OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Tech Talk carby leaking fuel - mechanically challenged :-)

I think you'd have to be very lucky for that to work. The seat is more or less a piece of tubing pressed into the carburetor body. The B&S-recommended process tries not to expand the (fairly thin-walled) seat, and extracts it by running a screw-thread through its central hole, then having the screw extend past the end of the seat so it can push against the carburetor body at the end of the blind hole surrounding the seat. This applies a purely axial force to extract the seat. An ezy-out is intended to remove screwed-in components, by unscrewing them. In the process it expands them considerably, which expands the hole they are in also. This may not matter with screwed-in components, but expanding a pressed-in component just makes it harder to get it out - and the ezy-out does not apply an axial force anyway, it just applies a rotational force.

I'd do this job by finding the size of the through-hole in the seat, and grabbing a fine-thread tap that has a root-diameter slightly smaller than that. I'd cut a thread on the inside of the seat with that tap, then run a screw with the same thread into the tapped seat and out the far side, thus using the B&S extraction process without needing their weird American screw. I hope whoever Nathan gets to help him will do something similar, if he doesn't have B&S screws readily to hand. Actually I'd do it my way even if I had the B&S screw: never follow the instructions if it's more fun to make something up.

As I was reading the first para of your reply I started to think of the process you discribed in the 2nd para - scarry

starting to think that someone could do well if they started a mail-in carby refurb business...

any takers?

Nathan, as a simple try-it-and-see option, you could revert to the main alternative and try to clean up the seat you have. You can do this by using an ordinary deburring/countersinking hand tool, very gently. These devices are cheap and have red plastic handles on a multi-tooth, 90-degree-included-angle countersink. To try this:
1. Set your carburetor up so is stably supported upsidedown.
2. Rest the countersinking tool vertically in the hole in the seat, using a square to make it exactly at right angles to the float bowl top gasket.
3. Rest one fingertip on the top of the handle of the tool, to hold it steady. Do not apply pressure, or you'll wreck the job (and the seat).
4. Rotate the tool by the handle, using two fingers of your other hand, without applying any vertical pressure. Just one turn is enough for the first try.
5. Remove tool, and use a magnifying glass to inspect the seat.
6. Repeat the whole process until you have a smooth, even edge all the way around the inner corner of the seat. The edge should be very narrow - barely visible - but of constant width all the way around. Any chatter marks or lack of squareness to the bore will mean you've wrecked your old seat.

worth a shot I guess. nothing to lose (but the price of the tool).

what does the 90 degrees refer to?

The included angle is the angle between the cutting surfaces on opposite sides of the tool. Countersink tools usually have the opposite sides either at 90 degrees to each other, or 60 degrees to each other. 90 is more common. So, it cuts surfaces that are each at 45 degrees (half of 90) to the longitudinal axis of the tool. That is probably a bit more than the angle of the sealing surface at the tip of the needle, which seals off the petrol flow when it rests against the seat. To give it a decent chance of sealing without needing a huge amount of force from the float, you want a narrow anular surface to be cut on the seat by the the countersink tool - as narrow as possible, but of constant width all the way around its perimeter. Of course it must be exactly aligned with the axis of the seat - a round needle can't seal an oval hole.

The kind of countersink tool you need for this job has about ten cutting edges evenly spread around it. That helps to keep it centered, which in turn helps keep it from chattering when you rotate it by hand.

learn something new everyday :-)

I will check in bunnings to see if they have one of these tools when I pass one next.

thanks
Nathan

I've ordered the carby kit, just waiting for it to arrive. Then I will ring a few mower places and find a helpful one that can take the seat out for me.

carby kit should be in today and I have a friend in the states sourcing the self threading screw and sending it over to me :-)

just don't like my options for getting someone else to do the job. I would prefer to get the right tools and do it my self.

Hi Nathan, It's always good to do things yourself and through your efforts with this prob, you may help another member that is having the same trouble.
Best of luck with it mate.

That's my thinking Darryl.. And when people say, "yeah I should have the tools for that"

It doesn't inspire much confidence

Nathan, it is a fairly simple carburetor, with parts easily available, and that makes it a good one to practise on.

There are limits to what is worth attempting: I once decided to clean out a very complicated car carburetor that was also obsolete and had never been sold in Australia (it was a Rochester 4-Jet, the predecessor of the well-known Rochester Quadrajet). It had 4 float bowls and more bells and whistles than an F18, but it worked miserably: it had tip-in hesitation, probably due to some kind of fault in the accelerator pump. I dismantled it, and lost the aluminium ball that was the accelerator pump intake valve. I went to the 'main man' on carburetors for an aluminium ball, and he refused to sell one: he wanted to do a full overhaul, which cost me a fortune. It did improve the hesitation problem, but at an outrageous cost.

You aren't likely to have any problems of that kind with a flo-jet: you can get the parts easily. In an emergency, you could even get another carburetor.

In an emergency I'll just post it to you

the more I do the more I learn and then I will understand how things work for next time there is a problem.... the only downside is the grass just keeps getting longer!!!

I think I might have a problem. Just opened the delivery from the outdoorking shop and the seat in the carby kit I have looks different to the seat that is in the carby. hmmmm.

From what I can tell, the seat in the kit is the one 3rd from the right on the top row in the picture
https://www.outdoorking-forum.com.au/index.p...mp;cPath=193_195_203&products_id=334

problem is that the seat in the carby doesn't look like that. the one in the kit appears to have a thread on the outside of it and has the lip on one end with a slot through it so a large flat head screwdriver could be used on it.

So either i have the wrong carby kit or someone has put the wrong seat in the carby in the past. Although the post from Grumpy with the illustrations showing how to replace the seat would tend to indicate I have the correct seat in the carby and the wrong one in the kit.

What looks like the correct seat is this
https://www.outdoorking-forum.com.au/index.p...mp;cPath=193_195_203&products_id=328

so maybe the carby kit doesn't come with the seat and that is some other part? or maybe the carby has two different seat options? sigh.....

Nathan, the object 3rd from the right in the top row appears to be one of the jets, not the seat. I don't know if the seat is in your kit or not, but the needle and its retaining clip seem to be there in the second row. I had been guessing that the cylindrical object below the clip, in the 3rd row, was probably the seat, but I can't see it properly and am guessing. I suggest you PM Bruce - this can probably be cleared up in a flash.

So I have finally done some more work on the mower. I got the special bolt to remove the seat which was actually pretty simple. I then pressed in the new seat.

the seat in the carby kit was wrong so I also had my friend in the US send the correct needle/seat kit with the bolt.

Installed the new needle and replaced the fuel bowl gasket from the carby kit. I then adjusted the "tang" so that the needle closed the seat when it was meant to... so all good on the flooding front :-) YAY

But alas, the bloody thing would not start. tried so long it melted the earth wire to the engine (fixed that with some thicker wire) but still no joy.

so out the with plug, connect to the lead and sat it on the chassis so it was earthed. cranked it over and no spark... had a new plug and it made no difference..

so perhaps the magneto is buggered. not sure how to test that?

Nathan

This being a ride-on mower, it has half a thousand delightful safety devices to keep us from putting our face in the blades then pressing the starter. Some of these devices work by triggering the magneto's kill wire: the wire that we ground to switch off the engine. So, there probably isn't anything wrong with your magneto, you probably have a displaced wire or a broken microswitch on one of the safety devices. You need to check the driver's seat, clutch, cutter engagement, and whatever other microswitches it has. My preference is to trace it all on the wiring diagram, but lots of serious techos just go to each microswitch and check its status. You can start by checking whether this is the actual problem by just establishing whether the kill switch wire from the magneto is grounded. If it is, try temporarily un-grounding it by disconnecting it. Of course, be very careful: without that device operating there is nothing to keep you from having your foot or fingers in the cutters when you crank it - and no way to stop the engine. Once you establish that it will run with the kill switch disabled, you have to trace the circuit, checking which switch is grounding it. You didn't try to start it without sitting on the seat, did you?

of course.. last time it was at the shop they hooked up the switch under the seat!!!! how stupid am I. don't normally have any of the switches enabled.. I'll just short that one out while I test and of course I will enable it again when I am back on the road (well the paddock anyway)

always the simple things.. my fingers are crossed :-)

well what do you know... it was the switch under the seat... I'll get the air filter back on and run in up for a while and see how it goes.

after all this starting I will need to put the battery on to charge :-)