135 Gasoline model gas problems

   / 135 Gasoline model gas problems #1  

TnAndy

Veteran Member
Joined
Aug 9, 2013
Messages
2,001
Location
East Tennessee
Tractor
Yanmar LX410...IHI 35J excavator Woodmizer LT40
Trying to help a neighbor of mine with an older MF135 with gas engine. It only ran enough for him to get it over to my shop with the choke pulled all the way out....push it in even a little, and it would die. He bought the tractor from a guy that almost never used it....only 600hrs on the meter, it has spent a lot of time parked in a shed over the decades.

What we've done so far:

Pulled the carb, a Zenith model, took it apart, soaked in a gallon can of carb cleaner over night, blew every passage out I could see to blow out, used a carb kit to rebuild...but it had no new jets...mainly gaskets.

We have also removed the fuel tank (to install new spark plugs), cleaned it out.

Installed a new glass fuel bowl on the tank (the cutoff valve was leaking on the old one), blew out the fuel line from the bowl to the carb, installed a new fuel filter at the carb, have good, clean fuel flow TO the carb.

Checked the solenoid in the float bowl....it retracts as it should when power is applied to it.

New air filters, inner and outer.

Replaced points, plugs, plug wires, condenser, cap (which WAS badly pitted at the 3 contact points), rotor.

Results ?

Can now get it to idle once warmed up with no choke....but at 1500-2000 rpm, still needs about 1/2 choke, or it spits/sputters/dies....but runs fine with the choke half pulled out.....which indicates to me still not getting gas thru the main jet (and I have no idea which of the jets IS the main jet). It's definitely running better than when it limped in my door, but it's certainly not up to par yet.

Carb only has what I think is an air screw (according to one pic I found) on the side next to the inline fuel filter. I set it 1 1/2 -2 turns back out from bottomed all the way in, doesn't seem to affect idle until I back it way out....like 5 turns, then it wants to die at idle. No other external adjustments I can see other than I could adjust the throttle cable connect point....but haven't....seems that would only increase or decrease the idle speed.

Would welcome any help at this point.

Thanks.

Andy
 
   / 135 Gasoline model gas problems #2  
I think that carb needs a trip through one of those "sonic" cleaners...

SR
 
   / 135 Gasoline model gas problems #3  
From your description (no adjustmenmet screws) you may well have the wrong carb. I haven't worked on many 135s but have done several T0s and MFs. All of those had two adjustment screws and non had filter at carb nor solenoid you described. See if you can cross referance the carb model #. That same Continental engine was used in several applications with various fuel,ignition and governor arrangements that are not interchangeable unless everything is changed togeather. Did you confirm venturi was installed correct side up? If there was no venture in throat you definatly have wrong carb. If ignition is off bad enough it will not run on anything short of a rich mixture. Make sure it's in time,advance weights are not stuck or missing parts and spark is strong. For what it's worth,that is a good model tractor so it's worth investment if new parts are required.
 
   / 135 Gasoline model gas problems #4  
I once bought a generator with an engine that had no adjustment screws. Ran but not well. I finally bought a new carb which came with normal adjustment screws. I looked closely at the old crab and after wiping grease away I could see where the screws USED TO BE. Runs fine now.
 
   / 135 Gasoline model gas problems
  • Thread Starter
#5  
From your description (no adjustmenmet screws) you may well have the wrong carb.

Thanks for the reply !

Pretty sure it's the carb that came on the tractor.....I see no reason they would have changed it given the low hours. Didn't look to me like it had ever been off the manifold.

There is a 'port' hole on the back side (left side facing tractor operator) where an adjustable jet screw might go, but it is plugged with a metal cap, as are a couple other places on the carb body....doesn't look like one was ever there. Neighbor's book does show an adjustable needle screw on both the front and back side (right and left side). BUT when shopping for a carb rebuild kit, it appears several different carbs were used on them....this one is definitely a Zenith....found that in the carb body when the crud was removed.

The venturi is there, and "murphy proof"....only goes one way the base seats to the carb body...you can't get the carb halves back together if not seated right. (Yeah....ahahhaa....ask me how I know)

I did not time the ignition, but I do have an old timing light (wow....haven't used it in 25 years or more). I looked for timing marks on the front crankshaft pulley, as well as some kind of mark, arrow, slot, etc in the front casting....rotated the pulley a full 360 degrees with a real good flashlight on it, and I don't see a thing resembling a timing mark. I did read somewhere about a plug you have to pull out (of the engine case ?) to see the timing marks, so I looked for something like that and see nothing. The book the neighbor had was useless...says "take to a dealer for engine timing".

I thought about getting #1 piston to TDC, and simply make my own mark on the front pulley/case....if nothing else, I could see if the distributor is advancing the timing when rev'ed up.
 
   / 135 Gasoline model gas problems
  • Thread Starter
#6  
I think that carb needs a trip through one of those "sonic" cleaners...

SR


Hmmm....will have to call around and see if I can find someplace that does that. Thanks.
 
   / 135 Gasoline model gas problems #7  
The timeing marks are on flywheel. Cover is mounted in similar position and fashion as starter motor,on other side. Tractor Supply Company stock's "IT Manual".
 
   / 135 Gasoline model gas problems
  • Thread Starter
#8  
Ah...the flywheel end....yeah, wasn't looking there, for sure. Thanks !
 
   / 135 Gasoline model gas problems #9  
You haven't identified the engine...is it a 3 cyl or a 4 cyl? 3 is a Perkins/4 is a Continental. Continental's came with M/S carb...mo' info needed... BobG in VA
 
   / 135 Gasoline model gas problems #10  
You haven't identified the engine...is it a 3 cyl or a 4 cyl? 3 is a Perkins/4 is a Continental. Continental's came with M/S carb...mo' info needed... BobG in VA

Whoaooo,if it's a Perkins there's the problem,,,,,,,,,,,,,,,,,,,,,,,it didn't have a carburetor from the factory.:tractor: Yes,all gasoline models came with MS,partly why I brought up improper carb. Zenith replacements can be had but how often does one discard the carb on old tractors rather than rebuild? That solenoid and in carb filter coupled with Zenith sound's like carb was designed for a genny or irrigation pump.
 
 
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