# ***Mud Motor Repair Help Needed***



## marshman (Nov 29, 2005)

talked to Jeff over at Freeway sports and he said that he has seen those engines fail the fuel pump if there is too much oil in the crankcase. Since the fuel pump is driven off of pressure this stops the flow of gas thus cutting the motor off. I know that there is oil in it but Jeff says that to double check that before bringing it in for a $150 carb rebuild. I plan on running it tonight and will post back tomorrow. 

1. double check oil level, if over hatched mark reduce to just below hatch mark. 
2. if the oil level is not the issue, disconnect the oil cut off as listed above and run.
3. if all else fails drink beer until bedtime and bring motor to mechanic in morning

thanks again...

marsh


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## Shiawassee_Kid (Nov 28, 2000)

good luck. i just fixed my chainsaw with a very similar haunting problem that's been plaguing me for 2 years.


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## FERG 06 (Oct 6, 2006)

marshman said:


> talked to Jeff over at Freeway sports and he said that he has seen those engines fail the fuel pump if there is too much oil in the crankcase. Since the fuel pump is driven off of pressure this stops the flow of gas thus cutting the motor off. I know that there is oil in it but Jeff says that to double check that before bringing it in for a $150 carb rebuild. I plan on running it tonight and will post back tomorrow.
> 
> 1. double check oil level, if over hatched mark reduce to just below hatch mark.
> 2. if the oil level is not the issue, disconnect the oil cut off as listed above and run.
> ...


Geez, I'll tune it up, change the oil (& filter if it has one) and go through the carb for $150!
Take it off (the carb that is), drain the fuel and mail it down to me. 
Just saying.

Typical riding mower/lawn tractor:
Tune up, oil change, fuel filter, sharpen blades, check belts, air up tires, grease wheels and front axle - about $125-$130.

For me to go through a carb is about half what you were quoted.
Serviced 330 units last year.
Referances from M-S's can be provided if necessary.

Just throwing it out there.


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## BLS (Dec 12, 2007)

Your right on that, $150 is a bit high. Heck Marshman you by the kit I will rebuild it for free, you will have about $20 to $30 bucks in kit and cleaner. I have been running into a lot of carb issues because of this speedy refinded gas we buy. If your motor is an 01 you will have smaller jets than lets say my 86 John Deere tractor. With these smaller openings it does not take much. But I would try the oil things you mentioned first before spending anymore money. Let us know what you come up with.


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## DuckMan87 (Jun 11, 2009)

just throwin it out there bein i dont kno the motor setup...are u possibly sucking air?


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## marshman (Nov 29, 2005)

well i didnt have a chance to dink with the motor last night due to a late night of work. However, it is on the top of my list for the weekend between that and the beer tent at the showboat in chesaning!!! I know, I know priorities first...I plan on tearing into the beast on saturday afternoon and giving it a test run on sunday

Another ? 

To eliminate future issues providing i get the carbs / oil issue figured out

1. Will running 92 octane hurt the motor? I know it will burn hotter but will this cause other issues?

2. Can you run two fuel filters in line with one another without causing fuel dilvery issues to the fuel pump? 

3. Jeff (freeway sports) said that the Vanguard motors will run smoother with a synthetic oil (amsoil) (mobile1)? Since it is a smaller motor that only gets change every 20 hours I dont have an issue with spending the money....does anybody else run the synthetic in their mud motor?

thanks again for all the suggestions and comments.

Ferg- i might take you up on the carb rebuild providing I cant find somebody to help me out at the shiawassee flats meeting next tuesday...thanks

~Marsh


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## duckbuster808 (Sep 9, 2005)

marshman said:


> well i didnt have a chance to dink with the motor last night due to a late night of work. However, it is on the top of my list for the weekend between that and the beer tent at the showboat in chesaning!!! I know, I know priorities first...I plan on tearing into the beast on saturday afternoon and giving it a test run on sunday
> 
> Another ?
> 
> ...


We run Synthetic in ours and it runs great.....We have also run 93 octaine in ours and it seems to run better. We tend to get a few backfires from the engine with standard gas and now that we run premium we don't have any problems...Goodluck


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## FERG 06 (Oct 6, 2006)

Alot of small engines call for running 89 octane. That said and me knowing better I've never run more then 87 and get alot of life out of my motors. Most probs come from lack of oil changes and running old fuel (which doesn't burn properly resulting in carbon build up and clogged rings).

Duckbuster - when did you get back firing? Alot of the "big" small engines would backfire when shuting them down if it didn't idle long enough. That's part of the reason for the fuel shut off solenoid on most carbs now.
I use to here one of my crew load a commercial mower on the trailer and turn the key off w/o slowing it down and I'd say "wait for it" and sure enough, BOOM. When I got back to the truck I'd dish out a reaming to someone. Had mufflers blown up from that.
If it would back fire will running then you probably had some buildup on the valves which got cleaned up by the premium fuel.

Marsh:
If the carb needs to be gone through you probably don't need a carb kit which includes the main jet, nozzle, needle and seat, seals and gaskets.
I usually just clean'em out and replace seals and gaskets.

It only takes a little bit of water in the fuel to mess 'em up and they don't run. Being a mud motor, that's another possibility.
Another thing:
Does it have a fuel shut off solenoid on the bottom of the carb? Could have an intermittent prob w/that solenoid.

Here's how I'd approach it.
If it shuts off while running at higher RPM's, I'd make sure it has the proper amount of oil in it and unplug the oil sensor wire.
If it still does the same thing, Pull the choke out halfway or so. If it runs better you're not getting enough fuel.
If it makes no difference, unplug the "kill" wire and the coil will fire all the time.
Run good now? you've got a wire/switch prob.

At least that will give you alot of info and provide alot of clues for whoever you take it to and should save you some money since most places charge by the hour and a good tech will take all those clues and put his head to work before his hands.


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## duckbuster808 (Sep 9, 2005)

FERG 06 said:


> Alot of small engines call for running 89 octane. That said and me knowing better I've never run more then 87 and get alot of life out of my motors. Most probs come from lack of oil changes and running old fuel (which doesn't burn properly resulting in carbon build up and clogged rings).
> 
> Duckbuster - when did you get back firing? Alot of the "big" small engines would backfire when shuting them down if it didn't idle long enough. That's part of the reason for the fuel shut off solenoid on most carbs now.
> I use to here one of my crew load a commercial mower on the trailer and turn the key off w/o slowing it down and I'd say "wait for it" and sure enough, BOOM. When I got back to the truck I'd dish out a reaming to someone. Had mufflers blown up from that.
> ...


We'd get the backfiring problem when we would run for a longer distance up the river, or esp. on colder days when we'd run for short distances....


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## FERG 06 (Oct 6, 2006)

duckbuster808 said:


> We'd get the backfiring problem when we would run for a longer distance up the river, or esp. on colder days when we'd run for short distances....


Backfiring? or Misfiring? Misfire is more of a cough. Backfire is a POW,bullet shot, you know, flame shooting out the muffler or carb. Something that'll make your ears ring.

Backfiring while you're running under load? Don't know what motor you got but 2 things come to mind:
1) could have some carbon buildup which increases the compression ratio and covers the valves. Problem went away with running higher octane. Premiums usually have cleaners in them.

2) You might have a valve staying slightly open if the rockers are too tight. Required maintenance is to adjust rockers after so many hours. Hours vary by brand.

Cold misfires and aren't too unusual. Air cooled engines take a long time to warm up in the cold being that there is no way to control the incoming cooling air (at least on all the engines I've seen). As an example, Echo warranty will pay for 5 min warmup time before a carb adjustment is to be performed. And that's at normal shop temps!
Some engines that are intended to run in the cold will have a plate that you can move in the air cleaner to pull warm air into the carb from the fan housing.

Hope Marsh gets it worked out. Will be curious to find out what the problem was.


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## duckbuster808 (Sep 9, 2005)

FERG 06 said:


> Backfiring? or Misfiring? Misfire is more of a cough. Backfire is a POW,bullet shot, you know, flame shooting out the muffler or carb. Something that'll make your ears ring.
> 
> Backfiring while you're running under load? Don't know what motor you got but 2 things come to mind:
> 1) could have some carbon buildup which increases the compression ratio and covers the valves. Problem went away with running higher octane. Premiums usually have cleaners in them.
> ...


 

We are running a 35 HP Mud Buddy Short Shaft, on an 18ft Gator Trax boatt.....We're talking backfire....POW lol....We've had the problem fixed since running the Premium through it, so chances are there was a small amount of buildup....There's deff. alot of good info in theis thread. Hope everything works out for you Marsh


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## marshman (Nov 29, 2005)

Well guys I guess I am the one to blame for my issues. I mounted the motor on the boat this weekend leveled it out and let it run for about 10 minutes mid throttle...checked the oil and sure enough it was over the full line on the dip stick. I ended up removing about 8-10 ounces to get it right at the full level. 

Brought the boat / motor down to the showboat festival to be the obnoxious duck hunter ripping down the river.....she ran like a champ and never cut out a bit. I have plans to head down to the flats tonight for a crop tour and to really test it on a long run down the bad...

I have plans to replace the oil / filter with synthetic.

Another question : 

I was reading in the owners manual about lubrication, primarily the shaft and seal for the drive shaft. Has anyone had to replace their seals at the prop end of the shaft? 

I keep it greased hitting all of the ports periodically through the season but do not really know how I could tell if this seal is getting worn...I would assume that there would be grease build up from it leaking through a bad or worn seal? 

I am just trying to eliminate any issues that may effect my season. Ive only used 2 or 15 days of vacation and have a feeling that I will be sick (wink, wink) during the early parts of november....

Thanks again for all of the info!

Marsh


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## tracker14 (Jun 1, 2007)

MFPS said:


> Freeway sports us-23 and thompson road. They sell them and fix'em
> 
> Good luck follow up and let us know what it was


get your wallet out if your going there!


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## marshman (Nov 29, 2005)

Ran the boat with 3 guys and the fat pup yesterday before the shi- meeting....never missed a beat! I was pumped about that. I was not so pumped when i saw the crop conditions in some of the fields....

thanks again for all of the help. this one will be a good one to refer back to around the opener when everybody starts running their rigs!!!

~marsh


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