OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Briggs & Stratton 4 Stroke Utility Mower

Hi Guys,
I picked up something a little different during the week. An old school Briggs and Stratton 4 Stroke on a Victa Utility Base. I get plenty of 2 strokes come through for repairs or at the local junkyards on utility bases but never 4 strokes so I thought why not try out something different.
I thought the mower was in excellent condition and was a little perplexed why it was thrown out in the first place as it had obviously been looked after given its age and overall condition.
In short I bought it home and took the air filter off after establishing it was fully blocked with dirt, added some fresh fuel and it went 3rd pull and ran perfectly. Nice idle and nice full speed.
I�ll be honest here, I haven�t done these type of carby�s before as I don�t see many in a good enough condition to repair and sell on however this one I thought was a little unique and still had plenty of usable life.
I was thinking of converting it to a pulsa prime carb but I wanted to keep it original as the engine already starts easy.
As a result I have a few questions for consideration.
1) I always replace the pulsa prime diaphragms and rarely if ever have problems with them so I am assuming when you go to clean up this style of carb you should follow the same principle?
2) If replacing the diaphragm can someone confirm the type?
3) The knob on top was missing so I am assuming you could replace it with a similar stove/bbq knob? Has anyone found something suitable? I just adjusted the knob with plyers during testing.
4) Any other useful tips would also be appreciated.
Everything else looks pretty standard.
I�ll clean it up by
Servicing the starter clutch;
Air Filter;
New Blades;
Regap the magneto;
New plug; and
Replace the oil.
I have included some photos of something I hope is of interest. Sorry I don't have the model type and code available at present.



Thanks
Jaffa

That is interesting, only 3HP! What is that missing knob for? I have never seen one of those on a Briggs before. Those air filters always block up since they suck from underneath where all the grass and dust is flying around. If you weren't going to keep it original replace it with a snorkel air filter.

I may be wrong but that looks exactly like a 'D' shaft or grub/set screw. Very common on hifi, instruments and electrical/electronics equipment. You get a knob with a round socket and little grub screw to hold it.

That and the split shaft spline are the most common for rotary switches and potentiometers, those are push on with a matching spline.

If anything the difficulty more would be getting something that looked appropriate for the mower. Depending how close to original you want it, if you can find anyone that knows or has pics.

Just google set/grub screw konb or d shaft knob, plenty of affordable ones floating around, Jaycar, Altronics, RS or similar local electronics shop should have something off the shelf that will work, as I said some may look a bit weird on the mower though, might want a more 'industrial' looking one of a bigger size.

Or service the air filter frequently - which owners almost never have done.

That knob throttle control also appeared on some Masport 1970's models. It was a flanged knob, with a diamond shaped top section to form the pointer. If the shaft diameter is 1/4"/6.35mm, a set screw retained audio knob will fit - you may have to mark your own pointer on the flange though.

No doubt it would also be available as a Briggs genuine part; if the Model/Type/Code info can be supplied, we can find the part number.

That's in the Mayfair gold hammered finish paint I am having great difficulty finding for my restoration.
The motor looks to be a later series than what originally was on there.

Hi Jaffa, nothing abnormal about the knob setup, although i've never seen one on a utility.
As for the carby, a search on ebay will get you what you're looking for, just note the shape of the mounting area of the carb to the tank.
I'm not convinced that the motor is a factory fit on that base, I'm not even convinced that base is meant to have a petrol powered motor on it, the raised bit around the front almost looks like an electric motor powered utility base, although i could be wrong. Could you take come pics of the base where the engine mounts and possibly a pic of the underside to determine if it's got a victa blade setup on it.
Good to hear from you,
Cheers, Ted

Have a look at this thread Pete, i'd be interested to see if yours is the same as this as it would answer a few questions. " Did Victa use the "failed" electric base and fit 4 strokes on them at a time when the full crank was the only available 2 stroke? "
4 stroke utility

might be on some other machines but i have only ever seen them on old masports so far . whirlwinds ! . and there are at least two different diaphragms for those . but if its starts and runs well . same old story , is it ain't broke dont fix it , they can be a pita to get the choke correct . maybe it was a powertorque base , same bolt pattern . one extra hole on one side is there ?

Doubt it was ever a power torque base with those style non bearing wheels and that hammertone paint.

Kinda hard to tell from the angle but there doesn't appear to be a hole for the exhaust on the base. My (completely untrained) eye says it must have been 4 stroke (unlikely) or electric from birth ...


Still, What are we as Australians if not adaptable!

If it works well use it.

Pete

Guys thanks for the input.
I�ll start with the Model, Type and code so we can clarify the exact type of diaphram please Gadge/ Theo.
Model 92502 Type 1056-01 Code 80050125
I have watched a couple of Donyboy�s video�s on youtube and I don�t think the carb will cause to many issues once it is fully cleaned up. It should be reliable once the diaphragm has been replaced.
I have inspected the mounting arrangements and provided some additional photos for clarification. I haven�t had a chance to pressure wash the mower yet so excuse the mess.
The engine has the spacers similar to the thread mentioned by Theo so this might give something away for those more experienced.
The mower appears to have a Victa blade plate from what I can see. It is fitted with standard victa utility blades.
I have also managed to source an original knob to replace the missing one. I�ll pick it up from the old mans place at xmas.
I�ll await your thoughts.

its not correct colour , and if you look close . you will see a hole in the base too .... but cheers , i would never have guessed !!! wheels tend to get changed with age , not too many worry if they have bearing or not .
but cheers for letting me know

Righto, the IPL is at http://bsintek.basco.com/MDEXResultsPages/PDFDisplayPage.aspx?fileName=Z6kotCVJ1DajI

The throttle knob P/No 299858 is available, but rather exy - over $20. Just as well you've found a secondhand one.

The carby diaphragm you need is P/No 299637. Less than $10 for an aftermarket kit; HERE, for example.

I don't think the engine is original to that chassis [earliest record of a Briggs engined Ute I can find is MY 1988-9], but I'd say the deck colour is original - Victa offered a Mayfair Ute from 1980-83.

Finally received the new diaphragm and it was quite easy to install after watching a couple of you tube videos.

I have given the carby a good once over and included a few photos for reference. As expected the internals were in quite good condition for their age.

Everything cleaned up nicely.

I originally set the mixture screw 1.5 turns out and the mower would not start upon being serviced. I wound the screw out an extra turn and it fired up and ran a little rough. I managed to get the engine warm whilst adjusting the mixture for smooth operation. I found the mixture screw on this carby to be very sensitive. Despite these difficulties the mower is running quite well for its age.

Just a few queries/ thoughts on this type of engine as their appears to be a few differing opinions online.

1) Best method of adjusting the mixture screws during a first start up. If I need to re-adjust I will.
2) When you turn the engine off and its warm � it�s a bugger to start because the choke closes�� any tricks to avoid this?

Bump up..... Gave it another run last night and made a slight adjustment to the mixture screw. Still after some advice to make sure I have it spot on.

Cheers

Hello Pete, with those older style choke carby's, sometimes you just cant get them right. you've done everything you can correctly by the sound of it and just need to adjust at full RPM and then a very minor adjustment(generally 1/8 of a turn either way) at idle for fine tuning.

Got back from the old mans after some time away and he got me the last part I needed to finish the mower. It started today on the third pull and ran perfectly after three odd weeks of not starting. Some photos of the finished product ready for a new home.



All up I am happy with the result for a very low cost. Another one ready for a new home !

Also meant to say thanks for Theo and Gadge for there help with this one.

Some of those type of carbys have a "clock" spring on one end of the choke butterfly shaft and some don't. The clock spring ones seem to be too strong for the vacuum to pull the choke open when the engine is getting a bit older. You can take the spring out and it doesn't seem to make any difference to normal operation and makes them easier to start when warm so it may be worth looking to see if your machine has the spring.

Thanks Trev, I am pretty sure this one doesn't have the spring. I refined my hot start procedure and it generally starts back up after a couple of pulls now. Being a utility type mower this shouldn't cause too many issues (i.e. no catcher to empty)