OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines briggs and stratton help

yeah the black wire wasnt clamped on properly after the last time i took it off and when the mower was reving the wire was shaking around and hitting the metal giving it no spark.

it only blew black smoke after the first time i started it for the first 5-10 seconds, now its fine with no more black smoke and when its cold starts in 2-3 strong pulls (wih 3 primes) then when its warmed up just takes a soft first pull(no priming).

grumpy u are right between the turtle and the rabbit on the throttle it revs like crazy but if i put it on full(rabbit) it revs normal and if i put it near the turtle it idles away. but in between it revs liek its going to blow up lol,

Engine speed should increase smoothly from 1750 rpm at idle, to its maximum which is probably 3000 rpm flat out. If it rises above maximum anywhere in between, the governor isn't working properly. It's a very simple mechanism - just an air vane beside the flywheel fan, and two springs on a tin plate. I suggest you look at it carefully, and if possible post a photograph of the tin plate and springs. Bruce is the expert - he can normally tell people what is wrong very easily.

is that at the back of the engine? what controls the engine reving? what moves as it revs up and down etc?

are u talking about this(pictures below) or the other thing behind thE fuel tank?

This is when the switch is turned to turtle:


This is when the switch is turned to Rabbit:


sorry bad phone camera
This is when the switch is turned to the middle of the 2:

The speed control lever moves one end of one of the governor springs, stretching it slightly as the speed setting increases. The other end of the spring is indirectly connected to the throttle butterfly on the carburetor. The air vane near the flywheel fan is also connected to the throttle butterfly. Essentially, the spring tries to open the throttle and the air vane tries to close it. When the speed control is set to minimum, the air vane and spring are in equilibrium at 1750 rpm. When the speed control is set to maximum, the spring is more stretched so the air vane has to push harder, and equilibrium is reached at 3000 rpm. The spring should be stretched smoothly and evenly as the speed control moves from minimum to maximum. I'll leave it to Bruce to comment on whether that is happening in your pictures - I can't see what is happening, except that the bottom of the spring is moving from right to left as you increase the speed setting, and the upper spring looks like it might not be connected.

so could the spring be streched or not on properly? it looks like it on properly

There are usually two springs pulling in opposing directions, but only one is visible in your picture. However right at the top edge of the picture I seem to see the bottom hook of the other spring, not connected to anything. Perhaps it should be connected to the center hole of the pivot-plate at the top of the picture? Dunno, I've never actually seen a Quantum XL50, and your picture only seems to show the bottom half of the governor.

You should be able to move the air vane with one finger and see the governor operate. You should also be able to see the change in operating pressure for the vane, as you advance the speed control.

If it is a two-spring governor and one spring is disconnected, the engine is likely to over-rev in a big way.

Grumpy on a quantum motor there is not air vane, it is a internal govenor that operates from the bottom of the crankcase.

If it is a two spring govenor and one is disconnected it will rev less as there is less spring tension to open up the throttle.

As for the other problem with the revs between idle and run I am not sure.

Thanks Joe, I looked at the B&S parts list and there only seems to be one spring, too, so it just isn't anything like the system I'm slightly used to. I'll leave this one to you and Bruce, as I should have done in the first place.

i found the problem the metal bracket what holds the spring at the other end had bent probably from going under a tree.

If I recall correctly Bruce has identified that as the most common governor problem on modern B&S engines. It probably became more common when they seemed to switch to making the governor bases out of cheese instead of steel.

yeah lol they really are i bent it back with my fingers.

lol dont know if i should of done this but today i put Lucas Upper cylinder lubricant with injecotr cleaner and fuel coniditioners in the fuel of the mower today lol cause i was doin it to my car why not the mower lol!

the botttle says: Lucas Fuel Treatment is formulated for both gasoline and diesel engines, carbureted or fuel injected. It gives your fuel system what it really needs - a blend of super slick oils and additives with a high detergent action that allows the engine to operate at maximum efficiency. Also, it cleans and lubricates the carburetor and injectors and causes the fuel to burn more thoroughly for increased power and less fuel consumption. Lucas Fuel Treatment should definitely be used in vehicles that require leaded fuel because it actually replaces the benefits of lead in gasoline without causing harmful emissions. Use it to pass smog tests. Finally, it totally neutralizes the harmful effects of low sulfur diesel fuel.

Key Benefits

* A great tune-up in a bottle
* Cleans and lubricates the fuel system
* Neutralizes low sulfur fuel problems
* Increases power and miles per gallon by burning excess exhaust emissions
* Increases the life of pumps and injectors

I recall that quite a few years ago when I last read a Holden Owners' Manual it said that the use by owners of any kind of fuel additives is unnecessary, and is discouraged because it 'just adds to running costs'. I also recall that in the early days of port fuel injection the oil companies were a bit slow to put injector cleaner in the fuel as a standard component; instead they were peddling bottles of the cleaner as an additive to be used by car owners. At least one car manufacturer objected because their tests showed that the injector cleaner was prone to stripping the tern plate off the inside of the cars' filler necks. Of course the oil companies then began putting the cleaner in all of their fuels as one of their standard additives.

Far be it from me to say anything nasty about somebody's commercial product sold in good faith, but I personally won't be putting that product in the tanks of my B&S engines.