Glen, Deas, Garlic Pete, etc.

Daron

Hey Daron,

Thanks, Your alright, no matter what Garlic Pete says about you, Oil Slick too. But don't worry, I don't listen to those guys much. That's what I like about you, your always coming up with great pictures and support!!!

I have been working on the d6 here and there changing oils checking swing frames rollers ect. Fixed the winch . Anyways I have not started it for a couple weeks I went to start it today and the pony will not get up and going. It will fire up try to run but wont get up and going then eventually dies out. almost acts like its only hitting on one cylinder. I have checked for spark its giving good hot spark. I have opened the petcocks on each cylinder to make sure they are not flooded they will let gas out but does not seem like there is enoph to flood it. Only wants to run when wide open and at best it may run for about 5 sec and runs like crap. I pulled the carb and checked everything out was not really all that dirty thought maybe the float was the problem but was not. the main issue I found was the gasket going from the carb bowel to the carb body ( where the butterfly's are) was pretty rotted. it fell to peace's as soon as I unbolted the carb bowl. Kind of a different carburetor then im use to working on. Is that how it controls its air to fuel mixture? my book does not say what to set the two adjuster screws to either I almost want to set them at 3 and a half but not sure on this carb. Any idea were I can get the gasket or a rebuild kit? any help would be appreciated thanks guys.

the rebuild kits are out there check the sticky at the top of the bored. some pony share the same crab as the John deer staring motors so that had bean a easy way for some to find it i sure if you do a search it will come up with lost of info. felow acmoc menber Bill campbell i know dose lost of crab rebuilding and sell kits but they might just be for the old gas cat's.

Your CAT dealer should have the carb parts or can get a basic kit from JohnDeere dealers by ordering one for a R, 70, 720 etc tractor pony motor. Also can source stuff from Zenith dealers (search online) www.carbsonly.com . www.zenithfuelsystems.com .

Zenith kit K2067 is a gasket set
AR 13015 is a gasket set from Deere
RE528699 is also a JD gasket set. Not sure if both are still good numbers or what the difference might be

However, your description sounds like a fuel supply problem. Most likely need to start with the tank and clean it and the lines, valves etc all the way to the carb. The carb itself usually benefits from drilling the soft plugs and reaming the rust and varnish from the drilled passages with a drill bit in your fingers. The soft plugs can be replaced by lead shot, shellac coated BBs or I have used beads of soft solder tamped in the holes. This is well worth the trouble to do while the carb is off, it can really make a new engine out of a cantankerous pony.

Initial adjustment after reassembly is to screw needles in gently and then 1 turn open on the high speed mixture needle and 1/2 turn on the idle mix needle. Remember, adjusting the high speed out richens the mix, but turning the idle mix screw out leans the mixture. The idle mix screw actually adjusts an air bleed, so that makes it backward. Tune while running for best performance.

I think ccjersey is right, I think you have a fuel supply problem, or maybe a couple of supply problems.

You mention that it will start and run at high idle for 5 seconds or so, then drops off. Many times this symptom indicates a plugged fuel tank vent. Without a vent, the carburetor bowl can fill over time, the engine will start, but as soon as fuel starts flowing, a vacuum is created in the tank, with just a little dribble able to supply the carburetor. This is often just enough to keep the pony running on one cylinder, or slowly on both if the choke is kept closed.

A couple of weekends ago I decided to fix one of our 9Us, which needed full choke to keep running. I thought it was the bottom passage of the carburetor bowl being plugged, which is the most common problem with these. This one turned out to be the gasket in the sediment bowl having swelled and nearly plugged the outlet from the tank into the sediment bowl. Same symptom as you describe, would start and run good momentarily, then settle down to no power, needing full choke.

Best test for either is open the fuel line as close to the carburetor as possible and make sure you get a good healthy stream of fuel for ten or fifteen seconds, at least. If the stream is weak, or starts strong but decreases, start working your way upstream to find out why.

If the stream stays strong, your problem is probably in the carburetor. That cross passage through the bottom of the bowl casting is the most notorious. It always accumulates little bits of dust and varnish from the fuel which lays in there even if you run the pony dry. As ccjersey said, drill out the soft plugs at either end and gently ream the passage with an appropriate size drill bit. You'll probably be surprised the gummy junk you'll get out of there, even if the bowl looked clean.

If you do get anything out of that passage, you can probably put the carburetor back together and I'll bet it'll run like new.

Good luck,

Pete.

well I finally got some time to do some more work to the old girl. After cleaning out the swing frames I noticed that every top roller stand on both swing frames was wobbling around. So out came the cutting torches. Had two stands that were missing two bolts and one stand that still had them all. The bolts that were left had been loose for so long they were bent and stuck took a lot of heat and back and forth action to get them out. Now that the stands are out of the way will have to spend some time with a drill bit and easy out trying to get the remaining broken bolts out inless anyone on here has a trick way of doing it . Also noticed after cleaning the one swing frame that the screw adjuster that keeps the track tight was broke off right at the idler so had to dig the broken shaft out of the idler yoke. that was a big pain!!!!! got it all lined up and with a little more prep work will hopefully have it welded later this week. After this is all done will be working on striating the one sweep that is bent to heck should prove to be Fun Hope everyone had a good weekend here is a few pics of progress.

A broken adjuster is caused by worn hooks on the inside of the track frame below the idler bearings.
Wear here means the adjuster is trying to stop the idler moving up and down. some thing it is not designed to do.
Also there are replaceable wear strips in side the fork on the track frame. the adjuster is the same on a D7 4T 3T 7M
Hope this helps.
Andrew K.....

The D7/9U adjusters are not the same part numbers in my parts books. Better check again. They look alike but the 7's are up sized.

Old Magnet
Do you happen to have a book that gives you the toque specs on the roller stand bolts? Also My book does not give me the procedure on getting the idler tracking strait either was hoping you had something on that as well think I should get it as strait as possible before I weld it up someone has run it a long long time with the track adjuster broke so the idler is really warn on one side not sure if I can weld that side back up or not?
Thanks Robbie