OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Chainsaws and Concrete Cutters McCulloch Chainsaws Briggs & Stratton 8HP Colt Major

My husband has a really, really old colt, rusty old blue thing, but it goes and goes. I saw an add for the 8 HP, raced out and bought it. Don't worry I got them to start it for me, listened to it, ( mere female thought it sounded good ), and paid for it, son put it in the ute and home we went. Husband goes out to look, smiles is happy it looks well cared for and no leaks from the trip. We get it on the ground, he can't start it. Hmmm, does what ever it is that you guys do and tells me "it's got no spark". Like come on guys, I'm trying to please the man, and they (the people who sold it to me) didn't do anything sly when they started it for me, they did tell me that I would have to buy a battery, but they used the pull start and away she went. What can I say to him ( who thinks he should be obeyed ), that won't make me feel like such a schmuck and that I bought a dud.
This is what is on the machine:
Model 191 707
Type 2155-01
Code 86091510
Electronic Ignition, Synchronised? Balanced? 3660 R/Min (SAE J607)

Update
Well bugger me, he has it going, and of course is trying it out on the back lawn. Smiles all way round. However, I know that the old blue thing will be next to fix, so stay tuned I will be back with questions and they will be best answered by someone who knows about old rovers, and I mean old, it's a ride on and it was his first, so he's kind of attached to it. When I can find out more about it I will post it and perhaps someone out there will be able to educate me!

Sounds to me like you bought a motor that is set up with a regulator to run and electrical charging system.

It will need a signal from the battery to say that things are powered up and its all good to make spark so it can start.


Your options are to find a wirirng diagram and fill in the missing bits and fit it up on the Colt with a battery and switch etc. In otherwords, finish the rest of the wiring system thats missing.

Or find a wiring diagram and remove the offending regualted battery stuff so that its just the basic 'i can make spark any time, earth me out to stop' system that a Colt or regular push mower runs.

Im not sure how you would do either but with some research im sure it will be sorted out fairly easily.



On another note. The motors ive seen on colts have a very short 7/8th shaft. What shaft does that motor that you bought have?? Its it a longer 1" i dod not think it will fit.
If it is the longer one that steps down from 1" to 7/8ths. You may need to space the engine up to be able to use it on the Colt.

Shaft length is measured from the face that bolts to the deck, not the housing. Easily accurately measured with two steel rulers that are square on the ends. One up from the flange on the engine, the other laying across the end of the shaft to make a right angle with the rulers.


You are no schmuck, you got them to start it for you, if you can not hear it go it does not go no matter what promises are made.
A bit of extra advice, I would suggest that you check the oil level and make sure its full before they start it for you. an engine with no oil wont blow smoke.

People think, its just a mower, they are all the same. They are not, they are all very different in their own little ways.

Hi Gabi,

You may find the Colt 8's Briggs and Stratton engine operator's manual and illustrated parts list useful.
Operator's manual:
http://bsintek.basco.com/BriggsDocumentDisplay/msozHP-K_ny7tH217FzoPu.pdf
Illustrated parts list:
http://bsintek.basco.com/BriggsDocumentDisplay/Z6nlxBVJ1DajI.pdf

It would help if you tell us what your husband did differently between when he thought he had no spark, and when the engine started. Then we would all be on the same page. It appears that either he had accidentally grounded the kill wire the first time he tried it, or it wasn't lack of spark. I could hazard a guess as to what was wrong: he wasn't sitting on the seat, so the kill wire was being grounded by the mower's seat safety switch. That is what happens in many of the cases of mysterious ignition failures on ride-on mowers that we get at Outdoorking. In your case I think the dealer will have bypassed the seat safety switch when he was showing you that it runs, then he will have (quite properly) reconnected the safety switch before you took the mower away.

By the way Gabi, welcome to Outdoorking. I hope we will be able to help you in the future, hopefully at least sometimes before you or your husband fixes it yourself.

Thank you Rodeobob and grumpy, husband tells me he doesn't know what he did to have it started, did the usual, cleaned spark plug, checked wiring and the safety switch side of things, he's just walking around scratching his head, as he walked away and when he went back and tried it again it worked. But thank you grumpy I will check out the engine operator's manual and illustrated parts, surely that will give me brownie points when i print them off for him to study.
The other rover that he has is an I/C 5HP Magnetron Industrial/Commercial Major Rover with cast iron bore and of course Briggs&Stratton. I would be so pleased to be able to tell him when it was manufactured, but most importantly if there are parts available. It presently needs reverse, so gear box issues, brakes, maybe a rebuild on the motor I think I heard him telling my son that the rings may need doing. Am I asking too much?
Thank you so much for the welcome grumpy.

Gabi, with regard to the 5 hp mower, if you post the same information as you did previously for the 8 hp mower (the long list of numbers stamped on the pressed metal cooling air cowl around the outside of the flywheel, just below the starter cord) I'll be able to tell you when the engine was made. If it is still the original engine, the mower will have been made about 6-12 months after the engine. FYI, the engine in your 8 hp mower was made on 15 September 1986.

It sounds as if the problem your husband had in starting the 8 hp mower was in the safety circuit that keeps the engine from starting unless the clutch is disengaged and there is someone sitting on the driver's seat. All the safety circuit does is ground the kill-wire (that is, the engine-stop wire that stops the engine when you turn it off). This happens to many people - they want to run the mower for diagnostic purposes, or they are hand-starting it rather than using the electric starter, and so no one is sitting on the seat when they try to start it. The pressure switch on the driver's seat grounds the kill wire whenever there is no one sitting there, because it's safer not to have the machine start without a driver. Most likely when he was checking things out after it wouldn't start, he has pulled the wire off the switch under the driver's seat. As soon as he did that, it would start normally.

Most parts will be available for the Briggs and Stratton engines in both mowers. There are universal technical overhaul manuals for all the Briggs and Stratton engines in the manuals section of this site (but you have to subscribe to that area to get access to them). Minor overhauls, including replacing the piston rings, are fairly routine operations, and are likely to be well worth doing if the 5 hp engine is using oil and/or blowing blue smoke in its exhaust.

Transmission parts for those old machines may not be available new. It seems to be usual for people to get second-hand parts from a similar machine that is being dismantled for parts. There will be several people here on Outdoorking who may be able to supply them, when you know exactly what you want. Alternatively you might put in an entire second-hand transmission. The old Colts seem to be very common, though they are not all the same: "Colt 5" could mean any of several fairly different machines. If you can post pictures of the Colt 5 mower, one of our members can probably identify it, and we can try to find out what transmission it has. That would be a step toward figuring out what is wrong with it.