What’s wrong with this rubbish?

[sharpasaspoon]

Hi, long time lurker, first time posting.

I was given a cheap 24 ltr compressor, you know the type! I’ve fixed the cylinder head gasket, replaced the capacitor (it didn’t actually need it),

It runs but slows, struggles and stalls at around 25psi. Any idea how to fix? I know it’s probably not worth it but I’m stubborn!

Thanks.

 

[tom2207]

petrol power ?

 

[dan treg]

pictures always helpful

 

[tom2207]

if its petrol ,,, fresh fuel and check the chokes off ,,,

 

[Wozzaaah]

He says he's replaced the capacitor so sounds like it's electric.

 

[tom2207]

yep , your right , it was the stalls and head gasket , that fogged my thinking .

 

[Seadog]

I know it’s probably not worth it but I’m stubborn!

Join the club

 

[tom2207]

how long does it take to get to 25 psi ,, and will it keep running if you leave the drain valve open ...
thinking sticky valve here .

 

[voipio]

Does anything get particularly hot? Is there oil in the crankcase? Was there anything that seemed "out of place" or not quite right when changing the head gasket? Shorted motor turns would cause loss of power, so would lack of oil, or a problem with the valves.

 

[sharpasaspoon]

Thanks for the replies.
Sorry I didn’t add a photo that was dumb of me. I tried adding a video clip but it kept on telling me it was too large even though it was a few seconds long.

Here is a Screenshot of the video.
Don’t try playing it please

It takes 25-30 seconds to get to 25psi. Seems strong and ‘normal’ at first then slows and stalls, motor buzzes at that point so I shut it down quickly.

The oil is good, compressor doesn’t get hot, electric motor is warm. It keeps running if the valve is open, as in dumping the air. Nothing seems out of place. The head gasket had a tear between the chambers and was blowing back through the intake filter, fixed now.

 

[tom2207]

Thanks for the replies.
Sorry I didn’t add a photo that was dumb of me. I tried adding a video clip but it kept on telling me it was too large even though it was a few seconds long.

Here is a Screenshot of the video.
Don’t try playing it please

It takes 25-30 seconds to get to 25psi. Seems strong and ‘normal’ at first then slows and stalls, motor buzzes at that point so I shut it down quickly.

The oil is good, compressor doesn’t get hot, electric motor is warm. It keeps running if the valve is open, as in dumping the air. Nothing seems out of place. The head gasket had a tear between the chambers and was blowing back through the intake filter, fixed now.

was it a two stage piston by chance

 

[sharpasaspoon]

I’m sorry Tom I don’t know what that means

 

[tom2207]

just a standard looking piston , like a car engine ish
im guessing that if it runs ok without a load , ie drain valve open , the problems on the electrical side .. but if its not blowing fuses then its beyond my knowledge.

 

[sharpasaspoon]

Just looks like a standard piston, not blowing any fuses. Thanks Tom.

It seems to be as if it has a ‘weak’ electric motor, if you can have such a thing.

 

[tom2207]

thats my thought ,,, but you need the sparky type guys for that , im more mechanical . But I thought if that was the case the amps would go up as it tried , and then would blow the fuse ,,, or smoke.
Over to some one else.

 

[octo0072000]

you replaced the start capacitor has this got a second capacitor called a run capacitor ? if so change that as well

 

[Alan Reynolds]

I assume that the cylinder head had small metal reed valves, one inlet and one outlet. I wonder if it is leaking back on the outlet and that's stopping it when it reaches a certain pressure. Is the non return valve ok? What value was the cap?

 

[chrisg3103]

Maybe something weird going on with the check valve. Possibly sticking and backing up the pump when the unloader closes

 

[sharpasaspoon]

It has only one capacitor unless the run capacitor is tiny and hidden.

The cylinder head cap has a v or u shaped steel reed vale between the chambers I didn’t see another but I’m not saying it’s not there just I didn’t see it. I’ll take the head off again and see what else is there. And pictures of course!

The non-return valve where it splits into the tank and the switch is good

 

[sharpasaspoon]

I took the head off and it all seems ok, famous last word. As they say, a picture paints a thousand words. You can see the gasket repair I did, it’s the black section.