Hi everyone,

I have been going over my recently acquired D4 5T 1702. It starts well now on the pony after I drilled the plugs out of the carb and cleaned all the passages. Also checked out the mag and found the difference between barely getting it to pop and running nicely is .010 gap in the points vs .020 as recommended.

Here are a few things I noticed:

The pony clutch drive oil smells like gasoline diluted pony oil. When I pulled the level plug, a gush of this oil came out. I put the plug back and have left it for now. Havent looked into this, but I presume oil can migrate from the pony crankcase to the drive clutch?

The oil reservoir for the injection pump contained a small quantity of what appeared to be very diesel diluted engine oil. I drained and replaced with 10w30 diesel eng oil. There was also some shrapnel in there. See pic.

I cleaned and changed oil in both oil bath filters. The main was about 1.5" of settled silt. It was super hard packed but I scraped it out then solvent tank then heated pressure washer on the bowl and elements.

There is a ton of heavy rust scale in the rad. Was thinking of running it up to temp with a good amount of rad flush.

The pony starts on one or two pulls if it is cold. I pull the choke and maybe half throttle and it fires right up. If I try to start it after I've been running the main and it is operating temp, it is a dog. It seems to be very finicky and it seems to be flooding but then still a bear after shut off fuel, open cylinder petcocks and vent out. Pulling plugs, brakeclean, it still fights sometimes taking 20 pulls.

Any pointers are greatly appreciated. I'm pretty new to these old girls but quite enjoying the learning.

"Mangoman" wrote:

Hi everyone,

I have been going over my recently acquired D4 5T 1702. It starts well now on the pony after I drilled the plugs out of the carb and cleaned all the passages. Also checked out the mag and found the difference between barely getting it to pop and running nicely is .010 gap in the points vs .020 as recommended.

Here are a few things I noticed:

The pony clutch drive oil smells like gasoline diluted pony oil. When I pulled the level plug, a gush of this oil came out. I put the plug back and have left it for now. Havent looked into this, but I presume oil can migrate from the pony crankcase to the drive clutch?

The oil reservoir for the injection pump contained a small quantity of what appeared to be very diesel diluted engine oil. I drained and replaced with 10w30 diesel eng oil. There was also some shrapnel in there. See pic.

I cleaned and changed oil in both oil bath filters. The main was about 1.5" of settled silt. It was super hard packed but I scraped it out then solvent tank then heated pressure washer on the bowl and elements.

There is a ton of heavy rust scale in the rad. Was thinking of running it up to temp with a good amount of rad flush.

The pony starts on one or two pulls if it is cold. I pull the choke and maybe half throttle and it fires right up. If I try to start it after I've been running the main and it is operating temp, it is a dog. It seems to be very finicky and it seems to be flooding but then still a bear after shut off fuel, open cylinder petcocks and vent out. Pulling plugs, brakeclean, it still fights sometimes taking 20 pulls.

Any pointers are greatly appreciated. I'm pretty new to these old girls but quite enjoying the learning.

Hi Nathan
Sounds like you're getting things sorted out. I would dump the clutch oil and refill with fresh. Run it a few times and see if it stays good or gets contaminated again, no telling how long its been in there.
If you're getting diesel in the injection pump oil check your drain lines are not blocked. If they're open there's a couple of orings in the fuel tower that could need replacement. Not a huge job to do.
I'd be careful about being to aggressive with the cooling system flush, you might clean it to good and develop leaks somewhere else.
I haven't mastered the pony motor carbs yet but a little adjustment on the fuel mixture might help.
My 5t is 1600 so pretty close manufacture date. Looks like your tracks are in a little better shape than mine

Starting easy when cold,but harder when warm is a sign of weak electrical. Not my area of expertise (not that I have one) but coil or condenser are the most likely weak places. This day of questionable new electrical parts for the older stuff,hopefully a better adviser will comment. Many stores about putting in new from China parts in and going from poor start to no start until the old parts are reinstalled.






So easy to forget to give the old yellow iron the love it deserves. Very guilty of that myself. Getting hard to climb up and down,keep telling myself next time I go to use it.


Great that you are including your kids in the process. I my option a big plus from the virus is parents just being with the kids. I was allowed to copilot on a RD6 with that big seat a lot.

"d2gary" wrote:

Hi Nathan
Sounds like you're getting things sorted out. I would dump the clutch oil and refill with fresh. Run it a few times and see if it stays good or gets contaminated again, no telling how long its been in there.
If you're getting diesel in the injection pump oil check your drain lines are not blocked. If they're open there's a couple of orings in the fuel tower that could need replacement. Not a huge job to do.
I'd be careful about being to aggressive with the cooling system flush, you might clean it to good and develop leaks somewhere else.
I haven't mastered the pony motor carbs yet but a little adjustment on the fuel mixture might help.
My 5t is 1600 so pretty close manufacture date. Looks like your tracks are in a little better shape than mine

Hi Scott,

All good points. Maybe I will just keep a holding pattern while I'm ahead with the cooling system. I flushed the rad in an old car and then that was it for the rad. Maybe a mild flush as it is pretty bad but wont get too crazy with it.

And yes who knows the these components could have not been touched for 50 years. I will change oil and monitor.

Yes maybe rich? It runs very nice after it goes and pulls the main on compression with no hesitation whatsoever. Maybe the main is worn out 😮 Nah I think it's ok but it only takes part throttle to run it up to governed rpm so that's good I think. Not the case with my 7U. It labours hard to get there.

I think my links measure around just over 3.25" so that's past 100% worn and bushings worn through one side but it still goes forward and back so that's good for now.

Will have to get down there once things chill out and check out your old iron. Learn a thing or two about a thing or two 😁👍

"Ray54" wrote:

Starting easy when cold,but harder when warm is a sign of weak electrical. Not my area of expertise (not that I have one) but coil or condenser are the most likely weak places. This day of questionable new electrical parts for the older stuff,hopefully a better adviser will comment. Many stores about putting in new from China parts in and going from poor start to no start until the old parts are reinstalled.

So easy to forget to give the old yellow iron the love it deserves. Very guilty of that myself. Getting hard to climb up and down,keep telling myself next time I go to use it.


Great that you are including your kids in the process. I my option a big plus from the virus is parents just being with the kids. I was allowed to copilot on a RD6 with that big seat a lot.

Yes I'm not too sure how to check those components but may be worth a look for sure. Its unfortunate "new" China parts are so dodgy. Everything these days hey? All about $$, no pride in a long lasting product. That doesnt make as much $$.

Yes when i was a little guy, my Dad would drag me around and i got lots of exposure to iron. For him it was work but for me it is recreation. The kids seem pretty keen so I'm happy to indulge. We get lots of family time as I'm 7-3 M to F and my wife is part time so that's pretty good. Oj the topic of kids riding on tractors, I think a D8 with that big wide seat would work nice 😁 Too bad we dont even have a full acre 😂

Hi Team,
depending which brand magneto you have fitted the points gap varies.

Am Bosch uses 0.014" to 0.018"--try for 0.016"

Eisemann uses the 0.020" you mention.

As a further tune up internally both magneto's can have their "edge gaps" adjusted for a hotter spark--this also can be affected by miss adjusting the points gap.

Metal core spark plug wires are the only ones to use for magneto's along with non-resister plugs and wire end caps etc.

Be aware that some new spark plugs although not marked with the usual R to signify Resistance type can have resisters in them, even the traditional plug letter/number symbol marked non-resister spark plugs--sneaky mongrels--with a Multi meter set to Ohms, measure the resistance of the center electrode from the outside wire cap to the tip at the firing end and see what you have-- should be zero--also check your leads for same.

For older magneto spark systems I like to reduce the spark plug gap to around 0.015" to 0.018" for easing the loading on the old windings etc.

For poor sparking magneto's that run OK when at speed I have used a lead pencil to put a coating of graphite powder on the plug electrodes by rubbing it on to both electrodes to powder some graphite there to achieve an easier start--the graphite powder flashes bright sparks -- but is gone after 3 or 4 sparks.
It is normally enough to get a start.

Your experience may vary.
Cheers,
Eddie B.

I do have the Eisman mag. It was at .010" and when I set it to the. 020" spec it fired right up. Plugs are new NGK set at .020". I cant remember the number but I did get the number from here and it is the non resistor type. I have struck out on solid core wire locally but will track some down on ebay or somewhere else. Thank you all. Eddie I wish humans had USB ports. I would like to download as much as my head could handle. In any case, one bite or byte at a time. Also, where does one even go about finding mag parts?

The wires on it now are solid core. They are just as old as the hills and one is fairly tattered. Will definately replace here once I find where to get the proper stuff.

"Mangoman" wrote:

I do have the Eisman mag. It was at .010" and when I set it to the. 020" spec it fired right up. Plugs are new NGK set at .020". I cant remember the number but I did get the number from here and it is the non resistor type. I have struck out on solid core wire locally but will track some down on ebay or somewhere else. Thank you all. Eddie I wish humans had USB ports. I would like to download as much as my head could handle. In any case, one bite or byte at a time. Also, where does one even go about finding mag parts?

Nathan I have an Eiseman mag that you're welcome to for postage. I don't know anything about it but it's complete minus the gear. You can't have to many spare parts