Effective carb swap

[Station]

Have found a NOS carb that is equally 'jetted' to mine - which is a 1.2 sized engine one. It's a Nikki carb which was used on various Subaru's in the 80's.

I want to convert to manual choke as I find autochoke to be crap. The autochock on the existing carb has three or four dashpots and I'm not sure they work anymore. In fact, I think the carb gave up the ghost many years ago.

Is there anything I need to know (apart from getting a flange made up to match inlet to carb) before I unertake the work this weekend?

[Stixy]

Its quite satisfying to take off a complicated carburettor and fit a simple one , one of my favorite carbs is the weber 34ich  everytime ive used one of these its improved the car  the only problems ive had is underbonnet clearance 

 

are you making your own adaptor plate?

 

this stuff is good

 

 http://www.ebay.co.uk/itm/Aluminium-Flat-Bar-Plate-widths-from-80mm-to-4-many-thicknesses-and-lengths-/161064303572?pt=UK_BOI_Metalworking_Milling_Welding_Metalworking_Supplies_ET&var=460189345316&hash=item25802e3bd4

[Station]

Yes, I will make my own! Sure I have some of that somewhere.

[Station]

Got a carb off RR. Unfortunately, it was missing bits. Seller says it was 'spears or reperas'. I obv wanted a carb that didn't work to replace the carb that didn't work.

 

So through the week, I took the old carb to bits. Cleaned everything, even submerging screws and bolts in vinegar for a week and they came out completely grease free and spotless.

 

I put it back together again and apart from running like shit as usual, there were comedy amounts of blue/white smoke from the exhaust. I'm not talking about puffs, but a huge plume which meant I couldn't test it any further as I'd blind passing cars.

I didn't use a base gasket - I used that red gasket glue crap. Does it need a proper gasket (I kind've know this, but the only place that sells gaskets for these is America), as there is a separate port for coolant to keep the carb temperate.

 

It's the little bit at the back of the inlet:

 

 

Is this mixing water into the inlet as soon as I start it? Would make sense as it hasn't even warmed up yet, and the car is so clean there's no grease or oil to burn off.

I'm thinking the carb may work, but obviously the water is getting in and diluting the whole combustion effect.

 

Before rebuild:

 

[Stixy]

Get a big thick piece of gasket paper and make several gaskets and use them all as water is so near the inlet 

[skattrd]

I've had trouble getting gaskets for a few of my motors, so I bought some gasket material off ebay that does the job. The stuff I got came in A4 sheets that you cut to the shape desired.

Alternately there's the true shitters gasket that involves cutting up cornflake boxes.

[Station]

Is that the gasket paper? I found some cork stuff which seems better.

 

And is easier to cut.

 

http://www.amazon.co.uk/Custom-Accessories-37774-Gasket-Material/dp/B000BQMVBE/ref=sr_1_17?s=automotive&ie=UTF8&qid=1387142413&sr=1-17&keywords=gasket+cork

[skattrd]

What I got was a selection of material, paper, cork & some heat resistant stuff for exhaust manifold gaskets. I find it handy to have amongst spares.

[Des]

Hylomar is your bezzy mate anywhere around fuel, and do bear in mind that all modern cornflake boxes R shit, I used some a while ago, (from fancy gluten free cornflakes that tasted like cardboard), on an oil pump, tightened the screws down to buggery and a while later it's hanging off. Seems cornflake gaskets need a retighten moreso than usual.

Just remembered, last time I wandered up the road to buy gasket paper all they had was some packet with card and exhaust gasket for about £20 and too small for me, too big for the vendors arse where I suggested it go, went in charity shop on way back and bought an old Monopoly game for the box, 50p, proper 1970s cardboard, thick as a labradors ear and probably crawling with asbestos.

[Mr_Bo11ox]

Did you clean up the mating surfaces before lashing it back together?

 

Also does it run OK when warmed up, i.e. when the autochoke is no longer doing owt?

[Station]

Haha, would never use cardboard!

Yes, all mating surfaces where cleaned up, they're flatter than a witches' chest. Autochoke is rubbish on these - it has two small dashpots (or whatever the non-American term is) and a big one. In fact, the whole choke is rubbish. I think water IS getting in from that coolant port into the inlet as it's never done this before. When I bought it off WillSwitchEngage, it was running OK to be honest, but since I put redex in the tank it's gone even worse. And when I took the carb off to, ahem, 'repair', it's only been driven twice, and the last time it cut out at the traffic lights in rush hour traffic, and then three times getting home. In theory, the carb should work as the needles are fine, there are no leaks, the float is OK, blah blah.

[daveb47]

I would think that water feed is for autochoke & therefore not needed without it.

[Station]

Autochoke has an electrical heating element in it.

[Station]

Right then, bought some cork gasket, replaced the lower gaskets. Also replaced the top gasket as when I put it on its side fuel came out, it was completely perished. Put the carb back on and it ran quite well, apart from MORE smoke from the exhaust, and when it cuts out, a cute little piff of smoke from the carb.

I take it this is running rich slightly? There's an idle screw and a mixture screw. These don't make much difference. I doubt it's the timing and I can't check as the idle climbs merrily through the thousands.

I'm clueless now, why is it doing this?

[Des]

If there's no air leaks and the mixture screw is ineffective then maybe a blockage in the idle circuit, and it's running on the main jet / throttle alone, wont be good at low revs, or something damaged / missing in the idle circuit, causing a rich mix, again wont be good at low revs, look for damage from overtightened mix screw, air bleed jets kind of thing. Not stale petrol is it?

[Station]

I found out the little ball bearing under the plunger (which is somehow connected to the chamber next to where the float is) had done a runner at some point. I remember putting it in (it's under a spring, which is under a plunger attached to the throttle linkage), but I now see it's not there and FLOODING the float chamber.

I've been shopping for ball bearings this morning, but unfortunately, and to my surprise, nobody wants to sell ball bearings individually. I would have thought a shop as well stocked and helpful like Halfords would have a whole department dedicated to ball bearings. However, I have found a place that can sell 1000 ball bearings for £35, which should come in handy if I lose the ball bearing 999 times (which I estimate is the amount of times I'm going to have to take the carb in/out of the car).

Actually, I think this little 2mm wide steel ball is the missing link between working and not working.

[Station]

Christ! I bought a very small bearing today - it has 7 2mm bearings inside, so take the rubber cover off and take the bearings out!

Expect they're ROLLER bearings!

Argh!

 

Go through every switch I have in my garage to see if there is a bearing in any of them! NONE!

 

Remember Astra door handle locks have a very small bearing in them. Four handles prove they have not - whereas one proved they did - a 2mm ball bearing in my possession! WAHEY! HAve wrapped it up in about five rolls of toilet roll.

[tooSavvy]

 

Hmmm... I had a full set of TAPERED rollers + 2 halves. Dealer wound the nut up 'well tite' and 'log splitter-ed' the weakest one [replaced under warranty & went again....]

 

I'm a really slow learner  ..... fitted my own, from a local brg shop, and told the dealer to F**K OFF touching them, next service!! never had a problem since...

 

TS

[Mr_Bo11ox]

go to a bicycle shop, I bet they'll have some bearings

[Station]

Yes, thought of that, but the ball bearing from the Astra's door lock fits A TREAT.

 

The car runs now, and starts sometimes. Seems to be overfuelling a li'l bit. Minimad was checking for a spark with the spark plug near the spark plug hole and a huge pillar of flame shot out (so the sparks are working fine).

 

It needs a spring to keep the throttle closed as the idle is INSANE. Think it had one at one point? Holding the throttle closed on the cable lever reduces it to a respectable level under 15,000rpm.

 

It's MUCH better than what it was now though.