1991 Lawnflite - 5hp Briggs & Stratton - Engine won't run

Dear All,

I'm new to the site so please forgive me if I'm posting wrong and let me know what I should do in future please!

My husband and I have started a small lawn care business here in Wales, UK. We picked up a 1991 Lawnflite self-propelled lawnmower with a 5hp Briggs & Stratton engine as a secondary to our main mowers. We have a second Lawnflite which runs the same engine and unfortunately it broke (hit a washing machine pole pretty bad...) so we are hoping to swap the engines over if we can get this one to start, which it wants to but won't quite get there. I'm hoping someone will know some tips and tricks or which part to change out :smile:

We have tried Easy Start, sprayed Carb Cleaner through the air filter pipe and on the carb pot (sorry, not sure on technical terms - it's a small pot that came off the bottom of the carb). There's new fuel in it and plenty of oil. When trying to start the cord pulls well, turns over with plenty of compression, and starts to spark (we know the plug works). However it splutters out - it gets almost there and then dies. If it were a car, all it would take is a bit of a rev when trying to start! We aren't sure what to try next. We have a local place we could take it but if it's something simple that we can do ourselves we would kick ourselves if it costs a lot for them to check and fix. Can anyone suggest anything? I can post a video (I think) of my husband trying to start it if anyone needs it.

Side notes:
= It does have an electric start, but there is no key - whilst the keys are pretty cheap and universal, I don't think the batteries for the electric start are, so we don't intend to use it at all in the future.
= It has different speeds, but it seems whilst my husband was trying it yesterday my father helped and pulled at the speed/throttle lever a bit and now it's somewhat loose - but this hasn't made any difference.

Any help will be much appreciated!

- Rebecca

- Could you post a picture of both mowers so we can verify that the engines are the same?

- If the engines are the same, you should be able to swap over the fuel system (carburetor, fuel line and fuel tank) from the totaled engine to the new one. That should get the new one up and running.

- The correct name for the "carb pot" is "float bowl". Inside is the float and float needle.

- Does the speed lever still work? Again, a picture would help here as well, or a video of the speed lever being operated.

primerbulb120 said:

- Could you post a picture of both mowers so we can verify that the engines are the same?

- If the engines are the same, you should be able to swap over the fuel system (carburetor, fuel line and fuel tank) from the totaled engine to the new one. That should get the new one up and running.

- The correct name for the "carb pot" is "float bowl". Inside is the float and float needle.

- Does the speed lever still work? Again, a picture would help here as well, or a video of the speed lever being operated.

Click to expand...

- Pictures:
This is the non-runner (nicknamed 2nd Red)

And this is the one that hit the pole (nicknamed Big Red, who we want to put the other engine on)


- Sounds simple, I'm sure we can do that - is there a guide or video you would recommend following?

- Thank you :wink:

- I think so, it works on the first couple of speeds and then seems loose. Here is my husband working it:

Thanks!

Rebecca

bmgreenwood said:

- Pictures:
This is the non-runner (nicknamed 2nd Red)
View attachment 37793View attachment 37792
And this is the one that hit the pole (nicknamed Big Red, who we want to put the other engine on)
View attachment 37794

- Sounds simple, I'm sure we can do that - is there a guide or video you would recommend following?

- Thank you :wink:

- I think so, it works on the first couple of speeds and then seems loose. Here is my husband working it:

Thanks!



Rebecca

Click to expand...

Thank you for the pictures. The engines are most definitely the same, so you will be able to swap over the fuel system with no problem. You might swap over the throttle control from the old mower as well to rule out any possiblilty of a broken throttle control.

To swap out the fuel system:

- There are four bolts holding the fuel tank on. Three are around the starter, one is under the tank at the back of the engine (carburetor side.) Remove all four bolts.
- Remove the air filter and carburetor assembly, disconnect the throttle linkage and the fuel line if necessary.
- Put all the parts on the new engine.

That's pretty much it. See if the new engine will run.


How long has it been since you hit the washing machine pole?

Thanks for getting back so quickly!

We will give it a go this weekend and see what happens. I was thinking about maybe changing the cable for the throttle, or at least having a look at how it all works and how it may be damaged, and quite honestly it didn't click about changing it over... my tired brain!

It was hit about 2-3 weeks ago. We've looked into fixing it, but it had been modified by the previous owner before we bought it - there are supposed to be 'shear bolts' on the blades and a plate to hold it all together, meant to break the blade off if you hit something instead of damaging the engine; it looks like the previous owner drilled out the shear bolt holes and bolted the blade onto the boss assembly so it wouldn't come off (maybe they hit something in the past and didn't want to replace it...) but I'm sure you know what it meant when the pole was hit. We have looked into changing the boss assembly but it's just going to be easier to switch things around between the two engines and get the second one going instead.

There is a difference between the two mowers, one having a roller and plastic deck and the second having just a metal deck. My husband prefers the roller mower so if we can get the second engine running we will probably then switch the entire engine and blade assembly onto the roller mower, which means we wouldn't have to switch the throttle over, but we will see how it goes first.

I'll post to say what happens but in the meantime I want to say thank you for your kind help.

Rebecca

If anyone is watching - we switched things over on the engines and managed to get the second one running for a minute - then the boss assembly for the blade actually sheared with a third of it coming off! As we need to get another we are taking it to a local company to handle changing it and changing the mowers over.

The information given has been amazing and we've been able to use it to fix a backpack strimmer, so thank you!

Rebecca