Recent content by Auto Doc's

Thanks V., Star Tech sent me a link to the same. I've been looking it over while waiting for the head kits to arrive.

Hello C, The tool you described is often referred to as a vibration/frequency tachometer by some folks like me. I've had mine for 40+ years. I never can recall the German name of it. It is a simple device that works very well for reading the RPM on small engines...

Everyone wants to create confusion these days. It's all about the money and who can claim ownership.

Sad to say, a "Barn find" usually means a badly broken-down machine that needs lots of work or it is a parts machine. These are not a "miracle restoration" find most of the time unless you want to spend money on them.

Hopefully the coils have not been overheated by the excessive gap for too long.

Recheck your battery installation and clean the cable ends a battery posts. New batteries often have a gray oxidation on the posts.

Also, don't neglect the oil filter. It is worth the money when changing the oil.

Hello C., These engines run at a fixed high RPM of about 3400 RPM as I recall. They do not have a throttle cable to regulate the engine speed like the older mowers did. You might try hitting the primer bulb just once when hot to see if that helps. Otherwise, the primer bulb and the air...

Hello Newbie Jules, We need the product label information off of the chassis of the mower.

Hello M., Welcome to the forum newbie. Anytime you need help with your equipment, we need the chassis product identification label information. If a problem involves the engine, we will need the engine product label information also. Otherwise, we are just guessing and that could easily...

Do you own a test light and a multimeter? Some engine and chassis numbers would be a big help because crystal ball is not as reliable these days.

Hello Folks, Keeping equipment "at the ready" is something I had instilled in me year ago. I grew up in the mountains of Virginia and recall when we would drain or siphon/pump all the fuel out of equipment for our cars and trucks then run the equipment carburetors dry and store them for the...

A 5-gallon bucket with a few grains of cattle feed works nicely. The cat knows right where to find them after a couple of times of getting them out.

WAG The vacuum pulse pump is not working properly, or a fuel supply line is collapsed or blocked internally. Fuel lines typically fail from the inside.

Hi Star Tech, Sticky intake valves in the guides? Similar problem like the Kohler twin I'm dealing with right now? Just a thought.

Hi Star Tech, We had a "Blue Northern" 20-degree temperature drop in the past 24 hours. We went from the mid 90's to the 70's in the daytime and upper 40's at night. We don't get many slow seasonal weather transitions here in South Texas. Thanks for the bulletin. The #2 head kit came in late...

Hello H., Yep, once I added up all the separate parts prices (and shipping), it made more sense to go with the head kits Everyone seems to think every little part is gold these days. Of course, a complete replacement engine is not cheap either.

That is the deck drive belt hanger that attaches underside just behind the main engine drive pulley. These are used on lever type PTO operated deck drives and prevents the belt from jumping off when the deck is disengaged. Looking at the worn hole, it has been loose for a while.

I cannot believe I am reading some of this stuff. This has "ethnic engineered" written all over it. Determined to make it work no matter what? What's next? A piece of tin, some self-tap and more RTV to cure for a few days? Any new gasket, or just resealing what's there?

Hello J., Mix up some Acetone and transmission fluid (50/50) and wet it down lightly for a couple of days. Keep the mixture in a jar with a tight lid if you can. Then try loosening the square head bolts, first, carefully. Once you can get them removed, put a few drops of the mixture in the...

Hello C., First problem I would look for is the upper-case bolts under the edge of the flywheel are backing out. They will rub against the flywheel and also crack the engine block in the front if they are not caught in time. The engine factory failed to put Loctite on them during engine assembly.

Thanks Star Tech, I have a fairly good library, but every now and then I get a unit in that I just don't have the needed specs for.

Hello H., Valve springs collapsed, rocker studs backing out and both intake valves very badly stuck in guides due to suspected bad/contaminated fuel being used. The part numbers for the heads have had 3 different revisions. I figured that I am better off going with the Rehlko/Kohler head kits...

Go to link, use left drop down on page for wiring schematic, click on that to open then expand the schematic so you can see how the wiring circuits connect. Hopefully you are not using Amazon generic switches...

I have a Kohler PT-KT735-3077 engine that I am getting ready to put a set of new factory heads on and would like the most current engine repair information if anyone has it in the library or links available. I've check mine and do not have it. The heads will not likely be here until next week...

Time to start looking for an older core engine for the cam. I have had to do that a couple of times for different model engines. Plastic cam designs are just another factory engineered failure point that people do not expect. The industry is trying to do away with small engines, especially on...

I agree GearHead36, Most are built these days to barely make it 5 yr. with even good service. The "Green Power" lobbyists are trying their best to abolish gas- and diesel-powered equipment as fast as they can. Apparently, they are ignoring where all the high-tech battery waste is going to go...

Look it up by the information on the engine label and see if there is a replacement steel cam offered.

Hello rs334, We need the information off of the valve cover or stamped into the metal fan shroud. Some engine had the numbers etched into the flat side of the engine case on the opposite side from the carburetor. There were many of these engines built with these basic dimensions but customized...

Hello H., I only consider auction equipment for needed hard to find parts most of the time. Most of the stuff that no longer runs ends up at an auction usually because they have major non-running issues. Ive only been lucky a couple of times on some of the ones that looked like they had...

Coil kill wire diode gone/going bad? Unplug the coil ground lead to see if problem still exist.

Hello Newbie Hawk Eye, Whenever you need help with an equipment problem, please provide the product label off of the chassis and the engine. The equipment manufacturer does not build the engines for their equipment. The more information you can provide, the more accurate answers we can provide...

Hello B., The only warranty I would advise on used equipment is to have a buyer thoroughly test run and cut with the machine while I am present to confirm everything is in good working order. Once it leaves my place the "warranty period" is over. I have an area designated for "test runs and...

How much will anything sell for? It depends on how much the buyer wants it and is willing to pay at the time. Cash is what most sellers want, not financing headaches. The one problem I see much of the time is people think a credit card or a bank check is the instant solution to spontaneous...

hello C., Go to the Champion generator website and look for their load wattage calculator. It is a fairly generic list of items that are common with most households. https://www.championpowerequipment.com/generator-wattage-chart/ I usually find out the running wattage of an item (on a label...

I slomo, Back when I was a kid (60's70's) helping out on used cars and trucks, we would hold the idle up high on and engine and trickle a little water at a time in the carburetor throat to detonate the carbon on the cylinder heads, pistons and valves. It was amazing how well an engine would run...

Have you ever made pudding and found out the milk was sour? Looks good, but the taste tells another story. LOL

Hi StarTech, It never fails... Late in the evening and running empty on 20A fuses.... and the parts stores are closed. LOL (Parts stores think that fuses are gold anyway) $12.99+ tax at AutoZone for a 10 pack (if they have them). I quit buying bulk box sets of fuses online because many of them...

In engineering terms, it is known has "predetermined failure rate" and "material longevity rate". Both a very real. There are volumes of material studies that address every material characteristic known to mankind.

Look around the chassis carefully, because they often attach one to the metal floor area or engine base. Does that regulator have the typical 3 wires and then 2 more in the middle of the epoxy? I know some Kawasaki and Kohler engine had that style. On the B&S, the charge light circuit is likely...

Before you waste a trip... Do you have a multimeter? If so, an Ohm test will confirm a diode easily. One direction of connection show continuity, switch the meter leads and it should show no continuity. Diodes are a 1-way electrical door. If it tests continuity in both directions, the diode is...

Loosen clean and retighten all of the harness grounds starting at the battery.

We need the product ID label information off of the rear chassis of the unit to determine if it is an early or later production model. John Deere made a lot of changes during production, so the year model does not tell up much.

At the moment, I have a young man (senior in High School) who claims he wants to "learn small engine repair". It gets better... Normally I just call him to pick up the parted-out cores and chassis I have sitting around, but he called me one day and said he wanted to bring a mower over for me...

I recommend you study what tensions the deck belt. Does the whole deck shift back and forth to tension the belt? I'm not familiar with any that do that, but engineers can be creative.

Hello G., It's all a product of easy credit and low interest rates. I hope they (financial institutions) wise up and raise interest rates even more on credit cards and put a cap on borrowing. Quit letting companies file for bankruptcies, then restructure and do the same thing all over again.

Hello hlw49, All the craze right now seems to be battery operated "Green environment" equipment. Unfortunately, many of them are starting to break down and there is no repairing them economically. So, what do they do? They just go buy another one. They are just piling up, and no one cares...

That spring apparently has to do with the blade brake release mechanism that is on the pulley. Without the machine running, try to engage the deck lever and see if the brake moves away from the blade/ belt drive pulley.

If it has a blade, it is a "brush cutter", if it has string it is a wheeled weed eater in my opinion. A 137cc engine does not have the power to cut very big stuff. What engine is on this machine? Is it a Briggs and Stratton with the black plastic carburetor? From your description it sounds...

I have had Ohm tests lead me down a wrong path many times, so no I prefer using a device called a Load Pro or a Halogen headlamp bulb to confirm a wire can actually carry a load sufficiently. A basic Power Probe and a/or a test light can also give false positive results.

Hi Slomo, You know this, but I am sharing this with the masses who don't. I have seen a lot of people who coin the phrase "parasitic draw" lately but have no idea what it is or how to test for it using a DVOM. Most just break out the credit card and start buying up the parts online until they...

Flea market and backyard sellers along with auctions seldom let you really check out a machine before purchase. If they avoid letting me give it a good test run evaluation, so I walk away. Too many people are referencing the internet and think they can demand at least 50% of new retail prices...

Man, that is a lot of plastic and money for an HD drill motor with a blade. The last couple I have dealt with broke the motor field magnets and locked solid just out of the warranty period.

My crystal ball says seat switch or too light of an operator in the seat. Hard to really diagnose from this distance without the chassis identification label information and my pet AI troubleshooter choked to death last week

If it is an electric PTO model, check the PTO clutch for a worn-out bearing. It will wobble around wildly when you check it from the very bottom of the bottom plate if the bearing is bad.

Remove the right console cover and locate the plug-in "box diode". Remove it and see if it all works them. The seat switch is also common to wear the harness and short to the seat frame.

Judging from your description the swash plates have worn grooves into them, and it is bypassing fluid which creates the whining. Next possibility is the sump screen on the bottom inside is choked up and creating a fluid blockage. You would have to contact Tuff Torque and see if they still sell...

Hello J., It helps us greatly if you provide the chassis product label information along with the engine label information. The rider manufacturer does not make the engines they install on their equipment Have you had the battery tested? Do you own a multimeter? Before you hit speed dial...

Hello P., Please provide the product ID label information that is attached to the chassis. It is usually under the seat frame or the area below the seat. Cub Cadet made constant changes to their designs through the years. WAG method would be to test the seat switch.

Those are the headaches a person deals with when swapping most engines. They are a different build spec according to how each rider chassis manufacturer wanted them to appear "custom". Sounds like you are making decent progress though. Be glad you double the parts to mix and match what you...

I would say they are close. One is a '97 and the other is a '99 according to the first two digits in the code information. Both are 16HP V-twin design according to my quick online search. and will bolt up because they have an industry standard bolt pattern. The difference come with the wiring...

If it will run for at least a few seconds. it is likely a fuel issue such a coated over in-tank screen or inline filter. Today's cheap Ethanol pump fuels I am finding are often contaminated or reclaimed bad fuel passed off as good to a mom-and-pop store just trying to stay in business...

Hello V., I drove out one of the intake valves with a hammer and long punch to get a better look at the valve stem. The first impression I had of the coating on the stem and part of the intake port reminds me of hard candy. It was not the typical crispy cooked carbon like I was expecting. The...

With a compression release it should build up to at least 65 psi after a few pull/cranks. I suggest you remove the plug and the valve cover and watch the valve movement while cranking over. The intake valve will likely not open the same amount due to a worn-down cam lobe.

Hello sgkent, I've never tried a "cold" solvent experiment like that, but it sounds interesting. Most solvents that used to actually work have been reformulated and hardly ever work. Chemtool cold carburetor/parts dip is one that I miss.

The trick is not to overuse the product. They have a percentage of Stoddard solvent in them that is meant to break down carbon deposits (coking). The main focus is to break up the deposits and send them to the sump where they can be flushed out with each oil change.

Hello T., The old "L" head (side valve) engines were a lot tougher and better built than the modern overhead valve designs. I've seen a lot of the newer designs bend push rods and break a connecting rod, and "ventilate the engine block", but it was very seldom on the older "L" head design.

Does this deck assembly look similar to what your deck looks like? https://www.motoruf.com/n/partslists.html?id=50080370

All air-cooled engines build up sticky carbon on the piston rings and eventually it keeps them for sealing to the cylinder wall correctly. Marvel Mystery oil and Engine Restore gradually melts the carbon buildup down and the rings can work properly. I recommend you change your oil and use a...

I have used them for years without issue, but I also disassemble them and pack additional high temp bearing grease in the bearings because they often do not come much grease in them when new. Unfortunately, even the OE spindles come this way, and I think it is so they can just sell more in the...

Disconnect the kill wire and see if it has ignition fire. How are you checking for fire? A "Christmas tree" bulb style tester can be very unreliable. A spark test with and adjustable air gap is best to use. Next possibility is you got a bad "new" coil.

Have you verified this has a good deck drive belt tension and it is the correct belt? A wrong belt will sit too deep in the pulley grooves and slip especially when under load and cutting. I have seen many belts slip before and never make any noise.

Hello M., Welcome to the forum. We are all here to help when we can, but you need to include the build label information off of the chassis and the engine. The mower manufacturer does not make the engines used on their riders; they buy them from engine builders through private contract...

Apparently has a ground and a power to run the meter. Unplug it and tape the leads off.

I take that this is a 30-inch cut mower deck? What horsepower? I think this was a "manicure" trim mower deck design that was short lived. Not good for tall grass or general mowing of large areas. You have to mow with RPM on high and slow ground speed. It is a pain, but the blades need to be...

On one that old with the problem you described, I would replace the ignition switch. They do fail internally. Make sure you match up the new switch with the old one. They make a couple that look identical, but the internal contact locations are different.

That is to prevent "throttle hunting" especially when at idle. The rod ends have a very small amount of play in the holes they fit. The tension spring takes up that play so the throttle stays steady like it should. That spring shows to be stretched on the end quite a bit, so it may not hold...

Hi MParr, The engine serial number is: 5125324614. Those head number are the recommended replacement.

Thanks for the input V., I'm not going to waste time trying to "save" this pair of heads because it will likely be a repeat problem.

Thanks MParr, Those seem to be to most the common number heads shown and available.

I figured out how to get to the Rehlko parts break down for this engine and found it even more complex because they have a serial number break. I'm still confirming the numbers shown.

Hello MParr, I have not yet. I am thinking this was built in 2021 before Rehlko split off into its own division in 2024 from Kohler.

I have the heads off finally. I also removed the breather to verify it was not choked up with oil carbon. Cylinder have very good cross hatching with normal piston play. No scoring in the cylinders. Cyl. head #1 casting 32 494 29 Cyl. head #2 casting 32 494 30 I do not want to reuse the old...

I tried heating the intake valves with a propane torch after I tapped them open with a hammer and they stuck that way. With heat, the right side would slowly come back to closed. The left side stayed open after heating for a solid 5 minutes. When I pulled the intake, I can see the valve stems...

Hello MParr, Inside the crank case unknown but there is no unusual noise when cranking and both pistons move in the cylinders. I do not think the owner has done any adjustments or service except change the oil and filter and refuel. The oil appears to be way overdue because it is very black.

You are in way over your head. Look into getting a used engine or refit a new engine.

I vote for pulling the carburetor off, removing the bowl carefully so the bowl seal does not get damaged, then clean the gel out that used to be stabilizer and fuel. It is best to stay with the original carburetor if possible because the main and pilot jets have been calibrated to your motor...

I considered putting a trailer hitch on my RZT 50S and then started adding things up. For short pulls it would not be much of an issue, but the heat builds up quickly in the hydraulic drive motors. Water is approx. 8.33 pounds per gallon. Add the weight of the tank assembly and the trailer and...

Hello MParr, Thanks for the reply. I have not seen valve guides available for any Kohler engine in years. I will know more after I get past the rain we are having because the machine is outside. I don't have room to bring it in my 2-bay shop. I am going to try heating the intake valves before...

Hi Slomo, That is still the mystery I have to determine. It is outside and it is raining around here currently. I'm also going to verify the compression release has not been damaged before I dig too far into this engine. If it has, the cam will need to be replaced which just adds to the...

Hi Tiger, I almost installed in a couple of good pushrods until I went to check the intake valves individually and they would not budge while being pushed down by hand with a hammer handle. Both exhaust valves could be opened and spring right back like normal, but the intake valves stayed...

Ah, the illusive oil stick that has plagued owners for years especially if they are perfectionists.... Just think, engineers do this stuff to create confusion. If the level reaches the middle of the check/add range on the stick after checking a couple of times in a row, leave well enough alone...