"Mighty Mac" Log Splitter Help Needed

[tvoellin]

Hi, I just recently joined this forum. I am amazed at what I found as I looked for help. And unfortantely, my searches have failed me so I need to ask for some help. And using a log splitter is new to me (other than a maul )

I purchased an old "Mighty Mac" logsplitter with a 5hp 206cc Briggs and Stratton engine.
View attachment 240861
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I'm having some startup issues. It wasn't started for at least 18 months minimum when I purchased it. I changed the spark plug with a new one gap'd at 0.030". I removed the gas tank, drained and flushed with a little clean gas to get as much "crud" out of it as possible. But there probably is still some residual stuff in it because the fill hole doesn't allow for everthing to flow out completely when turned over to drain. I've removed the carburator and sprayed carb-cleaner through it as much as possible but didn't disassemble it completely. The fuel pickup tube is pressed into the carb body and has a screen over the end. I sprayed cleaner into it.

After I resassembled it, I added some gas and gave the carb one squirt of cleaner into the air port (with filter removed) and it started right up. I let it run for a while until it sounded like it ran out of gas. I added more gas. And subsequent starts are very difficult to get going (almost not at all) by spraying carb cleaner and choking. It will not start at all without cleaner sprayed. Do you think I need to remove the carb again and maybe completely disassemble? Does anyone have any tips to this or a drawings? Or is it not necessary and continue to spray cleaner?

And I don't understand the throttle mechanism. It is connected to a linkage down to what appears to be a governer from the engine. That linkage has a spring hanging from it but not connected to anything else. I'm assuming that when the engine begins to bog down the linkage will shift opening the throttle. But there is another rod vertical next to that linkage that goes to a pivot and then nothing. I thought the spring went to this pivot piece but it doesn't fit (probably a replacement) nor puts any tension on anything really. Can someone explain how this mechanism is suppossed to work and be setup or have a drawing/manual?

Thank you for your time,
Tim

 

[doobie57z]

get your serial number and Google "carb kit", when it comes you will remove the carb and you'll get needles and gaskets for $20 or sr go to the nearest Northern Tool or Tractor Supply and get a Chinese motor brand new for $100.

 

[Whitespider]

Wow...
At the risk of coming across a bit strong and offending you...
It sounds like you're not sure what you're doing and/or you don't have the needed basic knowledge of small engines...
Take it to a small engine/lawn mower repair shop and save yourself some headache.

 

[rmh3481]

Here is a video of a similar carb to give you a reference point. Its critical that you put the springs, and the diaphragms back in the exact same order that they came out of. Not a hard job at all and everyone has to start some where.

CARBURETOR Repair on Older BRIGGS & STRATTON 3.5HP Engine Part 1 of 2 - YouTube

 

[Oldtimer]

I must concur: your best bet here is to replace the engine with a TSC or Northern Tool unit.
At the same time, you probably want to replace the lovejoy connection between the engine and pump.
I have the same splitter myself. It has always run fine, except the time I broke the carb right off by backing into it with the plow truck. I bought a replacement from the small engine repair shop for $10 and managed to get it going as good as before. I'd tell you to do the same, except governor issues can be horrific...I have never had any luck tinkering with messed up governors. Once messed, always messed...

KOHLER® Command PRO® 7 HP Horizontal Crankshaft Engine - 2106941 | Tractor Supply Company
Briggs & Stratton Horizontal Engine — 205cc, 800 Series, 8.0 Gross Torque, 3/4in. x 2 27/64in. Shaft, Model# 126332-1036-B8 | Briggs & Stratton Horizontal | Northern Tool + Equipment
Heavy-Duty Half Lovejoy Coupling — 3/4in. Size | Couplings | Northern Tool + Equipment

 

[Whitespider]

Once messed, always messed...

Small engine governors are not complicated or difficult to adjust… the thing is they likely should never need adjusting (messing with). Usually when people feel the need to “mess” with a governor it’s because they have some other problem, such as a worn-out and sloppy carb throttle shaft, or slopped-out linkage, or, as in the case with small B&S engines with air vane type governors, the air flow to the vane is restricted by debris, or maybe it’s as simple as a dirty air filter. Almost everybody owns a small engine or two (like a lawn mower or snow blower), but less than 1% of those owners understand what a governor does or how it works… They don’t understand just how important a properly operating governor is to a small engine, so in their ignorance they “bend” things like arms and linkage, and stretch or cut coils off the spring, those types of “adjustments” are guaranteed to always make things worse… sometimes with catastrophic results.

“Bent” parts can usually be straightened back into original form (unless they’ve been kinked), but a “messed with” spring has to be replaced with the exact replacement part specified by the manufacturer… any other spring is worthless. Engines with adjustable type governors are simple to “adjust”… usually they consist of a governor shaft with an arm clamped to it in some way. “Adjustment” is done by “un-clamping” the arm from the shaft, pushing the arm until the carb throttle is wide open and hold it there, turn the governor shaft (in the same direction you moved the arm) until it stops, tighten the clamping devise… done! Normally the only time you need to “adjust” the governor arm is when you’re required to replace it for what ever reason, or sometimes a “sloppy” linkage issue can be remedied. On a lot of governor set-ups there will be a screw with jamb nut that pushes on another lever, that is used to set maximum off-load RPM after the governor arm is adjusted… requires a tachometer.

Those are just basic instructions, each set-up may require the loosening or disconnection of something to accomplish the basic… depending.

 

[Oldtimer]

Small engine governors are not complicated or difficult to adjust… the thing is they likely should never need adjusting (messing with). Usually when people feel the need to “mess” with a governor it’s because they have some other problem, such as a worn-out and sloppy carb throttle shaft, or slopped-out linkage, or, as in the case with small B&S engines with air vane type governors, the air flow to the vane is restricted by debris, or maybe it’s as simple as a dirty air filter. Almost everybody owns a small engine or two (like a lawn mower or snow blower), but less than 1% of those owners understand what a governor does or how it works… They don’t understand just how important a properly operating governor is to a small engine, so in their ignorance they “bend” things like arms and linkage, and stretch or cut coils off the spring, those types of “adjustments” are guaranteed to always make things worse… sometimes with catastrophic results.

“Bent” parts can usually be straightened back into original form (unless they’ve been kinked), but a “messed with” spring has to be replaced with the exact replacement part specified by the manufacturer… any other spring is worthless. Engines with adjustable type governors are simple to “adjust”… usually they consist of a governor shaft with an arm clamped to it in some way. “Adjustment” is done by “un-clamping” the arm from the shaft, pushing the arm until the carb throttle is wide open and hold it there, turn the governor shaft (in the same direction you moved the arm) until it stops, tighten the clamping devise… done! Normally the only time you need to “adjust” the governor arm is when you’re required to replace it for what ever reason, or sometimes a “sloppy” linkage issue can be remedied. On a lot of governor set-ups there will be a screw with jamb nut that pushes on another lever, that is used to set maximum off-load RPM after the governor arm is adjusted… requires a tachometer.

Those are just basic instructions, each set-up may require the loosening or disconnection of something to accomplish the basic… depending.

That's good info! Thanks!

 

[Somesawguy]

There is usually a diaphram between the carb and the tank. They tend to get old, and lose their pumping ability. Get a carb repair kit, and replace that at the very least. Spray out the passages you can get to, and make sure the pickup screen on the bottom of that plastic tube that goes into the tank isn't clogged up.

Usually, that will take care of it on those old engines. They are pretty tolerant of slight mis-adjustment.

You should check to make sure the low and High jet screws are adjusted correctly. If you've messed with it, then try starting at 1.5 turns out from bottomed out. That should get you ballpark.

 

[jags]

Also, I find that when working on small carbs, one of my go to tools is a set of torch tip cleaners. They can be bought at most hardware and farm stores for cheap. It gives you a multitude of sizes of wire that will allow you to poke and probe (and clean) all the little carb ports. Works well when they are all gummed up.

 

[tvoellin]

Well thanks everyone for the tips. I actually didn't really have to do much more. I took the needle jet out one more time, cleaned the tip and sprayed some carb cleaner into there, more into the throttle body and more into the gas tank. It started up. I've been starting it every day for about a week now and letting it run for a few minutes. I haven't even been using carb cleaner. I found a happy place with the jet setting so that when I open the throttle quickly it doesn't stall. Two pulls and it starts now. The first with the choke closed and the next with it just slightly open and it starts right up. Let it idle for about 20 seconds then open the choke all the way and it runs very smoothly.

But I still believe I have an issue with the automatic governor. I was going to make the adjustment on the lever arm attached to the shaft exiting the lower section of the engine as Whitespider recommended. But, I was observing the shaft that it is clamped onto. It has a slot on the end so I can clearly see movement. It is not rotating at all when the engine is loaded. I would think that there would be some rotation even with the arm connected? Or is the load on the arm going to the throttle more than the force applied by the rotating shaft? Do you think unclamping would allow for me to see rotation? For the throttle to open, it doesn't seem to have to rotate very far at all. Does anyone have any knowledge of these older automatic governors?

Thanks so much,
Tim

 

[Whitespider]

Do you think unclamping would allow for me to see rotation? For the throttle to open, it doesn't seem to have to rotate very far at all.

No. If you un-clamp the arm from the governor shaft you won't see any movement (or rotation) while the engine is running because without the "spring" pressure applied through the arm it will just move all the way to the "stop" and stay there. The governor shaft doesn't have to (as you say) "rotate very far at all"... it only needs to move the throttle in tiny increments, just enough to maintain RPM. When that governor shaft moves (rotates) just a tiny, tiny bit the far end of the arm moves a lot farther... and the whole apparatus controls a throttle that only moves something less than an inch from stop-to-stop (so you'll never notice any governor rod movement as the engine is running and vibrating). What do you mean when you say, "It is not rotating at all when the engine is loaded"... How are you "loading" the engine? Where you want to look for movement is at the throttle on the carb, not the governor itself. Take the air cleaner off (put the screw back in or it won't run right) and watch the throttle on top of the carb as you "load" the engine... it should move around a little as the governor "tries" to maintain RPM. If the throttle is moving and hunting as you vary the load on the engine, then the governor and linkage is working... SO DON'T MESS WITH IT!

 

[Whitespider]

I was going to make the adjustment on the lever arm attached to the shaft exiting the lower section of the engine as Whitespider recommended.

No, no, no, no, no... Go back and read it again.
First you need to positively determine if the governor is working or not... and, if it is working, I actually recommend you don't screw with it at all!!!!

 

[half]

First thought

OK First thing I would do is get the govenor checked by someone who knows what they are doing. And not Joe down the road who had a half sister who is married to a guy that used to work at a mower shop.If you do it wrong you can detroy the engine

Get a B/S service shop to do it. and they will probably tune it for you as well. Some briggs have air govenors, usually mower engines and industrial engines have mechanical. you need the model number to get any information. that is on the recoil cowling at the top. there are so many different setups for different applications. Manuals for them are around,try the b/s site once you have the model numbers. and If you have a real friendly mower shop they could photocopy a set for you. we had them at work and they are about 3 in thick, covering all models

B+S motors of that age have 25 thou plug gap the engine should rev to about 3500 tops and the govenor will hold it there.smooth and full revs should be smooth, no hunting. too big a plug gap can cause hunting at full revs.Under load the engine should increase in tone as the goveror opens the throttle to provide more power. tuned right and looked after the old B/S will go for years