Oliver 550 won't start.

Hello All.
This is my first post after joining this site! Happy holidays to everyone! 😊
I’ve recently had the privilege of inheriting my grandfather-in-law’s 1968 Oliver 550 tractor with loader. I’m kind of excited because this is my first tractor! You have to start somewhere, I guess.
Over the holidays, I brought the tractor inside a heated garage to try and get her running. To the best of my knowledge, she’s been kept in a covered barn and not been started for 15-20 years!!! She’s WELL used but in remarkable condition after all these years. She was backed into the barn, parked and been sitting there ever since.
I’ve done all the usual things to begin with. Changed all the fluids, changed the spark plugs, verified and cleaned the points & condenser and added some fresh gas. The tank was surprisingly bone dry and perfectly clean! After my first attempt at a start, after putting fresh gas, the carb had gas pouring out the intake as fast as I was adding. No problem. Purchased a complete carb kit and had a local guy perform the clean and rebuild. Everything went well, even the float was in great condition.
On the 2nd attempt, she turns over very well. Avg 150 compression in each cylinder. Correct firing order of 1-2-4-3. Very good spark. She just absolutely refuses to start. Removed the plugs… all dry. Seems to be no gas getting into the cylinders?! When cranking, there is a ‘strong’ suction at the carb intake. Can anybody give me some insight as to what I should be checking?! It’s like the gas is not atomizing?! Can’t figure out how after all that cranking that the cylinders and plugs are bone dry.
Just FYI, I’m definitely no mechanic, but know enough to get me in trouble! lol
Any help will be greatly appreciated.
Mike
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If the plugs are dry, it's an indication that they're firing OK. If you want to know if you have gas to the cylinders, crank it over without the plugs firing, like taking off the coil wire or something, then see if the plugs are wet. If it was me, I'd shoot a little ether in the carb and see if it'll fire.
 
Ok thanks for the tip.
I had it cranking without any plugs in. Just a bunch of 'dust' flying around inside. Probably some old carbon.
Would I have not seen some fuel at that point?
 
I would verify correct firing order, could be 180 degrees out of time, have seen this many times. you can just swap leads across cap without removing distributor if is just 180 degrees off.
 
A couple of ideas. Did you disconnect the gas line at the carb and spin the engine to see if the fuel pump is pumping gas to the carb? If it isn"t, you"ll have to check the lines and filter. I know you said the carb was re-built, but there could be some crud picked up and clogging the jet. Also, check for air leaks at the intake manifold and carb gasket. That might explain the sucking at the carb. Let us know what you find out in the end. Good luck.
 
(quoted from post at 11:48:30 12/28/20) I would verify correct firing order, could be 180 degrees out of time, have seen this many times. you can just swap leads across cap without removing distributor if is just 180 degrees off.

I have verified the firing order for the tractor. It is 1-2-4-3. That was the way I received the tractor and after redoing the points and plugs, I made sure it went back the same way. I didn't touch the distributor at all. Maybe worth taking a look into... If the plugs and cylinders were 'wet' with gas, I could possibly see that but with everything being bone dry, I'm leaning towards a fuel issue. Thanks for the help!!
 
(quoted from post at 16:06:02 12/28/20) A couple of ideas. Did you disconnect the gas line at the carb and spin the engine to see if the fuel pump is pumping gas to the carb? If it isn"t, you"ll have to check the lines and filter. I know you said the carb was re-built, but there could be some crud picked up and clogging the jet. Also, check for air leaks at the intake manifold and carb gasket. That might explain the sucking at the carb. Let us know what you find out in the end. Good luck.

Thanks Super 55!

When I disconnect the gas line, I have to be quick because it sure makes a mess. No flow blockage there. I don't believe there is a fuel pump on this model tho. It comes from the tank, into the strainer bowl, then to an inline filter and finally to the carb. All gravity fed. Maybe some crud got in the carb although the strainer and filter (clear plastic) all look clean. I do occasionally get gas leaking back out the intake but it seems to be random times and only after repeated cranking?!

What I meant by suction at the carb is during cranking, if you place your hand over the the carb inlet, it will suck your hand onto it like a good shopvac. I assumed that indicated no vacuum leaks in the intake manifold. There are no vacuum lines anywhere on the intake system. It seems pretty straight forward in that sense.

It just seems like the gas is not getting from the carb up to the cylinders and I can't figure out why? Maybe the carb wasn't rebuilt correctly. That's the only piece I'm not comfortable playing with as I've never played with one before.

Thanks again for the help!! I'm definitely open to any suggestions :D
 

I don't normally recommend this, but I'd just shoot a little starting fluid in to see if it pops on its own. If it does, then you've narrowed it down to a fuel delivery problem.
 
When you had the carb rebuilt, did you stuff a rag in the intake and forget to take it out when putting it back together? There should be a drain plug on the bottom of the carb, take it out and make sure the gas is getting into the carb. Use a glass jar and let it run for a couple of minutes to make sure you have fuel flow.
 
Hold your hand over the intake on the carb while you're cranking on it. Sometimes the choke just isn't enough, especially if it hasn't been run in a while. Same goes if it's real cold.
 
Have you checked the muffler and exhaust pipe for obstruction possible mice or birds made nest in it Also to check firing at plugs take one out and with a pair of insulated handle pliers hold the plug
with it hooked up to spark plug wire against the motor block and have someone crank the motor over watch for spark. If no spark go back and check points and condenser also possible bad coil with no spark. Joe
 
(quoted from post at 21:13:25 12/28/20)
I don't normally recommend this, but I'd just shoot a little starting fluid in to see if it pops on its own. If it does, then you've narrowed it down to a fuel delivery problem.

It's not my first choice either, but I gave in and bought a can. I'll be back on it this weekend and will try a shot if I still can't get her to start. Thanks!
 
(quoted from post at 07:30:48 12/29/20) When you had the carb rebuilt, did you stuff a rag in the intake and forget to take it out when putting it back together? There should be a drain plug on the bottom of the carb, take it out and make sure the gas is getting into the carb. Use a glass jar and let it run for a couple of minutes to make sure you have fuel flow.

Now THAT sounds just like something I'd have done!! This time however, no rag left in the intake.

I know the gas is getting to the carb because if I crank her over with the choke on full, gas will pour out the intake after 10-15 seconds of cranking. Only seems to do it when the choke is pulled. Doesn't do that without choke. I've read somewhere that with a Zenith 267 carb, not to choke for more than a crank or two or this could result.
 
(quoted from post at 11:09:14 12/29/20) Hold your hand over the intake on the carb while you're cranking on it. Sometimes the choke just isn't enough, especially if it hasn't been run in a while. Same goes if it's real cold.

I did try that previously. That's how I confirmed 'good' suction into the carb. Still no start tho?!
 
(quoted from post at 20:14:22 12/29/20) Have you checked the muffler and exhaust pipe for obstruction possible mice or birds made nest in it Also to check firing at plugs take one out and with a pair of insulated handle pliers hold the plug
with it hooked up to spark plug wire against the motor block and have someone crank the motor over watch for spark. If no spark go back and check points and condenser also possible bad coil with no spark. Joe

I haven't actually done that yet. The exhaust pipe has a rain cap on it, so I just assumed it would be clear. Also, when cranking, the cap just pop up and down with the air pressure. I will take a quick peek on the weekend.

I had all 4 plugs out resting on the loader arm while cranking. They all spark beautifully in the 1-2-4-3 order. I cleaned the points and changed the plugs before firing her the first time so that wouldn't be an issue.

I'm still baffled as to why the cylinders are all dry after cranking. I think I'm going to pull the carb back off and open her up. Have no idea what else is preventing the gas from the carb into the cylinders.

Thanks for the help!!
 
Just curious--did you ever get it started? I am having the same level of frustration with a Super 55 and posted on it earlier today. I would like to hear if there's a success story to encourage me!
 
(quoted from post at 19:23:48 12/30/20) Just curious--did you ever get it started? I am having the same level of frustration with a Super 55 and posted on it earlier today. I would like to hear if there's a success story to encourage me!

No, not yet.
I'm going to try tomorrow with some starting fluid.
I've read your post as well. I'll keep you posted if/when I get her going. I'm not giving up on her that easy!!

Happy New Year!
Mike
 
That was my thought with putting a hand over the carb Chuck. Keep it there until it fires, or better yet, put it in 5th gear and
tow it.
 
Did you get the 550 started? You Stated that you had the carburetor rebuilt. Just wondering if the Venturi was put back in upside down.
 
Hey Guys! Been a little bit since I gave an update. Darn work gets in the way of fun!! lol
So I went back last weekend with some starting fluid to give her another shot. Before I started, I pulled the plugs and rechecked the spark while cranking. Upon closer inspection I noticed that 2 of the plugs would stop sparking after 10-15 seconds of cranking!? Interesting. I actually had another coil in my box of parts, so I switched them. Cranked again and now I have good spark through the firing order for as long as Im cranking. Could it have just been that?!? Still doesnt explain the dry plugs, but Im encouraged at this point. Put all the plugs back and reconnected everything. Went over to the other side and re-installed the carb. Moment of truth. I cranked and cranked and cranked but no dice. At this point my buddy says lets put some gas into the cylinders and try again. Not real comfortable with that but ok. Put a little gas into # 2 & # 4. Put the plugs back and tried again. She did something!! Good size backfire and some smoke out the stack which scared the crap outta me. I tried cranking again and she seemed to want to start but couldnt. At this point we tried with some starter fluid into the carb intake. You can definitely hear the cranking sound change and there was a little smoke coming out the rain cap as she jumped up and down but again, no start. We pulled the plugs back out. Number 2 & 4 had a nice color to them and they had some fuel residue on them as to be expected. Numbers 1 & 3 were shining and clean like I just took them out of the box. Shes not getting fuel for sure.
Ive taken the carb back off and opened her up. Nothing out of the ordinary that I can see. Everything is super clean, no residue. Gasket looks good. Float nice and free. Im stumped at this point. I think Im going to have to find another carb guy to take a peek at it for me.
 
(quoted from post at 15:50:00 12/31/20) Keep choking it till it starts!!

The last time I tried that, gas ended up 'pouring' back out the intake. Like a created a siphon or something. Because she's in a warm garage, I've just been giving her a quick shot of choke and then releasing.
 
(quoted from post at 10:57:09 01/01/21) That was my thought with putting a hand over the carb Chuck. Keep it there until it fires, or better yet, put it in 5th gear and
tow it.

I pulled her back into the garage so she'd be warm. By accident I knocked her into gear and didn't notice. Because of all the snow and ice around here, the wheels just slid. Probably not going to work at this time.
 
(quoted from post at 07:15:15 01/02/21) Did you get the 550 started? You Stated that you had the carburetor rebuilt. Just wondering if the Venturi was put back in upside down.

After taking the carb apart, I can say that the venturi was in its place. Don't think it could be put in upside down as there are 'tabs' on the outer part of the venturi that fit into a spot on the carb body. Upside down wouldn't allow the carb halfs to close back up. Thanks for the suggestion tho!

I'm GOING to get her started. Just not sure how at the moment :)
 
(quoted from post at 12:05:44 01/13/21)

Did you set the float level? How many turns out are your adjustments?

Well I had the carb rebuilt by a 3rd party. Bought the rebuild kit from The Carburetor Doctor.

The carb was soaked & cleaned in an ultrasonic cleaner. The float was sealed and in good shape. No obvious damage anywhere to be seen.

Float level is about 1/4".
From what I was told, the main jet is 3 turns out from a light seat. The idle screw is 1-1/4 turns and the throttle stop is touching plus 1-1/2 turns.

Is there anything else I should be looking at?

Thanks!
 


I don't have a 550 manual in front of me, but those adjustments sound excessive. I won't have access until tonight at the earliest and that's assuming I can find it. Hopefully someone will come along with the right settings.

The last Zenith I rebuilt I set the mixture screw at 1 turn out and the main jet at 2 turns out initially. It was for a Ford 9n though.
 
(quoted from post at 14:17:10 01/13/21)

I don't have a 550 manual in front of me, but those adjustments sound excessive. I won't have access until tonight at the earliest and that's assuming I can find it. Hopefully someone will come along with the right settings.

The last Zenith I rebuilt I set the mixture screw at 1 turn out and the main jet at 2 turns out initially. It was for a Ford 9n though.

I have the manual. Purchased it online.
It doesn't mention the main jet adjustment. The guy that did the rebuild told me that's where it was when he removed it before cleaning, so he put it back the same.
The other settings are listed in the shop manual and he adjusted them accordingly.

No rush, but if you are able to verify those numbers as well, it would be appreciated!

Thanks scootergmc!
 

Sounds good. If it was me, I'd pull the carb and make sure everything is cleaned out, needle is functional, and float level is set at 1 5/32" as indicated on the chart.
 
(quoted from post at 18:06:21 01/14/21)
Sounds good. If it was me, I'd pull the carb and make sure everything is cleaned out, needle is functional, and float level is set at 1 5/32" as indicated on the chart.

So last night, for my first time, I opened up the carb on the bench. Was more straight forward than I thought. I guess you're never too old to start learning! lol

I had mistyped the float level previously without realizing. It is actually 1-1/4" so very close to the 1-5/32".
Everything looked clean. When I took out the main jet adjustment and nozzle, it was actually kind of dirty like it hadn't been cleaned. All orifices were clear, just some dust and debris. To me, the 'leather' washer looks very deteriorated and possibly the source of the dust debris I was finding. The carb kit I ordered doesn't seem to have that washer included. I put it back together for now. I do have another contact that I may send it to for a re-rebuild. Don't know if that leather washer can be purchased or not. If anybody knows of a 'good' carb rebuild kit, I'm all ears. I ordered this kit from the Carburetor Doctor.

Thanks again for the help guys!! I really do appreciate.

Mike
 

Sometimes those main jet parts aren't included in the standard rebuild kits and you order them separately. But the rebuild kits are pretty universal, they include additional parts for other models you won't need, so just replace what's already in there, unless it differs from the schematic I posted. Does the carb have the tag or 5 digit number on it somewhere? If so, just make sure the kit covers that model number.

If you can pull the bowl off, you can do the entire rebuild yourself. Don't be scared. There are plenty of videos on youtube to walk you through.
 
(quoted from post at 11:38:11 01/15/21)
Sometimes those main jet parts aren't included in the standard rebuild kits and you order them separately. But the rebuild kits are pretty universal, they include additional parts for other models you won't need, so just replace what's already in there, unless it differs from the schematic I posted. Does the carb have the tag or 5 digit number on it somewhere? If so, just make sure the kit covers that model number.

If you can pull the bowl off, you can do the entire rebuild yourself. Don't be scared. There are plenty of videos on youtube to walk you through.

The carb number is 14996A. The tag is still on one of the screws. I did get the kit for that model. I believe it was a CK615 kit.
I've seen the main jet adjuster screws for sale but can't seem to find the leather washer or even the washer at the end of the main nozzle tube. I don't believe that washer is even in the carb as we speak. I'll keep looking.
 

Well, know that is a replacement carb, but that shouldn't be a problem. 12427 was the original Zenith carb # on the 550s.
 

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