View Full Version : Great Site!! Briggs Question

05-16-2007, 08:33 PM
I will begin with this site is excellent would have loved to have run across you folks years ago.
My Problem, mower starts instantly and only at full throttle and choke. Once running will die if choke is fully depressed. Can mow at a snails pace with no power at about 1/4 choke. Interesting part..Mower during snails pace operation will occassionally "cough" throw a lot of bluish white smoke and run full rpms and power...this never lasts longer than a few seconds.

The Mower. MTD
The Motor:
16HP Twin II Model 42A707 Type 1238 01 Code 9602125B
Three screw fuel pump.

Attempted fixes so far. Fuel pump rebuild kit..Very thouroughly cleaned carb drained all fuel. Rinsed tank (with fuel)..new fuel lines..new fuel filter...twice..first was cheapy with wire screen second time with bosch with paper element...and needle valve replaced.

Inherited this from grandfather and even though it is not a classic or collectors mower it still holds value to me and is irreplaceable. Really want to get this thing going right. Thanks if you have advice of any kind.

Bill Kapaun
05-16-2007, 08:51 PM
Thank you for posting the engine numbers!

What do you mean by choke "depressed"? Do you mean closed or open?

You can download an IPL at-

Did you clean the Main Jet? Part# 117B

05-16-2007, 08:52 PM
should have mentioned compression check was fine.
Further Question
If I am unable to repair with the info I anticipate from you folks; is Briggs repair manual 271172 the right repair manual for this motor?

05-16-2007, 08:59 PM
117B This is the jet that screws into the body with an allen wrench if I am reading this diagram correct. I did remove this and clean it and the hole it came out of. The parts house guy assured me that this needed just to be snugged back in and no specific torque was needed.
By depressed. On this mower the choke is operated by pulling out or pushing in. When I say depressed I mean pushed in. This is open I think. If that doesn't sound right let me know I will go pull air filter real quick.
Thanks for the quick response.

Bill Kapaun
05-16-2007, 09:11 PM
"is Briggs repair manual 271172 the right repair manual for this motor?"
According to the Briggs website it is.

"This is open I think."
Really need to know if open or closed. Else I think I might head down the wrong fork in the road.
Closed is where you normally start a cold engine.

05-16-2007, 09:22 PM
Sorry for the odd terminology, so what are you thinking?

Bill Kapaun
05-16-2007, 09:43 PM
"Once running will die if choke is fully depressed. "
I need to know if by depressed whether you mean the choke is open or the choke is closed.
"depressed" is not a word commonly used to describe a choke position.
IF one is trying to troubleshoot the wrong scenario, they just waste a lot of time & effort.
Speaking of time, supper is ready.

05-16-2007, 09:50 PM
Depressed = open
I am saying the mower dies when I open the choke all the way. Funny it's supper time here as well. Spaghetti anyone?
Thank you for taking the time to talk to me.

Bill Kapaun
05-16-2007, 09:51 PM
I think maybe I understand the terminology problem.

I need to know if the choke valve pn# 108A is blocking the air flow or not.
Blocking is a CLOSED choke
Not blocking is an OPEN choke
When running, closing the choke often results in the engine stalling out. You are flooding it.

Bill Kapaun
05-16-2007, 11:11 PM
"I am saying the mower dies when I open the choke all the way."
This sounds like the engine isn't getting enough fuel for some reason-
To Verify-
Do you have a pump oiler or similar that you can put a bit of gas in? With the engine running, pump a bit of additional gas into the carb throat. IF engine picks up, it indicates insufficient fuel. IF so, keep pumping faster, while opening the choke to see if you can obtain higher RPMs. On RARE occasion, that might dislodge any SMALL specks of crud.

Often when disassembling/re-assembling fuel lines, filters etc., little bits of debris get dislodged and flow to the carb.
Possibly, a larger "chunk" may be restricting the fuel inlet to the carb just before the needle & seat. If this is the case, you would have to remove needle again and "blow" back through that area to force any chunk back out. (The spray tube on your carb cleaner should work, or compressed air).

2.Possibly one of the check balls in the fuel pump body (pn# 391) is not closing fully. (speck of crud again). OR one of the passages is clogged.
2B. The breather hose going to the fuel pump is leaking. The pump needs the "air pulses" from the crankcase to move the diaphragm to pump.
2C Crankcase breather reed valve is clogged. (no pulses)

I would also reinspect the Main Jet again. Look for ANY TINY hole you might have missed. Some jets may have more than 1 hole.

Look for obvious air leaks on carb/intake & intake/engine mounting surfaces.

That should keep you busy for a bit.

05-17-2007, 07:14 AM
Try opening (turning counter clockwise) reference # 147A, This adjuster does effect high speed running also.

If still no improvement go back to the fuel pump and make sure reference # 860 springs stayed in place during assembly, A little dab of grease on the tabs will hold them in place during assembly.

05-17-2007, 02:06 PM
Gentlemen thanks for all of the advice I'm at lunch now but will be getting home around 5:30 Central and tearing into these suggestions

05-25-2007, 06:28 PM
I have implemented the suggested remedies with no appreciable change in performance. However before I bothered you all any more I read some other posts here regarding power loss, coming across the posts that mentioned twin cylinders engines running well on a single cylinder until placed under load sounded a little like my problem. Long story short pulling the left plug on the motor results in instant death, pulling the right plug on motor does not effect it. In addition after the right side plug wire jarred my fillings when I accidentally touched the screwdriver shaft I had wedged in there while my wife hit the starter. So I manned up enough to touch the screwdriver I was using after not seeing any spark jump to block while running on the left side. On this side I can feel a pulsing electrical charge, a little worse than touching a 9 volt to your tongue, but I could literally hold the thing while the motor was running for around 20 seconds.
This leads me to believe I have led you all astray and I in fact have a spark problem. Information on how to proceed would be greatly appreciated.

05-25-2007, 08:02 PM
Just for giggles, Remove both spark plugs and install one in the suspected bad wire then hold the hex on the plug to any metal part on the engine (preferably not painted) and have the wife spin it again.

If still no spark the flywheel cover must be removed and the coil replaced. Use any business card to adjust the air gap.
Rotate the flywheel magnet away from the coil, Install the new one but pull the coil away from the flywheel and just snug the screws. Rotate the magnet to the center of the coil and insert the business card, Loosen the screws and let the magnet pull the coil to the card then tighten the screws. Hold pressure on the end of the card and rotate the flywheel to remove the card.

05-25-2007, 11:46 PM
Just a side note but the pic you use on your sig looks like the equipment I used when I worked at a lawn care service for several years in High School and a couple of summers in college. Don't laugh they didn't make me work on them, just drive them, 12-14 hours a day. We used M&W mowers with a couple of Whites and Grazers and one Zipper. All were similar to your pic but the headlights look different on your pic than any of the stuff we were using. The parking brake on your pic is on the side like all but White, but color is wrong for all but Zipper. Is the pic a Zipper model I just haven't seen? And does anyone still make this style of equipment? No one around here sells anything like it anymore. All we have around here now are Dixie Chopper, Skags, Grasshopper, Gravely and the like.

05-26-2007, 09:17 AM
Don't laugh they didn't make me work on them

Lucky you !!! These things are a pain to work on with the engine down under all that sheet metal.

Is the pic a Zipper model I just haven't seen? And does anyone still make this style of equipment?

No it's not a Zipper and they are still built today, It's a Ingersoll.


It's the twin brother to the Grazer and most all parts are interchangeable between the two. The White was a knock-off from the Ingersoll/Grazer with a few cosmetic changes.

We were a dealer for these units some 10yrs. ago so I got a super deal on the last one we had in stock, They never really gave that many problems but I did have to strip a couple body's off to do major engine repairs. They just didn't catch on in our area so we dropped the line.

I also have a complete parts unit with a new short-blocked engine so mine will be mowing for years to come, Oh....One finds out quick, Never panic stop from full mowing speed.....


05-29-2007, 09:09 AM
I have to differ with you on that one. It takes a little to master carrying the tailwheel (or wheels we built custom dual sets for most of ours) once you have it down no other mower out there can put that much weight on the drive wheels, that makes it great on slopes (backward) and on slick grass. After a year or two working there I could take an M&W (later purchased by Ingersoll Rand according to my old boss) on asphalt cut the sticks back get the mower to rear up (tailwheel off ground) and spin it 360 before letting the wheel hit the ground again. Lot's of fun to operate. Quick tale, after being told by the Dixie Chopper rep to forget how we back the M&W's around on steep slopes and just take the Chopper straight up and down hills I took a chopper up a hill that I mowed every week with an M&W and wound up at the bottom of the hill in a ditch with the mower pointing stright at the sky resting on the frame and motor. No question the choppers were faster but while I was there we never had an operator that could take them on the stuff we took M&W's on.

05-29-2007, 11:26 AM
I dealt with this crap for years on my 10hp Briggs Intek pushblower, it would run dandy for however long and then act stupid, same thing with that choke lever I'd have to choke it until it decided to act right again.

I replaced air filter and precleaner, fuel filter, coil, spark plug, ignition switch, thoroughly cleaned the carb, even replaced the head gasket and you name it... Nada.

What it was, once I pulled the carb float bowl off, there was gunk or some dirt particles floating around... I cleaned all that out real good with some carb cleaner and put it back together, runs great now.

06-04-2007, 10:20 AM
Takes me forever to get time to work on this thing, I suppose lucky for me it hasn't rained here in 19 days and my yard is dead as a wedge anyway. No spark on the test Rob mentioned, so I'm going for the coil, just a little embarrased here but cannot find a part called "coil" in the IPL found something that looks like what I want but called another name. Advice on part number and correct nomenclature here would be appreciated.

06-04-2007, 10:56 AM
Sorry, If I use the technical term of armature-magneto or control module as Kohler calls it most people would http://www.gtr-game.com/forums/style_emoticons/default/blink.gif so most understand the term coil.

Below is the correct part # and term for the part you need;


You can click add to cart and purchase right here or go to your local dealer.

06-04-2007, 09:23 PM
You folks are great, I wish everyone were as knowledgable and helpful as you folks have been. Let me know if anyone needs any Phase II MS4 compliance advice I can help with that. I have ordered the coil I need, stopped in at the local parts house it was actually about $5 cheaper than online 10 if count shipping.
Moving on, let me know if I have broken protocal by changing subject within the thread. However I figured it is helpful to those who post if they know my skill level. While my mower has been down a coworker gave me another mower that a renter left at his property. I haven't gotten this to run but it is in very nice shape physically. A Murray 10/30, I probably would have chucked it or ebay but the wife thinks it is cute and she wants it fixed for her.
The Stats:
Murray 10/30 Model 30550 B
Engine Tecumseh TVXL220 157243A

The problem: Some one removed the key switch, I have gotten the mower to turn over as is but the wires are nutted together 2 yellows together and 2 Reds together the black is capped by itself. I have pretty well ruined my gasket scraper jumping the solenoid and I picked up a key switch at the parts house today. The mower has not started (despite a full blast of ether down the breather) but the wire does spark. I cannot find a wiring diagram for a mower like this anywhere. Any advice.

Preview of things to come. A different coworker offered to sell me his John Deere 110 (late 60's early 70's) for $175 and I have agreed. His solution to my problems is that things aren't built like they used to be and I tend to agree. In addition like I stated the MTD has sentimental value and I want to use it very lightly in the years to come. The JD has a K241S that replaced the original K181 in the early 80's, It has been derelict in a barn for 10-15 years. No Rust! I am sure you all will hear from me on this project in the future..I will try not to make a pest of myself. Thanks ahead for any info on the murray.

Bill Kapaun
06-04-2007, 10:10 PM
Over on GW, there is a poster that has a Craftsman 1030 which just happens to be made by Murray and has a TVM-220 engine.
He could probably help you with the wiring diagram

06-04-2007, 10:20 PM
This one is a year or two newer than yours but should show what you need to get it wired back up.


Bill Kapaun
06-04-2007, 10:31 PM
Also, go to the Sears website and use model# 5022561321
That may give you a parts list

06-05-2007, 07:44 AM
Looks like I have the switch rather correct. However I am two wires short. Above diagram has a red and yellow on the headlight circuit, mower only has red. Not plug there for an additional wire. There is also no yellow wire plugged into the engine as shown above. I wired up everthing I could ID for sure and it does work. The seat safety switch on this mower has been defeated by jamming a wad of wire into the connection. On the switch now wired when I turn it to light the light comes on and when I go to run the light turns off and the engine does turn over in the start position. Is the light supposed to be off in the run position? If the safety systems have not been defeated correctly would the mower still turn over and just not start?

06-05-2007, 12:03 PM
If the safety systems have not been defeated correctly would the mower still turn over and just not start?

Yes it could, Some are wired in that way. Disconnect the Kill wire from the engine (Yellow wire in above diagram) then check if it will start (spark at plug). If is does there is a bad safety switch in the system.

If it still won't start and there is good spark at the spark plug there is most likely a mechanical problem with the engine.

Bill Kapaun
06-05-2007, 02:36 PM
"I turn it to light the light comes on and when I go to run the light turns off and the engine does turn over in the start position. Is the light supposed to be off in the run position?"
If your switch has 4 positions, they would probably be-
Run with lights
After starting, you have to move the switch back a position from run, IF you want lights. (if it's working correctly)

06-08-2007, 09:01 PM
Back on the original MTD, I have replaced the coil. The parts house guy gave me a piece of microfilm and told me to bend double for gap. He said slightly more accurate than a business card (should I mention I do own a feeler gauge?) I also used a small steel brush to clean the flywheel where it passes the coil.
The result, the mower starts and runs like a top, I have not reassembled the breather and the egr(?) is blowing quite a bit of blue/white smoke however that is not big problem.
The problem, runs fine full rpm at standstill, once hydrostat is engaged will run ok at crawl, attempt to speed up and engine will attempt to die, close choke and the engine will catch and keep running, any attempt to put a load on the engine produces this result. I reread what we discussed earlier and Bill mentioned a crankcase pulse. That is the one thing you all have suggested so far I haven't tried. How do I check that and do you all still think that may be part of the problem. Once again thanks for all of the help I hope we are closing in on the problem.

Bill Kapaun
06-08-2007, 09:14 PM
Hook up the breather .
Is the fuel pump "pulse" line hooked up, with no leaks?

06-08-2007, 09:44 PM
I reread what we discussed earlier and Bill mentioned a crankcase pulse. That is the one thing you all have suggested so far I haven't tried. How do I check that and do you all still think that may be part of the problem. Once again thanks for all of the help I hope we are closing in on the problem.

As Bill suggested re-install the air filter assembly, These fixed jet carbs are jetted to run with the filter in place. Would most likely run lean removed.

Remove the bottom hose from the fuel pump, There should be enough fuel in the carb to have someone start the engine while you lightly hold your thumb over the end of the hose and feel for a impulse of engine vacuum.

Another thing;
Remove the large plug covering the main jet while holding a small container under it and see how much fuel is in the float bowl, Should be equivalent to half full in the bowl. If that looks OK then while the plug is out take your carb spray cleaner with the little straw and poke it into the main jet and give it a good squirt while looking down the throat of the carb. You should see a good spray coming out of the little brass pipe. Don't look too closely and get it in your eyes, That hurts like a sob.

06-08-2007, 09:55 PM
Out of carb clearner. Brake cleaner ok?

06-08-2007, 10:00 PM
If it has the little straw, I prefer the carb. cleaner because it cuts gum/varnish better.