Briggs 5 hp Governor Slow Reacting

[pvanv1]

I have a Briggs 130252. This motor has the pulsa-jet carb with rotary lever choke. It has gear reduction. Unfortunately, the type and code numbers have been damaged beyond readability. The motor is from the late 1970's. I use it ion my home-built log splitter. The gear reduction was needed in order to get a reasonable speed to the hydraulic ram.

At issue is running with the governor. The throttle does not react quickly enough, and the motor will stall if I set a decent engine speed and attempt to split anything heavy. If I connect the throttle cable directly to the carb butterfly, I can open the throttle, and have adeqate power, but then I need 3 or 4 hands to operate the splitter (one or two for the log, one to operate the spool valve, and yet another to modulate the throttle).

Of course, if I run WOT, the motor screams when it's not under load -- probably running over 5000 rpm, which is way too hard on that stock motor. If I do that too much, one day I will probably throw the rod.

The governor is operating, and it will compensate for small changes in load, but it does not throttle-up fast enough for a bigger load.

If it matters, I am in Western New York (near Buffalo, so we occasionally get below 0F in winter, and have never hit 100F at the airport weather station on the hottest summers.

Any ideas?

[bobodu]

I think your pump is too big...If you had to slow it down to keep the ram from flying...you are putting out more flow than pressure. That small engine just can't move that much fluid PER REVOLUTION when the pressure builds.
But the overspeed is a sign. Do a google search for adjusting governor or just look down a few threads.

[KE4AVB]

Single Cylinder L-Head Service Manual for your reference.
http://dl.dropbox.com/u/12502267/B%26S%20Service%20Manuals/01_270962SingleCylinderLHead.pdf

[pvanv1]

Yes, the Briggs gear reduction is to compensate for a large pump. But IIRC, I am accomplishing the same thing as a smaller pump by turning the bigger pump slower (X cc of oil per revolution), and keeping the engine at a decent RPM. Without reduction, I would want to either slow down the Briggs, (which would take it out of its peak torque curve), or run a smaller pump. Going with a smaller pump and no reduction would produce the same cc flow per revolution as I have now, and I would have the same symptom. Yes, it would be OK to have a bigger motor -- that would definitely work (someone probably has a u-tube video of one of these powered by a Chevy 350) ... but based on the fact that I can throttle up manually and have enough power tells me that I have enough hp now -- I just need to deploy it quickly -- which I can do manually. I hope I can fix the governor to react as quickly as I can slide the throttle cable... seems reasonable.

The governor is adjusted according to the B+S manual, and does operate... it's just sluggish. The governor on my Briggs "16.5 Torque Power 21M314- 0019 (21M314-3019)" on my snow blower reacts "instantly" when I engage the auger, even under full load. That's the reaction I would like from the old 5 hp unit... I'd like to go to WOT in under a second... seems reasonable.

Thanks for the link to the B+S manual... I actually already have it... but it 's reassuring when a forum member is so forthcoming with info!

[bgsengine]

The governor is adjusted according to the B+S manual, and does operate... it's just sluggish.

That's called Governor Droop - On an otherwise properly operating engine assuming carb, fuel, compression, etc all are OK , governor droop is adjusted by changing the hole the governor spring sits in , in relation to the center line of governor shaft and governor control lever.. If there's no additional holes in either to hook governor spring into, you may also need to replace governor spring (they do weaken over time) or change to a heavier spring,. This is all assuming that you have an ACCURATE TACHOMETER with which you should first VERIFY your engine's top no load RPM is within specification (Usually, for general purpose engines, it is around 3600 RPM) - If it is not within top no load spec, you'll need to adjust that first before going forward with any other troubleshooting.

[bobodu]

Going with a smaller pump and no reduction would produce the same cc flow per revolution as I have now

No !!! You would have less flow per REVOLUTION !!! You might have the same GPM.Slowing the pump down WILL NOT compensate for a small engine trying to push a lot of oil under pressure !!! It will STALL the engine !!! You are trying to push "X' amount of oil for every rotation no matter what SPEED.
Take a jack. You can pump it easily EMPTY with a 1 foot long handle. Put a LOAD on it and you will need a three foot handle.....don't matter how fast you pump.
That is why they make two stage pumps.....first stage is flow to move the ram quickly into place. Then part of the pump shuts off and the high PRESSURE side takes over. I have seen house moving jacking systems run with 5 hp engines.

[RoyM]

The engine is close to 40 years old, the governor will not compensate for wear. What the others said, if you have to run the pump that slow to control speed, it is too big. What is the ram diameter?

[pvanv1]

Going with a smaller pump and no reduction would produce the same cc flow per revolution as I have now

No !!! You would have less flow per REVOLUTION !!! You might have the same GPM.Slowing the pump down WILL NOT compensate for a small engine trying to push a lot of oil under pressure !!! It will STALL the engine !!! You are trying to push "X' amount of oil for every rotation no matter what SPEED.
Take a jack. You can pump it easily EMPTY with a 1 foot long handle. Put a LOAD on it and you will need a three foot handle.....don't matter how fast you pump.
That is why they make two stage pumps.....first stage is flow to move the ram quickly into place. Then part of the pump shuts off and the high PRESSURE side takes over. I have seen house moving jacking systems run with 5 hp engines.

No, Your analogy is in error. Think of your bottle jack equipped with either a 1-foot handle or a 3-foot handle. Easier pumping with the 3-footer, but if the end of both handles operates at the same incher per second, the long handle will operate slower.

2-stage splitter pumps are for convenience only. You still need the "geared down" or "smaller pump" effect to get X pressure from Y HP (or, technically, ft.-lbs.) I understand your idea, but fundamentally, I have the correct setup, and it did work OK years ago... but the governor droop is likely what I am seeing. Will know more once I get some better weather. Yes, the motor is old, but has been very well maintained, low hours, superb compression, great ignition, and runs like new.

[StarTech]

Talking about it screaming at full throttle is the first issue I would tackle. Get yourself a good tachometer and find exactly what the rpms are doing. Sometimes you just can't reply on the sound. Two different running at the speed can sound like one is running slower than the other. The engine should be running between 3600 and 4000 rpm top no load speed. You might have a bad governor gear as they are only made nylon plastic with metal weights. Even with little usage it the age that can be factor especially with any plastic parts.

It could also be simply that fuel mixture is out adjustment (too lean probably) and just can't respond until get rich enough.

[bobodu]

I give up. I have built splitters, powered jacks, dump trucks...front end loaders, put hydraulics on antique tractors and even wheelhorses....you are pumping too much oil per revolution and that the cold hard fact.
The longer jack handle gives you MORE LEVERAGE ...speed doesn't matter !!! You are pumping Xcc of oil per pump...no more and no less. If you bothered to look up pump specs you would see a column called "Displacement".
Did you bother to google Governor adjustment?? Well now that you said it worked before....
https://www.google.com/#q=briggs+governor+adjustment