lawn mower engine

tommyboy26

Not sure if this is the right place for this so if not could a Mod move it

i got a second hand lawn mower that's body was in very very bad shape. I only wanted the engine so i removed the engine from the body.

i was told the engine should be fine that it need to be serviced and cleaned up.

so i drained all the oil and petrol and put fresh fluids in. i replaced the spark plug as the one in it was rusted. i gave the engine an overall clean down but the problem is the engine wont start.

I'm looking for any ideas of what i should do to get it running.

a couple of things i should note:

1) my knowledge of engines is ok but not amazing
2) the carb on the engine should have a box attached but it is missing(see photos)
3) as the engine is no longer attached to the body of the mower, the cables that ran to the handles from the engine are no longer attached.
4) the engine is going onto a go kart not back on a mower

I know it is hard to know without seen the engine in person but if anyone could point me in the direction of what i should check i would greatly appreciate it

my3cents

All you are missing is the air filter. No way can you run the engine for any lenght of time without that. OK to try and start it though.

Try pouring a drop of petrol into the cylinder with the plug removed, replace the plug then pull it over if it does't fire then its more likely a spark plug issue that needs solving if it does fire then its a fuel/carb issue.

Edit> There will also be a spark defeat switch (on off switch) and probably a brake built into that lever on the side last picture. So you need to devise a way to pull that towards where the control cable would normally attach. Bit of rope and a washer work, you tie the rope to the lever then the washer goes on the rope and you have to fiddle around tying a knot in it to hold the washer in place so it can be pulled back and held in the notch where the cable would attach - can be done.

tommyboy26

my3cents wrote: »

All you are missing is the air filter. No way can you run the engine for any lenght of time without that. OL to try and start it though.

Try pouring a drop of petrol into the cylinder with the plug removed, replace the plug then pull it over if it does't fire then its more likely a spark plug issue that needs solving if it does fire then its a fuel/carb issue.

thanks for your reply.

just to clarify am i removing the spark plug and pouring a drop of petrol through the gap where the spark plug goes?

my3cents

tommyboy26 wrote: »

thanks for your reply.

just to clarify am i removing the spark plug and pouring a drop of petrol through the gap where the spark plug goes?

Check my edit first if you don't have that lever pulled back there will be no spark and there may be a brake on the flywheel.

tommyboy26

my3cents wrote: »

Check my edit first if you don't have that lever pulled back there will be no spark and there may be a brake on the flywheel.

there was a brake on the flywheel but i removed it as i wont need it on the kart.

the two levers on the side open the carb, one opens the front part of the carb and the other opens the more inner part of the carb if that makes sense.

which one should be opened/closed for the engine to start?

my3cents

Mower engines have to have certain safety features. Few if any of the size you have have a throttle anymore the lever in the last picture (your bottom link) just needs pulling back to remove the brake (no longer an issue) and to make the circuit that allows the spark to fire. The engine will be fixed revs but can be modified with a throttle cable current revs will be the max allowed on a lawn mower.

The levers you mention (second picture) are for the choke, choke to start and a governor arm which you don't touch at this stage. Later on you should be able to attach a throttle cable to part of the governor system but just to test the motor leave that well alone.

tommyboy26

my3cents wrote: »

Mower engines have to have certain safety features. Few if any of the size you have have a throttle anymore the lever in the last picture (your bottom link) just needs pulling back to remove the brake (no longer an issue) and to make the circuit that allows the spark to fire. The engine will be fixed revs but can be modified with a throttle cable current revs will be the max allowed on a lawn mower.

The levers you mention (second picture) are for the choke, choke to start and a governor arm which you don't touch at this stage. Later on you should be able to attach a throttle cable to part of the governor system but just to test the motor leave that well alone.

so do i need to reconnect the lever for the brake to allow the spark to fire?

my3cents

tommyboy26 wrote: »

so do i need to reconnect the lever for the brake to allow the spark to fire?

Yes, its a dead mans handle, but you can jury rig something to pull the leaver back, but you also need to be able to release it to stop the motor. Later on you can hard wire a switch in.

tommyboy26

my3cents wrote: »

Yes, its a dead mans handle, but you can jury rig something to pull the leaver back, but you also need to be able to release it to stop the motor. Later on you can hard wire a switch in.

thank you very much i will give it a go

CJhaughey

tommyboy26 wrote: »

thank you very much i will give it a go

That engine is the wrong orientation for a go kart you need a horizontal engine output the one you have is a vertical shaft.

tommyboy26

CJhaughey wrote: »

That engine is the wrong orientation for a go kart you need a horizontal engine output the one you have is a vertical shaft.

can i not just turn the engine on its side?

Wildly Boaring

tommyboy26 wrote: »

can i not just turn the engine on its side?

No

Edit to expand
Any normal mower engine is 4 stroke. So turn on it's side and oil all sitting in wrong place. Will not lubricate anything. Give it 1 or 2 mins she'll seize.

The drive is out of side of engines like those for concrete mixers. Hard to source

Wildly Boaring

For a kart you want the engine (and drive chain) off an old motorbike.

Pretty straight forward from there. Get something handy like any old Honda cub 50, 70 or 90.

Ideally an old kickstart one. Then weld drive sprocket to back axle, and alter your gear shifter to suit.

Sort some brakes. No need for clutch on lot of these. Bobs your father's brother

gctest50

tommyboy26 wrote: »

can i not just turn the engine on its side?

Much easier get an engine from a moped, they've an auto clutch and gearbox - just put a sprocket on instead of the rear wheel and it's done - electric start n all

tommyboy26

Wildly Boaring wrote: »

For a kart you want the engine (and drive chain) off an old motorbike.

Pretty straight forward from there. Get something handy like any old Honda cub 50, 70 or 90.

Ideally an old kickstart one. Then weld drive sprocket to back axle, and alter your gear shifter to suit.

Sort some brakes. No need for clutch on lot of these. Bobs your father's brother

ideally that is what i wanted but was hoping to do this on an extremely cheap budget and i got the lawn mower engine for free

GreeBo

You could try a bevel gear but it might not be worth the hassle

Wildly Boaring

tommyboy26 wrote: »

ideally that is what i wanted but was hoping to do this on an extremely cheap budget and i got the lawn mower engine for free

Had 3 karts growing up. All done this way. Far handier and several advantages

Kickstart means no battery

Gears mean less strain when taking off

Old Honda and Kawasaki engines v reliable

As above very easy to do. Just make sure to rip mountings and fuel tank from donor bike. The mountings have adjustment to keep drivechain tight. V important

John368

If this is off a rotor blade mower, usually there will be no separate flywheel as the blade will act as the flywheel. Hence if the engine is removed from the mower, it will have to have a flywheel fitted before it will work. However if a lack of a flywheel is all that is wrong with the engine then you would get the engine attempting to start. In fact you will probably get it kicking back fiercely - not very nice and quite dangerous as the kick back force on the pull cord could cause injury.

If there is no sign of life coming from the engine, the most probable cause of failure is a blocked carburettor jet. The carbs on these engines are very very simple can easily be removed, dismantled and put back together again if done systematically. The jet sprays fuel into the side of air inlet pipe on the downstream side of the choke flap. Find the opening which leads to this jet and blow into it. If you cannot blow through it, then it is blocked. To unblock blow into the air inlet while blocking off the air outlet. There are several Youtube videos on how to dismantle and rebuild these carbs..

CJhaughey

All these engines have a flywheel on the starter side, the drive side does not act as a flywheel it wouldn’t be heavy enough for a start.

blackbox

You could try using a belt drive with pulleys at 90 deg to each other. Belt will need to be fairly long. What type of reduction gear are you planning to use?