Help with B&S

[Stephen in SOKY]

Hey folks, I need some help: 18 hp B&S Vanguard OHV. It's missing, coughing, backfiring and drawing crankcase oil up into the air filter. Seems worse when operating on an incline, perhaps worse under load. No smoke of any color except when backfiring/coughing.

I've put half a can of carb cleaner through it. Opened the carb, floats good, more carb cleaner in while open.

Started it, ran okay then the governor started surging the motor, eventually died.

I only run premium, fresh to me gas.

What's next???????

[agmantoo]

Stephen in SOKY
The rocker arm on the OHV engine has backed off and you have too much clearance between the rocker arm and the valve. I do not know the spec for the clearance but do not expect it to be like a car. Just snug up the adjustment until the engine starts running properly. When operating properly there is a LOT of clearance still in the rocker arm to valve setting.

[Stephen in SOKY]

I found one rocker arm that was loose on the rod. I've been adjusting, but don't seem to be getting anywhere. Any other advice? Thanks

[agmantoo]

Is this a 2 cylinder engine? If so, you may have to change the sparkplug on the cylinder with the too loose rocker arm. Stephen, either too loose or too snug and the engine will run terribly.

[Stephen in SOKY]

Thanks again. I decided it was best to take a break and work on the darned thing tomorrow. I appreciate the help.

[HermitJohn]

Adjusting valves on small OHV engines is just like adjusting valves on old car OHV engines that had solid lifters. In other words with piston top dead center and both valves closed, you then use a feeler gauge to get proper gap. No I dont have settings for your engine, but any modern small engine manual should have them or probably on web someplace. Its no great manufacturers secret. Sure its just as overlooked on small engines as it was on last of the automotive engines with solid lifters.

Here is a link to a Briggs check chart that has the specifications for adjustments on their engines.

http://www4.briggsandstratton.com/mi...art_ms3992.pdf

Here is a link with some basic information on setting valves.

How are the valves properly serviced? (http://faqs.custhelp.com/cgi-bin/faq...i=&p_topview=1)

Here is quote of specific info on adjusting the OHV B/S valves from above link minus the diagrams:

Adjusting Overhead Valves

Release the brake spring. Then, turn the flywheel to close both valves.

Insert a narrow screwdriver into the spark plug hole and touch the piston. Turn the flywheel clockwise past top dead center until the piston has moved down 1/4". Use the screwdriver to gauge the piston's range of motion (image F). PLEASE NOTE: This procedure must be performed for each cylinder on V-Twin engines.

Check the valve clearance by placing a feeler gauge between the valve head and the rocker arm (image G). Clearances differ for the two valves and typically range from .002 - .004" to .005 - .007". Valve clearance specifications for your engine series are available by viewing our Engine Specifications Chart (pdf).

Adjust the clearances as required by turning the rocker screw. Once adjustments are completed, tighten the rocker nut.

Install the valve cover, using new gaskets, as required, and make sure the cover is secure.

[Stephen in SOKY]

Thanks again for the help. I decided to set them all, so I pulled the gas tank & breather housing, set all to .004 as both my owners manual & the website said .004-.006, fired it up and it was VERY loud and lacked power. Next I pulled everything again, put in 2 new properly gapped plugs, set valves to
.005, new air filter and fired it up. Sounded great til I loaded it.

Both times I've set valves I've used a screwdriver to establish top dead center (When the piston is the furthest out, correct?) then continued on until it recedes by 1/4 inch per a caliper, carefully set clearance with feeler guage, maintaned clearance while tightening lock nut & rechecked to be sure of clearance.

Assuming you agree with the methods above, should I try .006 or give up and take it to the shop?

[Wis Bang]

Originally Posted by Stephen in SOKY

Thanks again for the help. I decided to set them all, so I pulled the gas tank & breather housing, set all to .004 as both my owners manual & the website said .004-.006, fired it up and it was VERY loud and lacked power. Next I pulled everything again, put in 2 new properly gapped plugs, set valves to
.005, new air filter and fired it up. Sounded great til I loaded it.

Both times I've set valves I've used a screwdriver to establish top dead center (When the piston is the furthest out, correct?) then continued on until it recedes by 1/4 inch per a caliper, carefully set clearance with feeler guage, maintaned clearance while tightening lock nut & rechecked to be sure of clearance.

Assuming you agree with the methods above, should I try .006 or give up and take it to the shop?

Too tight will rob the power...tight vales will burn too!

Daddy always said if you can hear 'em clatter, you won't burn 'em! Go out to .006...

[agmantoo]

What you are experiencing was what I was eluding to in my original post. When I set the clearance to what clearance was given it ran like carp. When I increased the clearance the engine ran fair. IMO the engines are a POS and the less exposure I have to them the better off I am. The valve setting will not remain set unless you do something to lock the settings. It is a poorly designed engine regardless. I do not plan on ever buying another one of these engines! B & S is obviously a company run by CPA's these days. Honda will eat their lunch eventually and management will stand around the water cooler and wonder where they went wrong!

[Stephen in SOKY]

Agmantoo, since yours ran better, not great but better on the loose side I think I'll open them up to .006 tomorrow. I assume anything beyond that would be risky?

[agmantoo]

Stephen, I doubt if you will see a change with it at .006. How loose was the rocker when you first found it loose? I have seen one of these engines with the rocker completely off the valve. I doubt that you will do any damage and the engines are noisy so the clatter will go unnoticed. I think the valves have a problem seating when the clearance is set according to the specs. Maybe there is carbon built up on the valve stems. I am only guessing but I do know you have a problem that I do not have an answer for. Keep us updated on your progress.

[millerized]

Make sure you're just tightening and loosening the valve nuts and not the entire stud. The mower I just bought/sold had a 18.5 Intek, and the while the guy thought he was loosening and tightening the nut, he'd backed the entire shaft out almost 1/2 a turn.
Also, SeaFoam and Techron are your friends for degunking carbs on the motor, and B-12 when they're off (not the vitamin, the carb dunk).
Lastly, check the crank key under the flywheel. It doesn't take much of a shear to get them running like crap.

This is, of course, barring major problems inside the motor.

[Stephen in SOKY]

I'm getting closer to a re-power on this mower. Went by the Grasshopper dealer this morning and quickly decided that I won't be trading for a new one. Does anyone have a source they've been pleased with for buying replacement engines? Will I have trouble going from a Briggs to a Kohler or will the correct Kohler just bolt up? Thanks

[millerized]

Can't help you there. I've always repaired, never replaced. There are an aweful lot of motors on ebay, and if you find one local you'll save a crapload on shipping from somethere. Can't even help you on bolt spacing or pattern. I do know that some frames (the crapsman I just sold for one) have an aweful lot of holes under the motor, some were close, but some were way off. Has to be for other size motors, if not manufacturers.

Best of luck.

[HermitJohn]

8hp and under pretty interchangable. Larger hp small engines maybe interchangable, maybe not. Shaft size, length, and bolt pattern main things but also will the decorative sheet metal/plastic fit over replacement engine? Is exhaust routing compatible? Unless you find somebody that did same repowering you want to do, you are on your own, get out your tape measure. Any simular size engine to original can be adapted in nearly anything, but how much work/modification it will take is another question.

I vaguely remember running across some website dealing with repowering lawn/garden tractors, especially older tractors where original style engines not available or else they wanted more power. Do a google, maybe you will find it. They may have some ideas on whether what you want to do will be easy or not. And if Kohler isnt easy maybe one of the Japanese brands is, you just have to do your measuring and research.

[raymilosh]

On getting a new engine. I had a B&S on a tiller that gave me fits. I found a new Honda engine at Northern Tool and Equipment (in NC) for $200. It was cheaper and easier than rebuilding the POS I had already rebuilt once before. the Honda engines have a great and well deserved reputation for being more tolerant of overwintering, being left in the rain and continuing to run fine than either B&S or Tecumseh. They're also light, quiet and cheap. Hard to beat.
Oh and bolt patterns and shaft lengths and sizes were all pretty standardized, so it was easy to find a replacement that fit.

BTW I had similar problems with smaller B&S engines. I eventually gave up after completely tearing it down a few times and sent it to the local repair shop. I forget what the problem was specifically, but it had to do with the carburator and it was easy and cheap to fix. I know, not very helpful, but that't all i remember.

[HermitJohn]

Truth is majority of people really abuse small engines, do no maintenance beyond filling them with oil/gas and seem happy if they last 2 or 3 years. Some I know would just buy a new cheap push mower every year rather than hassle with maintenance. Even the cheap American flat head engines were fairly simple and robust design and would last 10+ years if you took care of them with regular oil changes and tune ups. The smaller OHV American engines not so good, seen them give up ghost fairly early. Seen bunch of them with rod knock and rods poking through side of block. Bigger OHV American riding mower and garden tractor engines I couldnt say, never owned one and havent worked on that many. Guess I will learn some as I do have a 13hp B/S Intek brand new made for a snowblower that I got much cheaper than same size Chinese Honda clone. Must be real quality engine if selling cheaper than Honda clone, huh??? Part of reason it was cheap was its a snow blower engine and I bought it in summer. Somebody had it, didnt use it, and wanted it out of the way. Need to put real air filter on it (snow blower version of these engines didnt have an air filter, just plastic baffle) and will use it to power one of my old Gravelies. Anyway will see how it holds up with maintenence. If it lasts at least 5 years it will have paid for itself. Starts and runs ok, not really any more vibration than Honda, so ????

[HermitJohn]

Been reading more about Briggs OHV. Apparently Intek is the cheapo consumer level OHV engine line. They are not looked on highly except by those trying to hype and sell them... Nobody would consider trying to rebuild one, they are throw away. The Vanguard is top line B/S OHV engine. They are thought more highly of, but by people that work on engines they arent considered a whole lot higher up the food chain than the Intek. In the low hp mower engine there is also apparently a "Briggs and Stratton" line of OHV engines even lower on food chain than the Intek. Apparently they are total junk and you'd be better off with a flat head if you can find one, they still make flatheads though EPA regulations are forcing them to be gradually phased out I think.

Looks like the small amount I paid for my 13hp Intek is about what its actually worth. Think I would rather gamble on a Chinese Honda clone than an Intek in future. At least the clone is a good top level design, just not Honda level quality castings and sheet metal, so may or may not last as well as a Japanese Honda.

I am hunting around for an older all metal flat head Kohler air cleaner assembly to use on my Intek. Kind of amazed they are going on ebay for $15 to $20 shipped. Probably just have to make my own air cleaner. Air filter elements for small engines are a real scam anymore. Air filter that should be $1.50 is selling over $10.

[Stephen in SOKY]

This one is the Vanguard. I found a kohler replacement at Northern for $1700. Said to be a direct replacement on Grasshopper mowers. In a last ditch effort I'm taking it to a small engine shop for an evaluaton/estimate. My backup mower has a B&S Intek 14.5motor. Can't get that one to start either. Grass is growing up around my ears. When they say if it weren't for bad luck I'd have none at all I can certainly relate!

[HermitJohn]

$1700 Ouch! Think I would be willing to do bunch adapting for that kind of money. You surely could find some decent used 16hp to 20hp engine that would do the job. Just looked on ebay. A brand spanking NEW Honda 18hp OHV GXV vertical shaft is $700 plus $105 shipping. Not to put down Kohler, but they have no advantage over a Honda if you can make the Honda fit. And personally I'd take a Honda over a Kohler. I dont even have any idea if a Grasshopper has vertical or horizontal shaft engine, but seems most modern garden equipment is going vertical. No matter think they had some horizontal Hondas similar price. You want GX or GXV commercial duty. Honda makes GC lighter duty engine.

On your backup mower, will it start with shot starting fluid, not stay running, but just start and die? Modern carbs not adjustable and EPA regulated with too small jets to run very lean unless everything is working perfectly. People dont drain fuel nor use fuel stabilizer after mowing season over so carbs get plugged up.

Oh just took a look for Kohler 18hp http://cgi.ebay.com/18HP-KOHLER-ENGI...3A1%7C294%3A50

It will probably bring more than current $200 bid but if it brought over $800 then I'd be totally amazed.