Impco 300A mixer - Lean/Rich adjustment

[dom14]

Hi Guys,
I'm just about tune the fuel system of my GQ RB30(carby, dual fuel, manual transmission).
The LPG system is Impco 300A mixer+Impco modle L converter.
I'm just looking for some tips/advice and don't do's(precautions) for using the lean/rich adjustment on the Impco 300A mixer.
Thanx in advance.

[Bigcol]

Hi Guys,
I'm just about tune the fuel system of my GQ RB30(carby, dual fuel, manual transmission).
The LPG system is Impco 300A mixer+Impco modle L converter.
I'm just looking for some tips/advice and don't do's(precautions) for using the lean/rich adjustment on the Impco 300A mixer.
Thanx in advance.


DONT DO IT


unless you have a Lambda machine....................

[Bigcol]

DONT DO IT


unless you have a Lambda machine....................

EDIT


DONT TOUCH IT...............

unless you have the following
1) a Lambda machine
2) a Gas Fitter License of vehicles
3) an idea of what you are about to play with

definitely NOT a good idea Dom...........

take it to an approved authorised Gas service center fer fooks sake

reading a shed load of books and post on forums will NOT give you the necessary skill set to do the job
1) properly
2) Safely
3) without danger to yourself or others


there is a reason why people do Apprenticeships to learn things
the book only tells you less than half of it
experience teaches you the rest

[dom14]

Hi BigCol,
Thanx mate.
That's why I'm here. To Learn and share.
I have no intentions to fix cars for a living as it's beyond my time.
But, very much interested in learning to tune properly and share my experiences.

1)Don't have a lambda machine, so I would have to research how to get around that.
2)Don't have a license, but I'm still changing my water tap washers, as well as LPG work, as long as I can do it safely.(I do agree licenses are there for a reason, but also agree there are exceptions, like myself, who's more than happy to do it with great attention to the safety)
3)I'm here to get as much as an idea as possible, and you are right, reading alone won't work.

Safety won't be a concern with my detailed attention to detail. There's a better chance I can get hit by a car on the road.
But, the skill set, that's of course the issue.

1) Properly - yeah that's a concern until I know what I'm doing
2)Safely - That is not going to be an issue for me
3)Danger to me and other - That won't be an issue either, and there's zero chance for any danger to anybody else.

I'm not planning to do the tuning adjustment on the 300A mixer while the engine is running(at least not at this stage), so there's very little chance of any injury.

So, you know I'm gonna do it anyway, don't you?
If you're concerned, just PM me of what you know. I won't simply fiddle with any LPG gear/settings. I will first understand what I do before I touch anything.
I'm gone way pass that childhood curiosity to break/cut/dismantle things to learn.
This isn't a simple childish curiosity for me. I'm pretty serious about doing things by myself and take a lot of precautions.
Cheers
Dom

[dom14]

I think the real danger here is that I may screw up the tuning, rather than making it better as I don't have access to the gas analyzer gauges.
Safety wise, I'll be fine.

[Bigcol]

Safety wise, I'll be fine.

famous last words I fear.............

[Bigcol]

Dom,
I know you like to tinker around with your Patrol

great
love it
applaud you for giving it a go

however, you have been told in a few different posts, to take it to get it done properly and not to stuff around with it

thats not because we think your useless, or stupid
its because if you take it to someone who knows what they are doing, they can set the freaking thing up properly, and then you WONT have to endanger yourself
just do the basic's to keep it ticking along

not trying to smash your bubble, but man...............

[dom14]

Cool, mate. I understand where you're coming from. You're not trying to discourage me, but giving me sound advice.

I promise you I wont stuff around with safety precautions.

But, I don't know whether I can improve the tuning/performance without having access to a gas analyzer.
For that reason, if I go ahead and change the fuel/air mixture & the idle screw setting on this Impco 300A mixer, I will mark everything the way it is,
so I can put it back the way it was before.
You gonna have to trust me that I won't fiddle with any safety precautions.

I'm planning to dismantle the mixer anyway. That's just to find out whether the diaphragm is in good nick or whether I need to replace it.

There's will be zero chance of me getting any cold burns.
I have two fire extinguishers and water hose ready(never had to use them).

But, there's a chance I can screw up the tuning and performance. So, I'll approach with lot of precautions on that as well.

Cheers

[dom14]

When all this is done, I'm willing to and see the gas dyno.
I did the same thing with the rear diff. Took it to a diff fella to go make sure I haven't screwed up the backlash and the preload. :D
But, I'm happy to completely leave the tranny's to pros. That's way beyond my time and muscles. :D
Won't even bother touching diffs anymore either. It's a time killing specialist exercise better left to a professional. :D

[garett]

apart form the safety you can cause damage to the mixer and intake pipe etc. due to backfire, without a lambda your stabbing in the dark. this system is not the easiest to tune but holds its tune for quite a while without the need for adjusting.

[dom14]

apart form the safety you can cause damage to the mixer and intake pipe etc. due to backfire, without a lambda your stabbing in the dark. this system is not the easiest to tune but holds its tune for quite a while without the need for adjusting.

Thanx mate. It's been backfiring like hell for a while and then started misfiring and occasional backfiring again until I did lot of work on the ignition system.
Chances are that the diaphragm may not be in it's best condition after going through a lot of backfires.
So, overall, it's been through a lot of backfiring as it is.
I'm not too sure about getting the tuning of the LPG mixer right by myself, but I would have to open it up to see the diaphragm condition.

Is the importance of having a lambda is the same as the importance of having an air/fuel mix analyzer (or dyno, etc) for the petrol carby?!!

[Bigcol]

with it back firing, it may have "blown" one of the lead plugs out of the Carby

that would NOT help.......

[dom14]

with it back firing, it may have "blown" one of the lead plugs out of the Carby

that would NOT help.......

Thanx BigCol,
During my first carby rebuild, the lead plug thingy shows in below pictures dropped out when I was dismantling the carby.
I wasn't sure exactly where it came form, but pretty sure it dropped out while I was opening the float bowl compartment.
Please have a look and see if that reflects one of the lead plugs that you were referring to above(hoping you weren't referring to welch plug type plugs on the outside body of the carby)
I also couldn't find any "balls" inside the carby, even though the rebuild kit came with a few.
This was interesting 'cos when I was doing the spare Nikki RB30 carby, I found a spring loaded ball in one of the vacuum/fuel passages. So, I'm not sure whether original Nikki carby is a "ball-less" one or the ball(s) were simply gone missing, but somehow it's still keep rolling!?