SV150 recoil

[Burnerman]

If the engine refuses to tick over then its a pilot jet blocked in the carburettor - nothing to worry about until you have time to sort it.
On full RPM the pilot mixture system is generally overruled so plays little part.
John

 

[ipbr21054]

I will take off carb in a minute.

Are you around on this group in say half an hour hour so i can ask where this jet is ?

 

[Burnerman]

Sure, but pics would help a lot......from the top of the carb, the main air intake (air filter side) and inside the float bowl, if you can.
John

 

[ipbr21054]

Ok got this off internet.

Carb looks the same.

Is pilot jet down that cylindrical tubee ?

 

[Burnerman]

What you see there is the white float, hinged by its pin and operating the needle valve to allow or stop the petrol flow from the tank.
The central tube contains the main jet, with a screw slot. Undoing that lets the jet out, but above that is the emulsion tube that emulsifies the fuel for smooth running.
The pilot jet, and drillings, aren’t shown there. I’ll need a shot from the top of the carb for that.
John

 

[ipbr21054]

ive taken carb off, i have removed the brass jet from that tube and i couldnt see through it.
I dont seem to get anything else out from that tube even when tapping it

 

[Burnerman]

You need to be able to see right through the main jet and the emulsion tube.....if you cant then its blocked.
The emulsion tube will have fine cross drillings which also need to be clear.
Pics would keep me on the right track!
John

 

[ipbr21054]

Ive now cleaned out the first piece of brass and now able to see through it.
A hard tap then allowed the tube to come out,this looked ok but sprayed it anyway.
Now all put back together & in the morning i will then wake the neighbours up as a bit late now.

Thanks for the advice>

Strange how it was blocked as i have a filter on it but anyway thanks.

 

[Burnerman]

No problem!
You have serviced the jets and emulsion tube that control the engine from over tickover to full speed.....the slow running or tickover speed is regulated elsewhere in the carburettor.
All simple enough once you have studied it for a while.
John

 

[ipbr21054]

Hi

I’ve got it started ok this morning and able to move it away from choke and it doesn’t stall.

having said that now I have the same rpm whether the lever is at tortoise or hare ?

I’ve moved the cable slightly forward and back to see different styles of running but still no low rpm say tickover.

Seems to be the same no matter what

 

[Burnerman]

When you operate the throttle lever, does the cable move at the engine end?
John

 

[ipbr21054]

Yes it does

 

[Burnerman]

It sounds like there is a linkage adrift on the carburettor, or one that hasn't been fitted correctly.....its quite easy for these to jam, and hold the throttle butterfly wide open.
See if you can move the butterfly by hand.
John

 

[ipbr21054]

I can move it by hand.
I will take it off again and see if anything is different.

Thanks for your time,ive also purchased a small on / off tap to stop the fuel.
Now i need to see where to put it like as you say not much room and things get caught up etc

 

[ipbr21054]

Removed and replaced now running fine and 2 lawns cut this afternoon.
The cable needed moving slightly and all ok now.

BUT

I have a fuel leak.
What is supposed to stop the petrol running out the carb.

some times when not in use I unscrew the cap. When I’m using it the engine burns the fuel so the leak is very minimal. When stopped then you can smell and see it dripping.
It drips from the back of carb when it mounts to engine.
See photos attached.

3 questions for you.
Does the paper gasket fit between black air filter box / carb OR carb to engine ?

I ask because it was between air filter / carb. just making sure it’s in the correct place.

I think the petrol is leaking from the small whole in carb where it mounts to engine. In photo supplied the hole is say top left of carb around 11 o clock mark.

I understand the black o ring seals against carb but the fuel coming out of this hole runs behind or down the side of it. The seal actually seals in the recess of the carb NOT this hole.

So why does it do it ?

I removed the white float in the carb and the needle jet moves fine so it’s not as if it’s stuck open etc.
One thing after another but good learning curve.