Auto Choke Doesn't

[GRW]

All very well but first you have to take the air filter out and find the brake cleaner and then start it and then put the filter and cover back on. It has electric start (when I find a battery for it) and will be lovely when I can just turn the key instead of all that faff.

Without a battery on it to operate the cold start unit - how can you be sure there's actually an issue?

Could it be that the unit activates with +12v off the ignition switch, and then releases with a 2nd 12v off the machine when running (in the same way the alternator light in an old mini works)?

 

[Prajna]

Without a battery on it to operate the cold start unit - how can you be sure there's actually an issue?

Could it be that the unit activates with +12v off the ignition switch, and then releases with a 2nd 12v off the machine when running (in the same way the alternator light in an old mini works)?

Ah, we took the battery off Mike's genny and used that. It's 13hp and not easy to recoil start at the best of times. Anyway I think there's a problem with the manual choke since pulling the choke lever doesn't close the butterfly.

 

[EBME2]

Sorry another link for you for what says it is the choke mechanism, is it similar?

Manual Choke Assembly For Honda GX240 GX270 GX340 GX390 8HP 9HP 11HP 13HP Engine Replacment Parts 16260-ZE2-722,16260-ZE2-723 - AliExpress 1420

Smarter Shopping, Better Living! Aliexpress.com

a.aliexpress.com

 

[Prajna]

Ok, took the air filter off and took some pics:

And yes, I can reassemble it differently. I can close the butterfly and reassemble but then I can't manually open it with the choke lever or I can open the butterfly and reassemble but then I can't manually close it:

I suspect that the vacuum servo, if that's what it is, controls the butterfly but dunno really.

That's it in the top right of the mechanism.

 

[Prajna]

Sorry another link for you for what says it is the choke mechanism, is it similar?

Manual Choke Assembly For Honda GX240 GX270 GX340 GX390 8HP 9HP 11HP 13HP Engine Replacment Parts 16260-ZE2-722,16260-ZE2-723 - AliExpress 1420

Smarter Shopping, Better Living! Aliexpress.com

a.aliexpress.com

That looks very much like the thing. I don't know how you people manage to find such obscure items! The question is, how is it supposed to all fit together?

 

[EBME2]

That looks very much like the thing. I don't know how you people manage to find such obscure items! The question is, how is it supposed to all fit together?

I’ve made a living out of being good at searching the internet for the last 20 years

Looking at yours and the AliExpress photos, yours the link to the diaphragm and the springy thing look a bit bent but could be an illusion. Does the diaphragm move if you suck on it? If your fairly sure it is that £16 delivered isn’t too bad, there was one on Amazon as well but was currently unavailable.

 

[Prajna]

I’ve made a living out of being good at searching the internet for the last 20 years

Looking at yours and the AliExpress photos, yours the link to the diaphragm and the springy thing look a bit bent but could be an illusion. Does the diaphragm move if you suck on it? If your fairly sure it is that £16 delivered isn’t too bad, there was one on Amazon as well but was currently unavailable.

I'll try that test tomorrow. I did notice that the tube on the servo is loose. It has one of those little wire clips. I can see myself upgrading that. It may be part of the problem but I was rather hoping to get a general idea of how the system is supposed to work.

 

[voipio]

The butterfly valve, shown in the images of the carb, is on the carb air/petrol mixture outlet side of the carb and is used as the throttle. It is in the wrong place to give an enriched mixture. Is there another butterfly, or other restriction (or the broken remnants of a restriction, or clues to where a restriction might have been) on the air inlet side of the carb?

 

[Prajna]

The butterfly valve, shown in the images of the carb, is on the carb air/petrol mixture outlet side of the carb and is used as the throttle. It is in the wrong place to give an enriched mixture. Is there another butterfly, or other restriction (or the broken remnants of a restriciton) on the air inlet side of the carb?

It is on the inlet/air filter side unless I'm mistaken.

 

[chrismac]

Without a battery on it to operate the cold start unit - how can you be sure there's actually an issue?

Could it be that the unit activates with +12v off the ignition switch, and then releases with a 2nd 12v off the machine when running (in the same way the alternator light in an old mini works)?

One thought if it is a fuel cut off, no power until its running then 12v supplied giving it fuel. If it does not start ever unless given some starting aid, probably petrol down the plug hole would achieve the same thing, apologies in a fashion for repeating this train of thought,

It would surly start if it was pulled over long enough without choke potentially if the choke is an issue,

Hope you manage to get a battery hooked up and try spinning it on the starter to see if it starts.

Good luck I'll watch with interest how you get the issue fixed.

 

[voipio]

It is on the inlet/air filter side unless I'm mistaken.

Ah OK, I see. I thought I was looking at the flange that bolted to the cylinder head.

 

[Prajna]

One thought if it is a fuel cut off, no power until its running then 12v supplied giving it fuel. If it does not start ever unless given some starting aid, probably petrol down the plug hole would achieve the same thing, apologies in a fashion for repeating this train of thought,

It would surly start if it was pulled over long enough without choke potentially if the choke is an issue,

Hope you manage to get a battery hooked up and try spinning it on the starter to see if it starts.

Good luck I'll watch with interest how you get the issue fixed.

It wouldn't start on electric start either until it was given some break cleaner.

 

[chrismac]

It wouldn't start on electric start either until it was given some break cleaner.

Thanks for that.

 

[Prajna]

Sorry for the delay in updating, been busy with other stuff. So, I took the vacuum tube off, connected another and sucked. Looks like the servo is working. Reconnected the tube, crimped the clip (will need to replace it at some point but it seems the servo is to open rather than close the choke, so it doesn't matter if it leaks a little just now). I reassembled the carb with the butterfly closed rather than open, stuck a 6v battery on and tried starting. No joy, so it seems to be something other than chokage that's making it reluctant to start. I'm off to the Algarve for a week, so I'll investigate further when I get back.

 

[Jack_K]

The solenoid on the bottom of the carb could be the fault. It doesn't entirely shut off the fuel but restricts it to prevent the backfire when shutting the engine down. On a generator it works a little differently to things which are only electric start. When the switch is in the kill position, it provides power from the charging winding to the solenoid until of course the rpm drops.

You could install a bolt in it's place to see if it is the cause.