# John Deere 116 B&S 16 twin



## bridgeendfarm

Hey Guys 

I'm beating my head on a old JD 116, that I have. the old green tank runs well for a while now about 15 minutes mows good then it starts fuel starving almost like a vapor lock. I rerouted the fuel lines away from the mower but it hasn't seemed to improve it. It has an electric pump (have no idea the psi) and it also has a diaphram type pump in front of the carb. I figured the electric pump went bad so I bought a little 12v 2 psi one but it seems to dump to much fuel for it starts dripping out of the front diaphram.
Even with it hooked up and energized it seems to do the same thing. I hate to retire the old boy for it has been a great mower with real steel. Any advise would be appreaciated. 
It has slowly gotten worst over the last few years and one good thing is I get plenty of breaks mowing my yard. 
thanks Bob


----------



## jdfrederick

I have exactly the same problem with the same mower. I bought a new gas line from the electric fuel pump under the battery and new pulse fuel pump rebuilt kit and of course fuel filter. Still does the same thing. Perhaps the fuel line from the tank to the electric fuel pump is bad?? Or the electric fuel pump itself? When I crank the engine with the line unhooked, it does not look like it's pumping gas. After about 20 mins, the fuel filter is empty. In 15 mins of sitting, it fills back up again. I cannot figure it out. Any ideas????


----------



## chuck_thehammer

I would start with the gas cap...if the vent in the cap is plugged NO GAS will flow after 10 to 20 minutes...when the engine stops remove the cap and see if it will restart...as far as the electric fuel pump...if the carb float is not in the best of shape or the needle and seat are warn or damaged it will not be able to deal with the higher pressure from the pump.


----------



## wdplucas

*JD 116 with same motor and similar problems*

Hello Gentlemen,

I happen to have a JD 116 that is starved for fuel on the High speed circut.
The symptoms are exactly like described above. When cold the motor starts and runs great. Then all of a sudden with no rhyme or reason the motor shuts down like someone shut off the key. While playing with this symptom I realized that if I put the throttle down to idle, the motor will stay running perfect, but as soon as I bring the lever up past 1/2 way the motor dies. 
I can keep it running with a full choke every 1-2 seconds at wide open, but know the motor isn't designed to run this way. I have tested full throttle with starting fluid and the motor takes off instantly. Leading me to believe this is a fuel issue. I've torn down cleaned and reassembled the carb. Cleaner tips through HS, LS, venturi and any other orifices I could find. I also used carb cleaner spray and dried entire unit with clean compressed air.

The HS jet is fixed (non adjustable) but is clean as a whistle. I'm getting plenty of fuel to the carb as it primes the bowl in less than 3 seconds.

The tractor is my grandfathers and I'm trying to fix it without throwing a ton of money at it.
Other fixes I've tried are gas cap vent cleaning (and removal), fuel filter cleaned, (and removed for now)

If it were a pump issue I'd assume it wouldn't prime the bowl so fast. 
(unless a slightly torn diaphram would allow for flow at low pressure, but lack ability to build high enough pressure to feed the HS circuit.

Any suggestions would be appreciated. I've been a mechanic my whole life but this one is has me stumped.

Thanks

Luke


----------



## 30yearTech

What brand and model of engine is on your mower?


----------



## wdplucas

*john deere B&S 16 hp twin*

Sorry i guess i assumed that the title of this thread being john deere 116 b&s 16 hp twin
That anyone reading the post would have known that.

I've located the problem:
This tractor uses a vacuum circut to control the fuel pump. Theres a tiny vacuum valve under the air cleaner which seems to be bad. If I unplug the vac lines from this valve the problem is gone.

Unfortunately this part is no longer available from john deere.

Im on my mobile phone but will post a link from jdpc showing the assembly and ill identify the faulty vacuum valve

Thanks


----------



## 30yearTech

wdplucas said:


> Sorry i guess i assumed that the title of this thread being john deere 116 b&s 16 hp twin
> That anyone reading the post would have known that.
> 
> I've located the problem:
> This tractor uses a vacuum circut to control the fuel pump. Theres a tiny vacuum valve under the air cleaner which seems to be bad. If I unplug the vac lines from this valve the problem is gone.
> 
> Unfortunately this part is no longer available from john deere.
> 
> Im on my mobile phone but will post a link from jdpc showing the assembly and ill identify the faulty vacuum valve
> 
> Thanks


Do you have any clue to how many different variations of 16 hp engines Briggs and Statton made???

Model type and code numbers tell everything about an engine, how it's equipped etc. --> (vacuum valve).

So yes, I read the post and knew it was a 16 hp Briggs, since you still have not posted the numbers, we don't know which Briggs it is.

The part may be exclusive to JD, with the numbers off the engine we can tell.

Glad you got it figured out.


----------



## wdplucas

*JD 116 16hp B&S mower*

Hello Gentlemen,

I appreciate all your prompt responses. I've finally had some more time to dig deeper into my tractor that is now running, but not as well as it could.

Please find link:
http://jdpc.deere.com/jdpc/servlet/com.deere.u90490.partscatalog.view.servlets.HomePageServlet_Alt

Expand the drawing out and find part #8 described as "AM39009 VALVE 1 - 315000 (VACUUM) 

Item 10 simply fastens the unit to the air cleaner. I have had it off, cleaned with parts solvent and dried with compressed air.

When reinstalled same symptom:
can connect 1 of the 2 hoses marked 17 on the drawing, but as soon as I hook up both the motor dies from full throttle. If I unplug the vacuum hose the engine will recover and continue to run.

right now I'm bypassing this "vacuum valve" while still running the vacuum lines through the air cleaner.

However the motor seems to bog under load (slightly) and smells sometimes to be running rich.

All the electrical connections on item 22 have been cleaned and tested with an ohm meter. Seem to be fine.

Also finally I have the serial numbers of the tractor and motor:

Product Identification Number
*M00116C292609
116H Lawn Tractor/970H

Briggs & Stratton Corp.
Model Type Code
402707 0131 01 84030712

Thanks for any and all thoughts, I've been told item #8 is discontinued from the Deere deeler in town.



Luke


----------



## duffer72

FYI that is a briggs p/n 395379 also NLA


----------



## wdplucas

Ok, is there any way to bypass or replace the system?


----------



## duffer72

try giving briggs call and see if they have any suggestions 1-800-444-7774


----------



## wdplucas

Ok, is there any way to bypass or replace the system?


----------



## duffer72

I'm not familiar with that system, but they should be able to assist you on it.


----------



## jdfrederick

*Continuing John Deere 116 problems*

Does anybody know where the fuel line runs in the back of the tractor from the tank to the electric fuel pump under the battery? I've replaced the rest of the fuel line and that has not solved my problem of no fuel in about 15 minutes. Also replaced the front fuel pump on the front of the carb to no avail. I cannot see the rear part of the fuel line so I assume I'll have to run the tractor up on ramps.
Could this be a float issue or a float needle issue? It runs 20 mins, then the fuel filter is empty and it stops. In 30 minutes, it is ready to go again. I'm mystified. Jerry


----------



## duffer72

Sounds like one of three things, crap in the tank plugging up the outlet, bad fuel cap (not Venting) or you are getting a vapoer lock in the fuel line. When it dies what happens if you take the ful line loose from the filter, do you get any flow out of it?


----------



## wdplucas

*john deere 116*

I cant answer your question directly, but I can offer an option to figure out if the problem is before or after your electric fuel pump:
Use a container with a hose barb the size of your fuel line. Fill the container with a quart of gas and connect the container to your fuel line before the electric pump under the battery.

Run the tractor for your problematic time and monitor the quart container for flow. If the problem continue the fuel system from there back to tank shoud be good.

Next I'd try connecting the diagnostic tank infront of the electric pump. Ensure the container remaines higher than your diaphram pump on the front of the carb.

Monitor the fuel level in the diagnostic tank, if problem continue try connecting the diagnostic tank directly to the carb pump inlet.

If problem continues I'd try disconnecting your vacuum lines running to the pump on the front of your carb, if problem goes away the vacuum system has a faulty valve block.

One last thing try running the machine at idle when the problems arise.


----------



## jdfrederick

*JD 116 fuel problem*

I am having exactly the same problem with mine. Replaced the fuel line from the electric pump under the battery all the way up to the pulse pump on the front of the carb. No help. Then I got under the tractor with the deck off, and found the fuel line from the tank to the bottom of the electric pump. There is a rubber grommet then a shut-off valve which comes out of the front of the tank, onto which the fuel line is connected with a clamp. I wiggled the grommet and gas leaked out. Yes! I thought! This is it. I took the grommet out and it was cracked (indicating the pumps were sucking air) and got a replacement. ($2.40 at the JD dealer, in stock.) The grommet also had a little mesh bag which apparently functioned as a filter, which was packed with gunk. I thought sure that replacing this grommet would do the trick. Nope.
But it might for you! I'm now going to try some more tricks to find out exactly where the blockage is. Good luck. I'll let you know when I finally get this old tank fixed.


----------



## jdfrederick

This has been really helpful; I'm making some progress at narrowing down where the problem is. I thought it was a cracked gromet coming out of the front of the fuel tank where the shut off valve is (Why on earth would they put it there?). But replacing that, and a new fuel filter did not help at all. I just about have it narrowed down to the electric fuel pump under the battery WHICH APPARENTLY IS NOT MADE ANYMORE! Does anybody have any idea where I might look for this piece? it is part number AM38788. Jerry


----------



## 1kelley1

jdfrederick said:


> This has been really helpful; I'm making some progress at narrowing down where the problem is. I thought it was a cracked gromet coming out of the front of the fuel tank where the shut off valve is (Why on earth would they put it there?). But replacing that, and a new fuel filter did not help at all. I just about have it narrowed down to the electric fuel pump under the battery WHICH APPARENTLY IS NOT MADE ANYMORE! Does anybody have any idea where I might look for this piece? it is part number AM38788. Jerry


You can buy a cheap diaphragm fuel pump at any auto parts store. Mount it anywhere it's handy. Make sure it's grounded and wired on/off with the key switch. Good time to replace all the 1/4" fuel line, too.


----------

