Briggs Vanguard 6.5 hp only runs with choke on

[Knots]

I've got an Iron & Oak 20-ton splitter with a Vanguard 6.5 hp on it. I've put a little over 50 hours on it with no problems.

Now it will only run with the choke half closed.

I theorized that the float arm had bent due to all the bouncing it experienced when I moved it on a trailer from CT to ME. I abandoned that theory after I dropped the bowl and found that the float is a one-piece molded plastic piece.

There's no metal wire holding the needle on either - it just slides into a slot on the plastic float.

Any ideas short of rebuilding the whole carb?

 

[BrotherBart]

What kind of crud was in the bowl? 99 times out of a hundred the curse of leaving ethanol gas in it for extended periods has crapped up the carb if it only runs choked .

 

[Knots]

There was a small amount of solids in the bottom. I'd guess I'd describe it as what you'd expect to see after 50 hours.

I tried to be religious about adding Sta-Bil to the gas. Recently I've just been using 100% gas in my small engines.

 

[dougand3]

The bowl bolt on most small 4 cycle carbs has 2 passages - vertical and horizontal. Run a thin wire (phone jack wire) thru them and spray with carb cleaner. Make sure the jet above this bolt is clean, too.

 

[Knots]

The bowl bolt on most small 4 cycle carbs has 2 passages - vertical and horizontal. Run a thin wire (phone jack wire) thru them and spray with carb cleaner. Make sure the jet above this bolt is clean, too.

Yeah - I read that about some of the bigger horsepower Vanguard engines. Mine appears to just have a solid bolt that holds the bowl on.

 

[dougand3]

Yeah, hard to clean the passages on that bolt! You have a fuel restriction in some passage or jet, having to choke to run. There must be a tube that dips into bowl for fuel pickup - make sure it's clean and flows. Also, get your engine # and find a carb part # - there may be an AM carb for cheap. I've rebuilt these carbs with a kit and never got engine running correctly - ended up buying AM carb. Now, chances of a good rebuild increase if you have a parts washer with carb cleaner.

 

[Knots]

Yeah, hard to clean the passages on that bolt! You have a fuel restriction in some passage or jet, having to choke to run. There must be a tube that dips into bowl for fuel pickup - make sure it's clean and flows. Also, get your engine # and find a carb part # - there may be an AM carb for cheap. I've rebuilt these carbs with a kit and never got engine running correctly - ended up buying AM carb. Now, chances of a good rebuild increase if you have a parts washer with carb cleaner.

Good advice. My weed whacker was running bad and a 20 buck AM carb fixed it right up. I must be getting old - I'm used to rebuilding everything. Heck, I remember when we used to hone brake cylinders...

 

[duramaxman05]

A good carb cleaning should do the trick. Stabil is a fuel stabilizer. It doesnt help with the ethanol issues. Unless stabil has come out with something new. I use startron and have been using it for 7 or 8 years and have not had any ethanol relate problems with any of my stuff

 

[Highbeam]

Your jet(s) are plugged. Can of carb cleaner, air compressor, and maybe a thin wire and blast out all passages you can find from bottom and top.

 

[Oldman47]

On some carbs that bowl bolt screws into a tube that has ports through it higher up in the carb. Make sure those are clean and the jet that goes out the top of that tube is clean. Be careful spraying carb cleaner, don't ask how I know.

 

[Corey]

Sounds like you have a fuel blockage somewhere. I would get some ethanol gas, or make some yourself by adding 10% heet to a tank and try running that through the system. Ethanol is excellent at dissolving varnish and all the other crud the dead dinosaurs leave behind. Though if the carb is 100% plugged, then it likely needs a mechanical cleaning and re-build.

 

[AK13]

When I had this issue it was chunks of rust getting through the fuel filter gumming things up. You are on the right track. Its definitely a fueling issue. Speaking of which I guess I'd make sure you have free flowing fuel to the carb as well.

 

[Knots]

It looks like I'll have to dig into the carb and the fuel line. No easy fix on this one. Hopefully I'll have some time on Sunday.

I've got A LOT of wood to split...

 

[maple1]

Get some Seafoam.

I used to have to take apart & clean one small engine carb or another a couple times a year - between the stuff that sits all winter & the stuff that sits all summer. Now I try running a tank or part tank of gas with Seafoam added to it first - and it's been a while since I've had a carb apart. I have a Stihl weedwhacker that I always had to have a bit of choke on to use (given to me by an in-law, sat for a couple years) - one treated tank and it works like a top. Just a month ago noticed my JD LA135 with Briggs twin in it was running rough after sitting the winter. I did the Seafoam thing & it's running like new again after one lawn mowing session - and also stopped the smoke-puff-on-startup thing it's been doing for a couple years now.

Magic juice.

(Still a chance you'll have to disassemble, if it's a piece of real dirt - but most times it's gas gum)

EDIT: Looks like some green in your float bowl - a sign of possible gas gum in a jet.

 

[Knots]

I've heard from some people that Seafoam actually works. I'll have to try it out.

The weekend was too short and work is really cramping my style this week. I haven't had a chance to monkey with it yet.

 

[Hogwildz]

A/M carbs are cheap. I got one for my Honda powered log splitter for $20.00 off ebay. Quicker to replace then dick around trying to clean every little port out after disassembly. I have done it that way and had success, but for $20,00 and the ease, the new carb was the way I decided to go last round.

 

[BrotherBart]

A/M carbs are cheap. I got one for my Honda powered log splitter for $20.00 off ebay. Quicker to replace then dick around trying to clean every little port out after disassembly. I have done it that way and had success, but for $20,00 and the ease, the new carb was the way I decided to go last round.

That is what I do. Actually cheaper than most carb kits and no messing with carb cleaner. Five minute swap and go.

 

[maple1]

Pouring some magic juice in the tank is even easier. I always try that first.

 

[Whitepine2]

I find seafoam works well but have you checked the gas tank vent sometimes it's the smallest
of things that give trouble.

 

[Fred Wright]

If you have to run it choked the carb probably needs cleaning. Like the folks say, it's easy to do. Compressed air makes the job easier yet.

Had this issue with an older Briggs opposed twin some years ago, a garden tractor freebie. Just the ticket for hauling rounds out of the woodlot. Pulled the carb apart and sprayed with cleaner then blew it out with air. Been running like new ever since.

It was an orphan, had set abandoned for lord knows how long. When I got it going I installed a shutoff valve in the fuel line. If it's gonna set for longer than a few weeks, shut off the fuel and run the carb dry.

 

[Pdesjr]

Clean the carb.Then seafoam in every time you fill your gas can.The new ethanol fuel only has a shelf life of a couple months.So don,t store a lot of fuel.Fresh is best.

 

[Ashful]

Reminds me... I need to put a little time on my splitter today.

 

[Knots]

Well, I threw it back together and put a heavy dose of Seafoam in the tank. Checked the tank vent - it was OK.

Spent a few hours splitting, but it still won't go without the choke on half. Looks like either disassembly or replacement is next.

However, I put Seafoam in the tractor too. The needle and seat had been sticking to the point that I had to drop the bowl every time I started it - even when it was only the day before. Now the needle doesn't stick anymore.

 

[maple1]

Ya, if it's a piece of solid dirt like a rust speck or grain of sand or whatever, getting physical with it will be needed. We also have a 2" water pump here with a 5hp Briggs on it, and there is a piece of steel in the internal tank structure that is rusty and will bung a carb jet up with a rust spec once in a while. Intended to get a new tank for it for a while now but just hasn't happened yet.

But for the gunky varnishy spoogey type stuff that happens when gas deteriorates, Seafoam kicks butt.

 

[Jags]

Now the needle doesn't stick anymore.

One of the properties of Seafoam is a lubricant. Probably just the ticket for your sticky needle valve.