OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Briggs 191702 on Cox Ride-on

Hope this link works







Fortunately I managed to break the spring on the pull start on this before it hospitalised me. I bought an aftermarket starter for $80 and bolted it on, eventually lined it up correctly and cranked it. Sheared off the keyway on the flywheel (aluminium, perhaps a bodge but I'm not familiar enough with these engines to know. I made a steel key and its holding so far. It won't start and I don't know what type of carb this is and whether I have the choke engaged or not. It sounds like it wants to go but snuffs it after about a second. Any advice appreciated.

I also managed to cook my starter relay, 30 amps ain't enough. it's fused on and it cranks whenever the battery is hooked up. If anybody has an idea what model of mower this started out as, I'd like to hear your thoughts.

You definately need the aluminum key as it stops the crankshaft from bending should the engine suddenly stop. I would also reccomend running the engine with the top cover on as it will overheat without it.

Thats not the original carby there, it looks like one originally off a horizontal shaft motor with a home made manifold, but if it works its good

The original Briggs flywheel key is actually zinc according to the manual. Do not use a steel key, that just loses the safety feature that prevents the crankshaft breaking if the mower hits something it can't handle and stops suddenly.

That inlet manifold is home-made as Joe said. I can't see the carburetor well enough to know what kind it is, or even if both pieces are from the same carburetor.

Car starters draw around 150 amps. That little one would draw less, but more than 30. The outcome was what could have been expected. I think this job will go better if you work one bodge at a time, if it really has to be bodged at all, rather than trying to make someone else's mess into a mower without fixing the messups.

Thanks for the replies fellas. There are no markings on the carb at all except for "choke". I suspect it is off an ancient motorcycle or similar. Following your advice, I will make an aliminium key and install it. Unfortunately the starter gear on the MIC starter motor has sheared itself flat and I won't be tinkering with this again until I source a replacement. It was listed as a replacement for B&S STR5983, but the pitch seemed wrong from the start. Perhaps you know the specs for the correct gear?
http://brisbane.gumtree.com.au/c-Ca...tratton-Ride-On-Mower-W0QQAdIdZ272864308

I have a Mexican Walbro carb off the other engine that I might try to fit to get it running. This one is some kind of mystery.

Do you have the missing cooling air cowl for that engine? If so it will have a long series of numbers stamped on it that may help us to identify what carburetor and intake pipe it should have. You have a better chance of getting a good result if you put it back to standard condition.

Cox Engine

191702 0666-01 76020211
8hp
1976 Feb 02

The plan is to get this thing into as close to it's proper condition as I can. I'm going to contact Cox mowers to see if I can get a bonnet for it. I've no clue what to do about the rear wheels yet, they seem to be off a Morris minor. On the positive side, the cutting gear looks to be largely untouched.

That engine is one of the few to be equipped with the Magna-Matic ignition system, somewhat famous for two features. First it was described as "awesome in its complexity". Second, it was the only Briggs ignition system (AFAIK) to have not only centrifugal advance rather than fixed ignition timing, but it also had adjustable ignition timing: the breaker cam on the camshaft can be unlocked, rotated, and re-locked in a different position.

In the various illustrations of that engine in the manual (search "190000", and follow the 191000 stream where necessary) it is shown with a large 2-piece flo-jet carburetor.


Note that at present it appears that your engine has no governor connection between the mechanism in the crankcase, and the oddball, home-made carburetion setup. This is a recipe for blowing up the engine.

The correct intake pipe is a simple right-angle fitting, used on many B&S engines with the large 2-piece flo-jet, but you will not be able to fit it until you dispose of that ludicrous exhaust pipe-muffler arrangement, about which the less said, the better.

If you want to learn even more about B&S engines, including that one, than you will ever want to know, you can access the overhaul manual here:
http://www.tpub.com/content/recoveryvehicles/TM-5-4240-501-14P/css/TM-5-4240-501-14P_70.htm
Use the "next" button or increase the final number in the URL from 70 to go directly to other pages. There are 224 pages in the manual.

Thanks mate, yer a legend. I guess I'll start looking for flo-jets. The carb on it looks like the front half of whats in your illustration. Maybe the guy cut it in half or something?

It does look rather like a cut off two piece flo-jet, as you say. He may have cut it off at the choke, because the part to the right of the choke is just a mounting for the air cleaner. Remember there are several kinds of flo-jets: that one is a large 2 piece. The large one-piece is rather more common. It looks like this:



The one-piece is easier to fit to vertical-crankshaft engines because it bends to the right, which gets it out of the way of the exhaust port. The 2-piece bends downward, which is fine for horizonal crankshaft engines but on verticals it requires an exhaust pipe design that gets out of its way. That is why I think you need to get proper original parts for both intake pipe/carburetor and exhaust pipe. If you use the wrong carburetor you have to expect problems getting the governor linkage to work.

That engine is unusual, in my experience anyway, because of the centrifugal ignition advance system. I think it would be a sufficiently rare bird in Australia to be worth preserving as an interesting model.

Thanks again, you are a fountain of info. I'm glad I found this site as I'd have got nowhere fast without it.
Following a bit of an appraisal of the situation, my draft plan is to follow your advice and get the thing back to standard. The exception to this is the electric start, my poor old bones won't stand up to pull starting these things any more. It has a steel ring gear on the flywheel and bolt holes for the starter unit. The flywheel gear is the wrong pitch for the 16 tooth starter gear, so I'm going to attempt to replace it with the alloy one listed in the storefront (when the accountant permits it) In the meantime I'll get to cleaning up the cutting deck, checking bearings etc and sussing out this Cox friction drive thing. I'll put up some pics as I go along, as to do this properly looks like it'll take a lot longer than I thought.

Hi Adrian, I think it's great to see you have decided to restore it back to standard. I hope it all goes well for you and we are looking forward to seeing the pics, as you go along.

Thanks Deejay, I'll try not to stuff it up too badly.

found this site with some good info on the flojets.

http://outdoorpowerinfo.com/repairs/briggs_medium_two_piece.asp

This appears to be the carb which is currently on the monster.



Whether it's supposed to be or not or was an option is yet another mystery.

Note
also found this carb identification site

http://www.asecc.com/data/briggs/carbtyp.html

this is supposely the large flo-jet 2 piece

I agree your current carburetor is a medium 2-piece flo-jet



There are very few illustrations of vertical crankshaft 190000 engines in the manual, they are mainly horizontal, and have the large 2 piece flo-jet:



However there are some illustrations of the horizontal crankshaft, cast iron 190000 with the medium 2 piece flo-jet



(That isn't very relevant since your engine is aluminium).

Finally here is a rather enigmatic drawing of a 191700 like yours that seems to have a large one piece flo-jet:



I suggest you have a look at this in context, in the overhaul manual here:

http://www.tpub.com/content/recoveryvehicles/TM-5-4240-501-14P/css/TM-5-4240-501-14P_139.htm

The previous few pages, and that one, are the sources of the preceding illustrations. If you can break the code on the B&S way of expression, you can probably find the actual answer. Meanwhile it seems your engine has a B&S carburetor, but whether it is the right one is unclear. It certainly has the wrong inlet pipe and exhaust pipe.

Incidentally, and completely off-topic, your engine also has the reciprocating synchro-balance mechanism to make it run with less mechanical vibration. It seems to have every complicated mechanism B&S made at the time: kind of a top of the line model for keen mechanics to practise their skills on.

Thanks Grumpy, that exhaust is my fault. The existing one was a broken off stub and I put that in just to have something to stop it blowing flames and wrecking my hearing. I'll put the correct one on as time permits.

As to the carb, I'll check out that manual and do some more googling to see what I can dig up. I actually hope that it is supposed to be there and it's just going to be a matter of getting the missing bits off it rather than trying to source a new unit. I'll start looking for an inlet manifold as well. I'm a bit puzzled as to why the guy would have changed it.

I can make a wild guess that it originally had a large one-piece flo-jet that bolted directly to the cylinder, and he had a problem with it (usually it is flooding with the large one-piece, and you have to replace the float chamber seat, which is only easy if you read the manual first), couldn't fix it, found a junked engine with a medium two-piece, and decided it was a sign from heaven that he should make up an intake pipe to let him use what had come to hand. I'm a great user of junk-box parts to fix things myself, but I don't redesign engines to use up my junk, because I've learned the hard way that it ends up causing lots of work and lousy results.

Large one-piece flo-jets would be the most common carburetor ever fitted to ride-on mowers, and they are on many other older Briggs engines in the larger-capacity categories. If you decide that is what it had originally, I think you can get one very easily. I'm not quite so sure about an air cleaner for it, but if you get the carburetor from a dead ride-on, the air cleaner will probably still be attached. Again, if that is what was used originally, setting up the governor may just be a matter of taking the linkage parts off a dead engine.

adrian, I finally weakened and consulted B&S. Here is the illustrated parts list for your engine:
http://bsintek.basco.com/BriggsDocumentDisplay/default.aspx?filename=Z6kswDVJ1DajI
Here is the Owner Manual:
http://bsintek.basco.com/BriggsDocumentDisplay/default.aspx?filename=msozHP-K_ny7tH217FzoPu

As you can see, it had a large one-piece flo-jet, bolted directly to the cylinder with a standard flo-jet gasket, without any kind of intake pipe. The sketches and part numbers for the governor parts are there too, and you can see the air cleaner.

Also, even the gravity feed model had an in-hose fuel filter, so I just lost an argument with aldot in another thread. It even looks like the one igor54 said it would be.