OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Briggs & stratton 12hp i/c for victor pro 12 ride

I have just purchased a Briggs & Stratton 12hp i/c for victor pro 12 ride on. Had trouble with low power and found the choke had been wired shut. Have rectified this and tuned carby so the Governor works. Machine serial number TD4201107 under seat. Do you have any illustrations of Governor springs and choke application setup. TR

Hi Trevor, welcome to Outdoorking. Please post the full set of numbers (Model, Type and Code) that are stamped on your engine's cooling air cowl, plus a picture of your governor's external connections (remove your air filter and photograph the linkage that connects to your carburetor).

The owner manual for your mower is available in the manuals section of this site - subscription is required. Here are a couple of illustrations from it, relating to your mower.


As you can see, the Pro 12, unlike the Pro 16, has the choke connected to the speed control linkage, so the choke is automatically applied when you advance the speed control to the extreme position.


This is the carburetor for your mower. It is called a Large One-Piece Flo-Jet.


Here are the instructions for setting up the linkage for your speed control and coupled choke. Personally I find them indecipherable without photographs of your actual linkage, which presumably has been "improved" by the previous tenant. That is the area I want you to post photographs of.

Thank you for the prompt and detailed reply. When I return from work I will take pics of the linkage and search for the engine serial number. Where approximately are the numbers on the cowl? I will also subscribe and download the workshop manual. Looking at the last pic the choke lever and rod are missing. The small damper spring on the throttle rod is bent and the carb end is broken. I would think I will have to buy a new throttle plate to get the missing choke parts. Thank you again and I will repost in 2 weeks. Trevor

The long string of numbers is usually directly above the exhaust pipe where it comes out of the engine. You might find the small video on this site interesting:
http://www.briggsandstratton.com/model-number-help/
(Then select "Riding Mower Engines").

It sounds as if the previous owner has given your engine some rough treatment. Note that if it has run for a long time with the choke wired shut, there will be engine damage. The engine will have been running so rich that the oil will have been continuously washed off the cylinder wall by petrol, causing wear to the cylinder and piston rings, and some of the surplus petrol will have ended up in the oil sump, diluting the crankcase oil. You will need to change the oil right away.

I want to upload some photos but the upload button fifth from the left seems to be missing.. TR

When I started to type this, all of the buttons were missing. Now I have them all except the upload button. I see File Manager is working - you might try that. If it can't handle your pictures, you might try again in half an hour - if it isn't fixed by then, we may have to refer it to Bruce.

Trevor, thank you for reporting that the picture upload button was missing. What happened is that we had a major upgrade of the UBB Threads system that Outdoorking uses. The picture uploader has never been a part of the UBB Threads package, it is an application that Bruce had written specifically for Outdoorking. When the new system was introduced, the picture uploader slipped out of the process accidentally. Due to your report, Bruce is now attending to getting this fixed.

Engine details:
Model - 281707
Type - 0213-01
Code - 89062211

The pictures shows what remains of the throttle plate. The bright silver wire you see is connected to the choke so that it can be manually activated. The small spring on the throttle rod is broken on one end and I have no idea where it should be connected. On a brighter note someone has rewired the mower and used a relay and the accessory position of the key to turn the mower off using the key. Can you help me with the position of the small throttle spring and what will I need to activate the choke from the throttle lever?

Here is the illustrated parts list for your engine:
http://bsintek.basco.com/BriggsDocumentDisplay/Z6ntzHVJ1DajI.pdf

Here is the operator's manual:
http://bsintek.basco.com/BriggsDocumentDisplay/mssAIQ-K_ny7tH217FzoPu.pdf

Here is the illustration from the operator's manual showing the carburetor linkage:


As you can see, the free end of the anti-oscillation spring should attach to the hole right beside the attachment of the throttle link. Since it does not seem to be the right length for this, there is probably something wrong with the way the opposite end of the spring is anchored to the throttle butterfly itself. Perhaps you could post a picture of that end so we can try to work out what is wrong.

The silver choke wire appears to be the original wire link that should be coupled to the speed control system at what is now the free end of the wire. There are parts missing, however. Here is the illustration from the workshop manual:


Here is the governor linkage from your engine, rotated to the same view as the illustration:


Note that your speed control cable comes in from the bottom of the picture. This is the version shown faintly on the illustration, not the one shown as full lines.

As you can see, there are several parts missing from your engine (see red oval), and a wiring change has been made (the black wire with the red connector has been installed). At this point it would be very helpful if someone else with a 281707 or another engine with the rack and pinion governor control and coupled choke, could post pictures and explanations. Is the missing apparatus in the red oval a coupled kill switch? (The terminal at the bottom of the picture seems to be a kill wire terminal, with a wire running up to a contact that probably meets a pin on the pinion when the speed control is set to minimum. At present a wire has been run from the bottom terminal directly to the dashboard starter switch, so the mechanically coupled switch is not required.) If so, the main question is where and how the control wire for the coupled choke attaches to the back of the rack and pinion mechanism. Most likely it attaches to the rotating pinion which meshes with the vertical rack, behind the mounting plate.

Wow you are amazing.......... Yes the stop wiring was a bit of genius I thought but the down side is that all the safety switches have been disconnected. With this in mind I would like to get the choke connected to the throttle so that I am sitting on the mower when starting it. If anyone has any pictures of the behind the scenes connection for the choke rod it would be appreciated. The parts picture of the choke rod looks radical. If I get time when home next R&R I'll pull the throttle plate off and post some behind the scenes pics.

Yes Trevor, if you post pictures of the back of the governor rack and pinion assembly that would be useful. As you said, we hope someone else will be able to post a picture of the back of one in working order, and we'll see what is needed to get yours right.

I think we will need pictures of the other end of the choke link, where it attaches to the carburetor. The key question is whether there is a "lost motion" mechanism there, or we have to make the link move exactly the right distance to get the choke fully closed and fully open. I would hope to find a spring-loaded stop at one end of the link. Incidentally, this is what P/N 261610, Link - Choke, is supposed to look like, before "tenant's improvements" are taken into account:



As you know, reconnecting all the safety switches is essential before the mower will be back in working order. If you can't have a coupled choke you will at least need a dashboard choke control, but putting things back the way they came from the factory is the best solution, because it has been tested and developed to get the bugs out of it. (Also, you can probably get parts for it if it is to the original design.)

The choke butterfly is spring loaded open which is toward the throttle plate. Without looking I would think that there would be a lever behind the throttle plate that pushes on the 216 link to close the choke and the spring action opens the choke plate. All that remains of the safety system is the 4 wire plug loom under the fuel tank back to the park brake switch. The seat switch and all under dash wiring including diodes has gone. If all else fails I will fit manual choke cable.

I think the governor control's rack and pinion system consists of a rack moved by the speed control cable, and a sector of a gear meshing with it (probably only a 45 degree sector, of fairly large radius, so the sector only rotates about 30 degrees for the full movement of the speed control cable). The sector will have a long arm projecting from it, and the 216 link will attach to a hole in the end of that arm. Your arm-and-sector part is probably still there, and it may only be necessary to re-attach the (repaired or replaced) 216 link to it. This should be a lot easier than setting up a manual choke. However a manual choke version of your engine does exist, and the relevant parts are shown in the illustrated parts list.

Here is the wiring diagram for your ride-on:


In my view, restoring the wiring to original is essential to make this mower work properly and safely.

Got the wiring sorted so a future project could be to get all safety gear working. Next is to order the 216 rod and work on choke. All the belts need adjustment and main belt is twisted so will be replaced. The wiring diagram was a big help when repairing wiring. It's good to have such a useful site.

Trevor, this thread will be much more useful in the archives if you complete it by posting a picture of the back of your rack and pinion governor control plate, then when you receive and fit your new 216 rod, posting pictures of the assembled choke and governor system. I will leave this thread open for now so you can do this.

For the record also, I am pretty sure victa deleted the little kill switch for the throttle at the factory, I have had 3 of these through the workshop and none of them have it, the choke linkage though should almost certainly be there, but some mtd's ran a second cable for the choke.

Ok home on 1st of Jan so will get picks of rear of throttle plate and post them. There is a local mower shop so hopefully be able to order B&S parts with no trouble.