Vacuum problems B10 fuel delivery

[Vagabond]

The B10 has been giving me trouble, where it will suddenly quit on me for no apparent reason.   I chased the fuel flow up from the carburetor using a line clamp as I went.  I found that there was extremely restricted flow from the fuel tank.  Removed the tank and almost nothing coming out (it's full). Removed the cap to pour the gas into a separate container, and viola!  The gas came pouring out of the line. 

The gas cap is not original, and does not properly thread onto the fuel tank.  The inside top of the cap is allowed to seat on the rim of the fuel tank filler throat.  Once removed there is ample flow.  So I rigged the cap so that it could not seat.

Now the machine will not idle.  It wants to run at a very high rpm even when throttle is at idle position and choke wide open.  I went back through and reset the carburetor jets to 1.5 turns each.  Not much help and getting surging and erratic rpm's.  I know the carb needs a rebuild.  It leaks like crazy,  somewhat less while running.  In fact, it ran much better, even good, when there was excessive vacuum in the fuel system (until it would quit).

How critical is the cap itself, as far as metering the vacuum.  Is it made to an exacting standard?  Nothwithstanding the issues with the carb, which probably include float bowl needle/seat deterioration, might I get a big difference once I replace the cap with the proper one?

Any insight would be appreciated!

[theniteowl]

I do not know that the fuel cap actually metered the fuel flow, just allowed air to pull into the tank as fuel was consumed.  The carb was likely adjusted to it's best operating condition while slightly starved for fuel so not working at optimum but better than now when it is getting plenty.  

Give the carb a good cleaning, check the condition of seat and needle replacing if needed.  Check your float level setting, adjust the governor and the carb again.  The carbs are pretty easy to adjust, the only issues I have had were with sticking floats or needles or a float that was out of adjustment.  On some of my tractors the float needs to be higher or lower than others and it is a nuisance to take them apart repeatedly to make minor corrections but it eventually pays off.

[Vagabond]

Thanks Trent.  I'll get a proper gas cap too, and probably order a cheap carb to use while I fix this one.  It's leaking out of every hole and then some.  The throttle shaft is loose as well.   After running a heavy mix of Seafoam through it a few weeks ago, it started leaking even worse, which I didn't believe was possible!

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[theniteowl]

I have a similar issue on one of my B112s, the throttle shaft is a little sloppy and blowing out fuel.  I expect it sucks in air as well affecting compression a bit.  Have not yet figured out what parts to use to rebuild it but she is running decently enough at the moment.  I think the throttle shaft is available but I might have to drill out the carb body and put in a bushing.  Not sure what people use for these, if there is a standard size to go to or what.

If your needle is not seeting all the way you will get gas leaking out the bottom of the carb.

That reminds me, have to pick up some new fuel line.  This one is dry rotted and starting to leak.  Have to shut it off at the tank when I park.

Then I just need to find a slightly larger snow blower.  The front wheels are wider than the snow blower and they keep getting caught in the heavy stuff pulling the wheels sideways.  Did a nice job throwing that thick layer of powder we got yesterday though.  How do you measure how far the snow throws?  You can count how far out it goes from the tractor but do you also count how far it blows back to get you in the face when the wind shifts?  I looked like a snowman with all that powder stuck to me.

 

[Vagabond]

Haha!  Well, one way to measure the snow throw distance is to have someone run along side the tractor holding the dumb end of a long tape measure, while you clamp the smart end to the tractor.  As your assistant runs away from the arc of snow, or chases it back towards you, you can read the measurements, then just average it all once done. :-)

I have seen the shaft rebuild kit, but can't remember where.  Not sure how it's done.  I don't understand why the leaky shaft would affect compression.  I would have thought just the air/fuel mixture.  Can you enlighten me?

I puzzled for a good while last night over the vented cap issue.  I tried like crazy to find a definitive write up on the topic, to no avail.  I decided to check the vent on the cap, and discovered that this was a cap for a two stroke engine.  When I blew through the cap, it was very restricted, so I cleaned it out, and it was still very restricted.  The thing is, I don't believe there is anything wrong with it.  It has a rubber grommet that is vented down the middle, and might have been taken off of an implement designed to be handheld, and inverted at times, and so had to be very tight.

So, long story short, I pulled the rubber grommet out, and put the cap back on tight, and you know what?  The thing started right up and ran like a champ!   It needs a little tweaking at idle still, but it ran better than ever, and I was able to plow out the mailboxes and ends of the driveway without anything but smooth even power delivery.

Anyway, I still wonder if there is something to the cap vent being of a limited size.  If I take the cap all the way off, fuel flows like crazy.  If threaded on half way, the flow lessens. When just the vent is breathing, the flow is less still.  Maybe a good, tight carb, can handle extra flow, but a worn one loses it?

Well, I just ordered a cheapy carb.  I sure hope it works.  Now I can take my time with the B&S carb.  Fixing the throttle shaft might be interesting, but replacing the top half is tempting.

One of your B-112's, eh?  Must be nice. I'd get clobbered if I brought one more man-thing home!  Maybe if I sold some of my audio stuff, she'd cut me some slack...

 

 

 

[Missouri Blacksmith]

2 hours ago, Vagabond said:

Haha!  Well, one way to measure the snow throw distance is to have someone run along side the tractor holding the dumb end of a long tape measure, while you clamp the smart end to the tractor.  As your assistant runs away from the arc of snow, or chases it back towards you, you can read the measurements, then just average it all once done. :-)

I have seen the shaft rebuild kit, but can't remember where.  Not sure how it's done.  I don't understand why the leaky shaft would affect compression.  I would have thought just the air/fuel mixture.  Can you enlighten me?

I puzzled for a good while last night over the vented cap issue.  I tried like crazy to find a definitive write up on the topic, to no avail.  I decided to check the vent on the cap, and discovered that this was a cap for a two stroke engine.  When I blew through the cap, it was very restricted, so I cleaned it out, and it was still very restricted.  The thing is, I don't believe there is anything wrong with it.  It has a rubber grommet that is vented down the middle, and might have been taken off of an implement designed to be handheld, and inverted at times, and so had to be very tight.

So, long story short, I pulled the rubber grommet out, and put the cap back on tight, and you know what?  The thing started right up and ran like a champ!   It needs a little tweaking at idle still, but it ran better than ever, and I was able to plow out the mailboxes and ends of the driveway without anything but smooth even power delivery.

Anyway, I still wonder if there is something to the cap vent being of a limited size.  If I take the cap all the way off, fuel flows like crazy.  If threaded on half way, the flow lessens. When just the vent is breathing, the flow is less still.  Maybe a good, tight carb, can handle extra flow, but a worn one loses it?

Well, I just ordered a cheapy carb.  I sure hope it works.  Now I can take my time with the B&S carb.  Fixing the throttle shaft might be interesting, but replacing the top half is tempting.

One of your B-112's, eh?  Must be nice. I'd get clobbered if I brought one more man-thing home!  Maybe if I sold some of my audio stuff, she'd cut me some slack...

 

 

 

Its better to ask for forgiveness than ask for permission 

[Vagabond]

21 minutes ago, Missouri Blacksmith said:

Its better to ask for forgiveness than ask for permission 

There is wisdom in your words oh wise one... 

[Vagabond]

4 hours ago, theniteowl said:

Have not yet figured out what parts to use to rebuild it but she is running decently enough at the moment.  I think the throttle shaft is available but I might have to drill out the carb body and put in a bushing.  Not sure what people use for these, if there is a standard size to go to or what.

Trent, isn't it possible that it's just the shaft that's worn?  A new one is short money, and I'm inclined to order one and see.  I could always order the bushing if it's still required. What do you think?

[RayS]

The upper carburetor body is still available from Briggs. They sure went up in price in the last few years. $30 last time I checked.

Part number is 391034 and is $72 now. There is one in the link below on ebay much cheaper. The part number changes to 299098 if you have the following type No(S).

0010, 0131, 0137, 0150, 0152, 0165, 0201 and 0510. This number is $75

http://www.ebay.com/itm/Briggs-Stratton-391034-/252751988713?hash=item3ad93147e9:g:xnEAAOSwgQ9VnZds

The throttle shaft bushing is part number 691769 and is cheap. The throttle shaft is part number 691944.

http://www.ebay.com/sch/i.html?_odkw=briggs+299098&_osacat=159912&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.Xbriggs+691769.TRS0&_nkw=briggs+691769&_sacat=159912

The picture below explains the process of changing the bushings in a two piece flow jet carburetor. Hope this helps.

[theniteowl]

On 2/10/2017 at 5:39 PM, Vagabond said:

Haha!  Well, one way to measure the snow throw distance is to have someone run along side the tractor holding the dumb end of a long tape measure, while you clamp the smart end to the tractor.  As your assistant runs away from the arc of snow, or chases it back towards you, you can read the measurements, then just average it all once done. :-)

I have seen the shaft rebuild kit, but can't remember where.  Not sure how it's done.  I don't understand why the leaky shaft would affect compression.  I would have thought just the air/fuel mixture.  Can you enlighten me?

I puzzled for a good while last night over the vented cap issue.  I tried like crazy to find a definitive write up on the topic, to no avail.  I decided to check the vent on the cap, and discovered that this was a cap for a two stroke engine.  When I blew through the cap, it was very restricted, so I cleaned it out, and it was still very restricted.  The thing is, I don't believe there is anything wrong with it.  It has a rubber grommet that is vented down the middle, and might have been taken off of an implement designed to be handheld, and inverted at times, and so had to be very tight.

So, long story short, I pulled the rubber grommet out, and put the cap back on tight, and you know what?  The thing started right up and ran like a champ!   It needs a little tweaking at idle still, but it ran better than ever, and I was able to plow out the mailboxes and ends of the driveway without anything but smooth even power delivery.

Anyway, I still wonder if there is something to the cap vent being of a limited size.  If I take the cap all the way off, fuel flows like crazy.  If threaded on half way, the flow lessens. When just the vent is breathing, the flow is less still.  Maybe a good, tight carb, can handle extra flow, but a worn one loses it?

Well, I just ordered a cheapy carb.  I sure hope it works.  Now I can take my time with the B&S carb.  Fixing the throttle shaft might be interesting, but replacing the top half is tempting.

One of your B-112's, eh?  Must be nice. I'd get clobbered if I brought one more man-thing home!  Maybe if I sold some of my audio stuff, she'd cut me some slack...

 

The air hole in the cap has to allow enough air through for fuel to flow adequately but I doubt it has anything to do with regulating the flow otherwise.  The carb regulates itself with the float and needle.  If the carb leaks excess fuel then there is an issue in the carb.

Air blows out through throttle shaft hole blowing out fuel on one stroke of the engine so I imagine it is sucking air in through the same hole on the opposite stroke which lessens the air drafted out of the carb and may screw up the air/fuel mix.  At the very least it can suck dust into the engine.

If I remember correctly, my carb did not have a bushing for the throttle shaft and would have to be drilled out to put one in.  I have not put any real effort into looking into it yet as the tractor is running pretty well as is and if needed I can grab a carb from one of my Landlords.  One of my 101 engines is apart in my shop and the other blew last winter when something hit the quick connect oil change gizmo on the side of the engine while my wife was plowing causing all the oil to leak out into the deep snow where it was not noticed.

The one B112 is the one I had to put the Variable transmission into and is currently running my snow blower.  The other B112 is doing plow duty.  My one running Landlord is at the house I am working on.
My wife loves my tractors.  She needs her tractor therapy time  just like me.

 

Edited February 13, 2017 by theniteowl

[theniteowl]

Thanks for the info Ray.

My engine looks to be type 0127.  Looks more like 0327 but could not find a listing for that so figure it is just a hard to read stamp.

Will have to check the carb again but do not believe it had a bushing.
This must be an early release B112 as it has a start button rather than using the key like my other B112.  No idea if the carb is original though it seems to be the correct type.  Same parts should work for Vagabond and me.

[Vagabond]

5 hours ago, theniteowl said:

The air hole in the cap has to allow enough air through for fuel to flow adequately but I doubt it has anything to do with regulating the flow otherwise.  The carb regulates itself with the float and needle.  If the carb leaks excess fuel then there is an issue in the carb.

Air blows out through throttle shaft hole blowing out fuel on one stroke of the engine so I imagine it is sucking air in through the same hole on the opposite stroke which lessens the air drafted out of the carb and may screw up the air/fuel mix.  At the very least it can suck dust into the engine.

If I remember correctly, my carb did not have a bushing for the throttle shaft and would have to be drilled out to put one in.  I have not put any real effort into looking into it yet as the tractor is running pretty well as is and if needed I can grab a carb from one of my Landlords.  One of my 101 engines is apart in my shop and the other blew last winter when something hit the quick connect oil change gizmo on the side of the engine while my wife was plowing causing all the oil to leak out into the deep snow where it was not noticed.

The one B112 is the one I had to put the Variable transmission into and is currently running my snow blower.  The other B112 is doing plow duty.  My one running Landlord is at the house I am working on.
My wife loves my tractors.  She needs her tractor therapy time  just like me.

 

Thanks for the pile of info on the carb Trent.  So are you saying that the carb housing always wears along with the throttle shaft?  I guess it makes sense seeing as it's aluminum.  I guess it's just wishful thinking, hoping to get away with just a new throttle shaft assembly. g

I had a 1958 Volvo PV-444 years ago.  I traded a '66 Plymouth Belvedere for it.  I loved that old Volvo.  I fixed it all up, and put a giant stereo in it.  On my first cruise down Rte 111, I was enjoying the drive and the over-cranked stereo, just jammin' along, when the very loud music was eclipsed by a very, VERY loud KNOCK, KNOCK, KNOCK!  Well, would you believe it, these old Volvo's had the oil line connected to the oil guage reading pressure at the dial, and this one, for whatever reason, had not been fully tightened.  Soooo.... It was 'So Long' Volvo!  Our time was short but sweet!  And lesson learned on music volume when taking a first drive!  I think I might have had a chance at catching it if I could have heard the first complaints of the tappets.

[Vagabond]

5 hours ago, theniteowl said:

The air hole in the cap has to allow enough air through for fuel to flow adequately but I doubt it has anything to do with regulating the flow otherwise.  The carb regulates itself with the float and needle.  If the carb leaks excess fuel then there is an issue in the carb.

Air blows out through throttle shaft hole blowing out fuel on one stroke of the engine so I imagine it is sucking air in through the same hole on the opposite stroke which lessens the air drafted out of the carb and may screw up the air/fuel mix.  At the very least it can suck dust into the engine.

If I remember correctly, my carb did not have a bushing for the throttle shaft and would have to be drilled out to put one in.  I have not put any real effort into looking into it yet as the tractor is running pretty well as is and if needed I can grab a carb from one of my Landlords.  One of my 101 engines is apart in my shop and the other blew last winter when something hit the quick connect oil change gizmo on the side of the engine while my wife was plowing causing all the oil to leak out into the deep snow where it was not noticed.

The one B112 is the one I had to put the Variable transmission into and is currently running my snow blower.  The other B112 is doing plow duty.  My one running Landlord is at the house I am working on.
My wife loves my tractors.  She needs her tractor therapy time  just like me.

 

Thanks for the pile of info on the carb Trent.  So are you saying that the carb housing always wears along with the throttle shaft?  I guess it makes sense seeing as it's aluminum.  I guess it's just wishful thinking, hoping to get away with just a new throttle shaft assembly. g

I had a 1958 Volvo PV-444 years ago.  I traded a '66 Plymouth Belvedere for it.  I loved that old Volvo.  I fixed it all up, and put a giant stereo in it.  On my first cruise down Rte 111, I was enjoying the drive and the over-cranked stereo, just jammin' along, when the very loud music was eclipsed by a very, VERY loud KNOCK, KNOCK, KNOCK!  Well, would you believe it, these old Volvo's had the oil line connected to the oil guage reading pressure at the dial, and this one, for whatever reason, had not been fully tightened.  Soooo.... It was 'So Long' Volvo!  Our time was short but sweet!  And lesson learned on music volume when taking a first drive!  I think I might have had a chance at catching it if I could have heard the first complaints of the tappets.

[Vagabond]

Thanks for the instructions and info, Ray.  I completely missed that post earlier.  I'll have to look closer at my carb.  I didn't think it had a bushing and like Trent, will be looking for a 'how to' on how to drill out for installation.

[Vagabond]

Trent, if your snowblower is too narrow for the tractor, could you bolt on a couple of short wings angled back?  Would only have to be 3 inches each. Three bolts to fix to the snowblower housing at the forward edge, and a  bracket from the back, fixing the wings at 45 degrees or so.

Edited February 14, 2017 by Vagabond

[theniteowl]

I would think the aluminum casting would wear before any brass insert and is why they added them but apparently not before our carbs were made.  Unless the inserts are purely for rebuild purposes and not there originally.  Mine actively spits gas out the outside end of the carb through that worn hole but I do not know if it is the shaft, the hole through the carb body or both that are worn.  She still runs pretty well.  Does a little bit of mild surging at full throttle when good and warm but idles nice.  Blows the slightest bit of smoke when first started as well but only for a couple seconds.  I figure it can wait for warmer weather.

I could mount some wings to pull the snow in, that is a good thought.  It would mean I would have to slow down a little bit when the volume of snow is higher but this is the variable drive tractor so that is not a problem.  Would help on those occasions when I want to push a small amount of snow without the blower running during final cleanup.  Should mount something on my plow as well that can be lifted during normal use and dropped when just scraping up the leftovers.

I have a couple other snow blowers though, got to check and see if any are larger.  It would be nice to do the sidewalk in a single pass rather than two but it is just a little too narrow.

If I ever get it home and hooked up I have a 52" blower for my Wheel Horse.  I really want to see that in use at least once before I have to sell.

[Vagabond]

If you were to mount wings on the snowblower with a brace behind, the brace could be extendable, and the wings designed to be flipped such that in deeper snow, they are swept back, but in light snow they could be swept forward.

I hear what you're saying on the throttle shaft.  In pictures, I see some of the replacement shafts appear to have an aluminum looking finish at the ends. Do you know what's with that?

A 52 inch snowblower?  I can see why you'd want to bring that puppy home! :-D

[theniteowl]

I have not paid much attention to the finish on the throttle shafts, it could be a change in materials used or they may have coated it with zinc to prevent rusting.

I have a  Wheel Horse D-160 with a front end loader.  Put a ton of work into it but have only used it for the loader so far.  I came across a deal for the 52" blower, 4 foot plow, snow cab, rear PTO assembly, large mower deck which I have not measured and tire chains all for $300.  Everything is in great shape but some of the vinyl on the snow cab which I will eventually need to work on but I have not had the opportunity to try any of it out as the tractor is at the house I am working on about 30 minutes away.
Taking the loader off to put on any other accessories will be a nuisance but I have to try out that snow blower at least once.

[Vagabond]

Sounds like a nice kit.  Nice to have the FEL.  I sure could use one here to lift fresh compost over the fence around the garden and into the raised beds.  Once and a while a deal comes along, and one day I'll be flush enough to snap it up.

On those throttle shafts, the coating is only on the ends that pass through the housing.  I'm guessing to prevent galvanic corrosion?

Still have to wonder if that coating takes up enough space to give the new shaft a 'snugger' fit allowing replacement without installing a bushing.

Just got my new cheapy carb this afternoon.  There is slop in that throttle shaft as well.  I little bit is normal?

Will let you know how the rebuild of the Briggs carb goes.  I'm just going to try to replace the throttle shaft in it and see if the bushing is really needed.