1650 rehab thread

[The Dark Side of Will]

I have a CC 1650.
My dad snagged it from his neighbor across the street.

I bought a place with 1.2 acres (~1/3 wooded) and had him bring it up to me. It didn't run well, but drove itself into the shed.

I tried to drive it out of the shed but it wouldn't start. I found it had no spark. I rebuilt the ignition system using a Kirk Engines Transdenser II. The external wire Kirk provided just won't work, but a CarQuest STP483 3/16" female spade terminal reterminated the original coil ground wire to work with the Transdenser.

Transdenser: https://www.kirkengines.com/index.php#1

The original coil was oozing boiling goo from some cracks in the cap. The Transdenser requires a coil primary resistance in the 3-6 ohm range. I replaced the original coil with a Pertronix Flame Thrower epoxy filled coil from Summit Racing. It's one of the few canister coils I found with a 3.0 ohm primary winding. There were some coils with 5 ohm primary resistance, but they were all for motorcycles. The only canister coil I found with 5 ohm primary resistance is a "dual fire" unit with two outputs for a dual plug Harley. Funky.

The coil I bought: https://www.summitracing.com/parts/pnx-40611

The Pertronix coil is *slightly* larger than the original coil, so I had to replace the original 10-32 x 1.5" coil clamp screw with a 10-32 by 1.75" screw. Other than that, everything went right together.

The Transdenser sinks coil drive current to ground through its case, then through the original condenser clamp into which it mounts. That connection has to remain low resistance despite exposure to weather, so I installed the Transdenser with "bulb grease" in the joint.

I also replaced the plug and have a new coil wire on the way. I did *NOT* waste $60+ on a OE plug wire. Standard Motor Products 812CA or equivalent *should* work just fine. I have one on the way, but haven't tried it yet since the tractor still runs on the original wire.

I also have replacement engine mount bushings, but have not installed those yet.
After some trial and error, I found that a CarQuest L481 1/2" x 81" belt works for the deck, although the spring tensioner is *slightly* inside where the marks say it should be.
I also bought a new muffler from CC, as mine has cracks around the connection to the engine.

Now, the engine runs passably, though not great, at idle, but is really ragged at WOT. It misses a LOT, has little power and doesn't sound like it's attaining 3000+ RPM. It starts readily cold but will NOT restart hot.
The service manual says to turn the open throttle mixture screw in to lean it, and do the same with the idle screw, remaining aware of some interplay between the two. I have not done that yet, but will be soon.

The Transdenser instructions mention setting point timing using "P & SP" marks on the flywheel. I used the sight hole on the side of the engine to look and stepped the flywheel all the way around with a screw driver on the ring gear teeth, but never saw P or SP. I saw ONE horizontal line, but did not verify it had any relationship to TDC.

What mark on the flywheel should I actually be looking for to set point timing?

Is there a trick to replacing the engine mount bushings? They look like a PITA. I assume it's wise to drop the deck to make that job easier.

[ol'George]

First,
welcome to OCC
Take that kirker/jerker lectronic bullshit thingy off and put it in the trash.
Clean the points that have been on there for 40 years and they will be good for another 40 years.
You can replace the condenser if it is suspected bad.
When bad they will idle, but not rev up.(they are inexpensive)

Down load the service manual from kohler,
available free here on OCC.

The timing marks are there I guarantee, just not easily seen.
Use a bright light and look when the piston is near TDC.
There will be 2 marks, one before TDC and one on TDC.
Search "static timing method" here on OCC and follow it,--it is simple and fool proof.
Then set the carb to factory settings initally.
Idle air first, then high speed mixture.
After that adjust to fine tune, error to richer on main jet not leaner.

As far as motor mounts:
Remove deck & mule drive.
Then remove engine as it is strongly suggested to modify the cradle that mounts engine to frame, after all these years they are usually beat pretty bad,
Chances are you are going to find stripped motor to cradle bolt holes in the aluminum oil pan.
That has to be addressed,either repair the threads/resurface or replace the pan with a cast iron one from various sources
Again,search "cradle mod" on here.
That should keep you busy for a while.

[AndrewNoyes]

If you read and try the static timing document George linked, you can find out where the points are opening currently. It would seem that the line(s) you are looking for should be in that area. It should help narrow the search a bit. Also, i read that people have used an ink eraser (you know, the kind with a little abrasive in them) to rub off the rust and see the letters a little easier.
Good luck!
Andy

[cooperino]

What Ol'George said.

For some of the reasons he said and others. My reason. If any of that system fails you are SOL maybe in the middle of cutting grass.. Points are super simple and you can just about always get em going even when quite worn out. Points are available at most parts stores. This is the same reason they were used in boats forever. They rarely keep you from running for more than a few minutes if you know how to adjust and clean them.

[J-Mech]

The points are still installed, and used, with the "Transdenser".

George hit the nail on the head...with EVERYTHING he said. Take his advice. Take it off and toss it in the garbage. Then do all the other stuff.

[twoton]

I must be missing something here?

Still can't figure out what the heck is a Transgender Cub Cadet?

Edit: Oops, my bad. Transdenser. Ok, got it now.

[The Dark Side of Will]

Originally Posted by ol'George

First,
welcome to OCC
Take that kirker/jerker lectronic bullshit thingy off and put it in the trash.
Clean the points that have been on there for 40 years and they will be good for another 40 years.

I'll take it under advisement.
My prior experience with converting small engines to electronic ignition includes a Tecumseh that was a SOB to start. I always took multiple priming cycles and several pulls. I replaced the original system with an electronic ignition utilizing the original flying magnet trigger. It started, first pull, EVERY TIME.
I have similar experience converting cars to EFI... Electronics are ALWAYS more reliable.
The reason the points only last 40 years with the original ignition is that they have to pass >2 Amps of coil current. The electronic ignition is nothing but a solid state relay that reduces coil current to ~50 mA. Points will absolutely last forever with that current. Done.

If there were an EFI kit for these engines, I'd probably buy it.

Originally Posted by ol'George

Down load the service manual from kohler,
available free here on OCC.

From here: http://www.kohlerengines.com/engines...df/tp_2379.pdf

Downloaded. Will review

Originally Posted by ol'George

The timing marks are there I guarantee, just not easily seen.
Use a bright light and look when the piston is near TDC.
There will be 2 marks, one before TDC and one on TDC.
Search "static timing method" here on OCC and follow it,--it is simple and fool proof.

I'll review the manual and have another look.

Originally Posted by ol'George

Then set the carb to factory settings initally.
Idle air first, then high speed mixture.
After that adjust to fine tune, error to richer on main jet not leaner.

I played with the mixture screws today. The previous owner may have been tuning it to start in winter in order to use the snow plow. I leaned each mixture screw a full turn and it's much more tractable now, thought still not where it should be. I have not yet undertaken a factory mixture setting procedure, but will.

Originally Posted by ol'George

As far as motor mounts:
Remove deck & mule drive.
Then remove engine as it is strongly suggested to modify the cradle that mounts engine to frame, after all these years they are usually beat pretty bad,
Chances are you are going to find stripped motor to cradle bolt holes in the aluminum oil pan.
That has to be addressed,either repair the threads/resurface or replace the pan with a cast iron one from various sources
Again,search "cradle mod" on here.
That should keep you busy for a while.

That's going to be fun. I've helicoiled plenty of parts to date. :-/
I can see the engine dancing around on the "cradle" plates. Yes, it will need a day of work to be right again. Sigh.

[J-Mech]

You need points to last longer than 40 years?

We all know what the Kirk "transdenser" does, we don't need a lesson, but thanks. Some on here have used them, several have had issues while using them. Those of us who have "been around" and know how to time and tune these engines agree they are a waste of $40 (or whatever they cost now). Believe us, me, George and others when we say they aren't worth it. It isn't an electric ignition conversion. It doesn't replace the points with a PIP sensor, it just lowers the amperage to the points and allows you to run a slightly hotter coil, but only by maybe an OHM or two. Hardly worth the trouble.

On tuning carbs... yeah, we've done a lot of that too. Don't use the "factory" setting. If you read the manual exactly, it clearly states the recommended setting to be used as a starting point to tune. You can't really read in a book how to tune a carb. It's more of an understanding of the engines reaction to the setting. As George said, you need to err on the side of rich. It's far more likely the PO just didn't know how to tune it, than it is that he had it set for winter. I seldom change my carb settings in the winter months. And we have temp swings between summer and winter of up to 115°. Do read the manual on carb tuning, it does a pretty good job of explaining it. Start by setting the idle stop screw to just contact the throttle plate stop. Adjust the low idle mix screw and the idle stop screw in increments together to obrain the low idle mix. A K341 has a good idle spot where it runs pretty smooth. Find it. It will not be at the speed the book suggests.

You will need a tachometer of some kind to set the high idle, no load speed. Then, adjust main fuel after that speed is obtained. Double check both low and high idle speeds and settings when done. Tweeking will be required.

Once you throw away the Transdenser, get a good condenser, set the timing and tune the carb, it should fire in no more than two revolutions. More if it's really cold out.... maybe 4 or 5 revolutions.

If you want electronic ignition and EFI, Kohler does offer those in their new engines.

You are welcome to read the Kohler manual on static timing. Or you can use this:
https://www.onlycubcadets.net/forum/...ad.php?t=33461

[ol'George]

Originally Posted by The Dark Side of Will

I'll take it under advisement.
My prior experience with converting small engines to electronic ignition includes a Tecumseh that was a SOB to start. I always took multiple priming cycles and several pulls. I replaced the original system with an electronic ignition utilizing the original flying magnet trigger. It started, first pull, EVERY TIME.
I have similar experience converting cars to EFI... Electronics are ALWAYS more reliable.
The reason the points only last 40 years with the original ignition is that they have to pass >2 Amps of coil current. The electronic ignition is nothing but a solid state relay that reduces coil current to ~50 mA. Points will absolutely last forever with that current. Done.

If there were an EFI kit for these engines, I'd probably buy it.




From here: http://www.kohlerengines.com/engines...df/tp_2379.pdf

Downloaded. Will review



I'll review the manual and have another look.



I played with the mixture screws today. The previous owner may have been tuning it to start in winter in order to use the snow plow. I leaned each mixture screw a full turn and it's much more tractable now, thought still not where it should be. I have not yet undertaken a factory mixture setting procedure, but will.



That's going to be fun. I've helicoiled plenty of parts to date. :-/
I can see the engine dancing around on the "cradle" plates. Yes, it will need a day of work to be right again. Sigh.

Do as you please as far as far as the 'lectronic trigger,if 40 some years is not considered a long time, have at it son.
I have engines running here that were made in the mid 50's and never had the points changed.
Oldest running engine I have around here is a 1915 Continental that came out of a Saxon model B roadster
Your money your tractor.
Different strokes, different folks.
These old engines sure as hell don't need EFI.
We would still be using carbs, except the epa rules ran them out of town.
Ain't nuttin simpler than the venturi principal in a carb.
These old flatheads are only running 6 1/2 to 1 compression on a good day.
As far as helicoil, it's a good repair if done right and you put the pan on a mill so all surfaces are flat, true and parallel.
'course the first time you remove the bolts, out comes the helicoil.
When you are all done a $35-45 dollar cast iron pan on evilpay is a good deal.
That pan takes a hell of a lot of vibration from a single piston the size of a SBC chevvy pounding up/down.
I know a heli is posta be stronger than a thread, but real world isn't as rosy a picture.
Timeserts are better @ staying put, or go to 7/16-20
As far as a tejunkski 'injin, yep them magneto's need spun a little faster to produce spark.
Those newer flywheel 'electronic triggers are nice when they are working, but that is the key word, "working"
Now when the points are buried under the flywheel, triggers are a nicer deal,
Till you have to replace them, then shell out big $$$$$$
A little ribbon of crocus cloth goes a long way removing oxidation on points.
Have fun and, welcome to the madness.

[The Dark Side of Will]

Originally Posted by ol'George

..lectronic bullshit thingy off and put it in the trash.

Sooo... there's a bunch of baggage on both sides of this.

I've heard plenty of things like the above from the classic hot rodding crowd. They usually tell me I should rip that electronic stuff off and use a carb because I can fix it with a screw driver. I prefer fuel injection that doesn't break in the first place.

I've built enough space flight hardware to know that electronics are far more reliable than mechanical devices (well... as long as current and heat limitations are met). That doesn't mean that the Transdenser is a great product, as a worthy electronics engineer is unlikely to be moonlighting making ignition relays for 40 year old lawn tractors.

Or maybe it could be a great product that was used outside of specification.

Even in the fuel injection world (especially in the classic BMW community) I've run across plenty of people who have a problem and throw parts at it until it goes away. Then they blame the last part they threw at it instead of their terrible diagnostic skills.

Can anybody link examples of failures in a Transdenser module?

Do I need to clean the points? Sure. I did the factory mixture procedure and as I was about to test that, I noticed that the indicator light in the Transdenser was flickering. Since it's not supposed to do that, I checked things further. I can rotate the engine and the light will get bright, then dim and flickering. This doesn't mean there's a problem with it... just that the points are still passing enough current to light the LED when they're supposed to be open. That means I should clean and retime.

In the process of playing with it, I found the location at which the points open as indicated by the LED and a VERY healthy spark. I checked the timing window and, lo and behold, there was the single timing mark I mentioned earlier.

Cliff's Notes: Next up: cleaning the points.