the fuel cool on the way to the carburetor, I might try that too as there really seems to be quite a bit of heat build up under the hood.

I’ll update this when it get it changed.

If you go with a copper line, you might sheath it in rubber hose down near the engine, so the rubber acts as insulation to keep the copper from heating up.

Bob

That’s what I was thinking too.

Propane57 wrote: ↑Mon Jun 13, 2022 7:57 pm Still not making sense to me. As I’ve said. I have no experience with this. But, if it’s a vapour lock, that means a space some where in the system has vapour not liquid in it. If the carb bowl was down on fuel, that would mean the needle is open and fuel should run in. The bowl in the carb has to have a atmospheric hole in it to allow gas in to the bowl while vapours get pushed out. The electric fuel pump should be able to do that. It’s pressurizing the fuel to the carb and should be able to push fuel into to the carb bowl. If the atmospheric hole in the carb is not plugged. Then the needle will close to stop fuel coming in.


Jumpins. That was quite a ramble. Beat that Eugen.


Noel

Your thinking of it correctly. So the carburetor is working as it should. The needle is opening and calling for fuel to the bowl. The problem is the gas line is partially restricted because its collapsing in the bend in it just before the carburetor. The fuel pump is pressurizing the system, but when the fuel gets to that part of the line, the restriction plus heat is vaporizing the fuel before it makes it to the bowl. In this situation the fuel keeps turning to vapor and never fills the bowl.
That’s why it’s a vapor lock liquid fuel can’t get past it.

I alway worry I’m not explaining things very well, so I hope that makes sense.

JSinMO wrote: ↑Mon Jun 13, 2022 9:06 pm

Propane57 wrote: ↑Mon Jun 13, 2022 7:57 pm Still not making sense to me. As I’ve said. I have no experience with this. But, if it’s a vapour lock, that means a space some where in the system has vapour not liquid in it. If the carb bowl was down on fuel, that would mean the needle is open and fuel should run in. The bowl in the carb has to have a atmospheric hole in it to allow gas in to the bowl while vapours get pushed out. The electric fuel pump should be able to do that. It’s pressurizing the fuel to the carb and should be able to push fuel into to the carb bowl. If the atmospheric hole in the carb is not plugged. Then the needle will close to stop fuel coming in.


Jumpins. That was quite a ramble. Beat that Eugen.


Noel

Your thinking of it correctly. So the carburetor is working as it should. The needle is opening and calling for fuel to the bowl. The problem is the gas line is partially restricted because its collapsing in the bend in it just before the carburetor. The fuel pump is pressurizing the system, but when the fuel get that part of the line, the restriction plus heat is vaporizing the fuel before it makes it to the bowl. In this situation the fuel keeps turning to vapor and never fill the bowl.
That why it’s a vapor lock liquid fuel can’t get past it.

I alway worry I’m not explaining things very well, so I hope that makes sense.

This is why the engine will try to idle with full choke, it’s literally trying to run on fumes.

Ok, I got it now. Thanks.


Noel

@JSinMO Instead of copper line , what about fuel injection hose . Double walled stronger hose.

Here’s another ramble for you. If you use copper line, and cover it with another line, rubber, plastic or what ever. I would get the covering line much bigger than the copper line. That way you have an air space. And leave it open on both ends. Have the end farthest away from the carb as low as you can get it. This will cause a venting action in the covering hose. As things get hot the hot air will rise and draw cooler air in from the bottom to help cool the copper pipe. If you have the covering line tight to the copper, the copper will draw the heat in from the covering pipe.


Noel

After reading what he found , I don't thing heat persay is the issue . There are many here with these 646/8 that are not having the same problem . I have side panels on Frankie's hood and work him hard and don't have that issue with a P220 onan . I think that the quality of line just is not up to scratch for this application . I have had to use fuel injection hose instead of lose pressure hose in some applications due to the poor quality hose these days kinking or collapsing . My 2 cents , You may keep the change .

DavidBarkey wrote: ↑Tue Jun 14, 2022 7:53 am After reading what he found , I don't thing heat persay is the issue . There are many here with these 646/8 that are not having the same problem . I have side panels on Frankie's hood and work him hard and don't have that issue with a P220 onan . I think that the quality of line just is not up to scratch for this application . I have had to use fuel injection hose instead of lose pressure hose in some applications due to the poor quality hose these days kinking or collapsing . My 2 cents , You may keep the change .

I’ve rolled this around in my head 4 time more than I probably need to. I think you hit the nail on the head.
Do I have a fuel delivery problem? Yes.

Is this a vapor lock situation or heat related? Probably.

What is the root cause? Just what you said. That line I put in is not up to the job. Not the correct line for this application.

After reading what Bob, and Noel wrote about insulating the copper line if I went that route, I decided to take your 2 cents. I stopped at the parts store today and picked fuel injection line.

Hopefully I’ll have time later in the week to switch it out and we’ll see how it runs.

Thanks for taking a look at this with me guys. I appreciate your comments and thoughts!

I think that's most likely the solution Jeff, please let us know if it fixed the issue!

Let me start by saying I have no problem admitting when I’m wrong. If you can’t accept it when a theory is incorrect you’ll never learn anything, and you won’t fix anything!
Secondly I’d like to say…CRAP!

I went up to the shop tonight to fiddle with this. It’s 90 degrees with high humidity so I figured it a good time to see what happens. I replaced the gas line and hooked everything back up and went for a drive. It ran good and I thought I had it whipped. I let it idle for a bit then I ran it again. Same thing happened, it sputtered and died. I could start it back up almost immediately but I have to choke it to get it to start and it keeps dying. I took the air cleaner lid off and started it and I can see gas flowing into the throat of the carburetor. So now I’m not sure what’s going on. I reread what you guys wrote and I think the next plan of attack will be to pull the carburetor and intake and reinspect and go over everything. This issue doesn’t happen until everything is good and hot. I also could keep it running by squirting carb cleaner into the throat of the carb, making me think I have a pretty good air leak somewhere. I sprayed a around the intake and didn’t get any change, but I may not have hit the right spot.

At this point I’m still not leaning toward a spark issue. My experience with a bad coil has been that you can’t restart until its cold. You can restart this the whole time but it only runs for a little bit and sputters and dies.

That’s where I stopped for tonight. We’ll see what happens next!

That's too bad Jeff! It's like this sometimes. Hope you'll find out what's wrong soon!

Your bug seems to have jumped over the border and bit my 644. When it gets really hot it starts lowering the rpm until it shuts down completely. I can start it for a bit with more choke, but then it dies again. It so happens that my fuel line is about 3 inches away from the exhaust pipe.

Gas cap plugged. Take the cap off and try it.

Noel

@JSinMO Before use do anything else check the pulse hose from the crank case to the fuel pump on the carb . And yes verify the gas cap can breathe small insects will build nest in them at times. Verify the screws holding the pump together are all snugg.

DavidBarkey wrote: ↑Sat Jun 18, 2022 6:30 am @JSinMO Before use do anything else check the pulse hose from the crank case to the fuel pump on the carb . And yes verify the gas cap can breathe small insects will build nest in them at times. Verify the screws holding the pump together are all snugg.

Isn’t there an electric fuel pump on this Dave ? Maybe I’m not readin right.

Noel

Yes it has an electric fuel pump on it. I don’t really like the location the PO picked to mount it, but it works so I left it

We’ll tonight I verified the gas cap is not the issue. I ran the tractor until it started acting up again. Same results with or without the gas cap. I also sprayed around the intake with carb cleaner and it didn’t help. I could keep it running by dribbling carb cleaner down the throat of the carburetor. I’m trying to fit a little troubleshooting in between other things I’m doing. I’ll just keep checking things off one by one as I can. Sooner or later I’m gonna find the issue!

Well. Some more thoughts. But I’m running out.

I don’t like the two filters. Could be added resistance there. And I’m not sure if the filters are correct ones. And do they have arrows on them showing direction of flow ? I had trouble with my 224 last year when I got it. I put one of those types of clear plastic filters on and could not get gas to the carb. K321 engine with mechanical original fuel pump. I had to change the filter to an all white not clear filter. Then it worked fine. I’ll find a picture of it soon. Small engine fella explained the differences, but I can’t remember now.

Maybe the fuel pump is getting hot and slowing down or stopping. Charging voltage to low to run pump ??

Lastly, float not set right. Not enough gas in bowl. And as I mentioned before, the atmospheric vent hole in float bowl plugged.

Quite a ramble for a early Sunday morning. Just some thoughts I had. Hope you find the trouble.


Noel

@JSinMO Do you have a low pressure fuel guage you could "tee" in at the carb? That would help solve what is going on . If the flow drops at the carb. so will the pressure. It would need to be a 0-5 lbs guage . A KV. ignion tester would help as well . If the KV's go up when acting up then it is lean . If the Kv's go down You are losing spark or it is rich and with adding fuel helps you know that is not going rich . Other thing that can happen when hot is loosing compression due to lack of clearance at the valves . As the valves heat up use lose clearance . As flat head engine valve seats wear you loose gap . A compression test cold then hot will tell a lot .
Hope this help you find it soon .

DavidBarkey wrote: ↑Sun Jun 19, 2022 7:41 am @JSinMO Do you have a low pressure fuel guage you could "tee" in at the carb? That would help solve what is going on . If the flow drops at the carb. so will the pressure. It would need to be a 0-5 lbs guage . A KV. ignion tester would help as well . If the KV's go up when acting up then it is lean . If the Kv's go down You are losing spark or it is rich and with adding fuel helps you know that is not going rich . Other thing that can happen when hot is loosing compression due to lack of clearance at the valves . As the valves heat up use lose clearance . As flat head engine valve seats wear you loose gap . A compression test cold then hot will tell a lot .
Hope this help you find it soon .

I don’t have a fuel gauge or an ignition tester. It may be time to get them though. I’m sorry im giving short updates, but that’s how im working on it, a little here and there.

I had some time today to mess with it and as soon as it started acting up I pulled the top off the carburetor. The bowl was dry. I checked the fuel pump and it is working I can pull the gas line off of the carb, turn the key on and pump the bowl full close it up, and start the tractor right up. It runs until the bowl is dry again. So my trouble would
seem to be at the carburetor.

I took the top back off and turned the key on and gas was pumping into the carb, but when I put the top back on it’s not making it into the bowl. The needle and seat seem to be ok and I haven’t changed the float at all, but I’m thinking I may need a rebuild kit. I checked all the orifice in the carb body and they seem to open.

It’s not fixed yet but at least I’m narrowing the trouble down.

Check and make sure the tip has not come off the needle and the fuel passage way in the top of carb is clear. Also check the bowl vent again. If the fuel is coming out of the base when top is off then you have an obstruction in the top or it cant vent .

Spent some time this evening fiddling with this again. I ran the tractor again until it died. Took the top off the carburetor and it’s dry. I took a look at the top of the carburetor and didn’t really see anything out of place. I took the needle, seat, and float apart nothing to see here, it look good. I checked the top of the carburetor again, the ports and vent and fuel inlet are clean and open. I know I’m not getting fuel, and I know the pump and hose are good, the fuel cap is not the problem, I took 1 of the filters out of the line, so what the heck?

I decided to do the obvious wrong thing to get it straight in my mind, and eliminate a vent problem. I left the needle and seat, and float out and put the top back on and turned the key. Now what you are thinking happened did happen. The carburetor filled up and gas poured out through the vent.

I put everything back together and decided to adjust the float. We’ll what do you know, after adjusting it a couple of time it runs great again. I ran it all around, let it sit, started it back up and drove it some more, and no problems!

So did I fix it? I guess so, but this raises questions I don’t have answers to.
Why did this start all of a sudden?
Why did it only seem to happen when hot?
The cross bar on the float is pretty thin, can heat affect the float setting?

As of now we’ll run it and see what happens but so far so good!

Yea, that’s good news.


Noel

I'm thinking if the pump is fine, it supplies gas to the bowl. Was the bowl dry when you opened up the carb? What if the needle/float get stuck in a shut position when the engine is very hot? The needle usually has a rubber conical tip, maybe it gets stuck in the seat?

Eugen wrote: ↑Wed Jun 22, 2022 8:58 pm I'm thinking if the pump is fine, it supplies gas to the bowl. Was the bowl dry when you opened up the carb? What if the needle/float get stuck in a shut position when the engine is very hot? The needle usually has a rubber conical tip, maybe it gets stuck in the seat?

Yes the bowl was dry. And yes the needle is rubber tipped. I did spend some time cleaning the seat. It’s possible the needle was sticking when hot. That explication is as good as anything I can think of.

That's a clear smoking gun for me. Pump works, bowl dry, means the venturi mechanism of the carburetor used up the gas in the bowl and the float mechanism didn't allow new gas to come in. Either the hinge on the float gets stuck somehow or the needle. In the end it doesn't matter, if it works fine now is all that matters.

Mine behaves like yours, when it gets really really got, the engine wants more choke to keep going, and then it stops. I'll have to take the bowl off just like you and check next time it does it.