Was driving my mum to the airport this morning, no problems. On the way home, the mini started coughing and spluttering under load.
I pulled over and checked to see if there was anything obvious. No leaks that I could see.
I pulled the spark plugs out and found that the condition of cylinder 1 and 2 were vastly different from 3 and 4. I have just put in new plugs last week, and took the mini for a solid drive yesterday down the royal national park without any issues.




The cleanest plugs are 1 and 2. usually they are quite black.

Can anyone point me in the right direction?

I am running a 45 dcoe weber on what I believe to be a 1380 (that was what it was registered as whe I bought it) elecvtric fuel pump, duel tanks...



Things I am thinking it could be at the moment is fuel starvation or head gasket...... Please any help would be appreciated.

Check the idle jets, emulsion tubes, main jets and air correctors are the same in both barrels.
I did a 1293 motor up for my wife's S replica that had used a 45 Weber, #1 & #2 pistons were pock marked like the moon from running lean. #3 & #4 were OK.
Carby had been sold but I bet the jetting was crook as stated.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Doc, Thanks for the response... how do I check the idle jets, emulsion tubes, main jets and air correctors.

I haven't worked with webers before. If I start pulling things off, how do I get it back to running condition?

It was running fine for a few weeks. The plugs were all identical in terms of colour before this morning... It was running a little rich (ie dark and black) then while driving this morning something changed.

im also having this problem, it starts after a while of pumping accelorator and choke out and sounds alright when idleing but as soon as you let the clutch out it loses all power and backfires.

its an 998 bored .080", 266 cam, and 1-1/2" su. can somebody give me any indication to what the problem would be.

thanks,

Leighton

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1975 Leyland Mini: 1060cc - resto/ ex-hsc project.

Take the round jet cover off the top. Inside there are 2 emulsion tube assys (at front) with 2 idle jet assys (behind).
Make sure L and R of each pair have the same numbers.
Air jets are on top of emulsion tubes, main jets at bottom.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Doc the numbers are the same:

F2 - 180

and

45 F9

were the numbers on the tube/screw things.

I have had a look a the distributor and leads to make sure spark is getting through.

While the engine was running i pulled the lead off plug 1. There was little change to idle and spark was getting through. When I pulled lead off number 2 plug, idle reduced dramatically almost to the point of stall. cylinder 3 was similar to 2 and cylinder 4 was similar to cylinder 1.

So to test the theory, I pulled 1 and 4 off together and there was little change. I pulled 2 and 3 off and the engine stalled.

Is this normal?

180 is the air correctors. Did you check the numbers on the main jets at bottom of the emulsion tubes??

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Doc,



From top to bottom the markings are 170 - F2 - 180. the bottom number is on the hexagonal screw in part.

Thanks for your help.

Simon

OK so the mains are 170.
Sounds somewhere near the money (if it has 36 choke tubes in it).

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Thanks Doc.

Well that eliminates the fuel issues I thought might be causing the missing. Now I am led to believe it could be a head gasket. Might look at pulling the head off tomorrow. Unless it could be something else....

What are the best type of head gaskets and where do I get 'em? Karcraft?

Cheers,
Simon

I`d be checking that the manifold hasn`t come loose from the cyl head , or the weber hasn`t come loose from the manifold etc first

& the jets may be blocked so blow some compressed air through them (Maje sure you hang onto them tight tho,,, don`t want them shooting off into the garden or across the road etc) or even try some fues wire (or similar) through them to make sure they`re clear

do a compression test & check your rocker clearances too

^ Leighton,,, maybe you have stuffed condensor &/or points

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

IMO the best 1275 gasket available at the moment (GT m will shoot me down though) is the BK450, from Karcraft.
It's my (and TheMiniMan's) favourite, no correspondence will be entered into.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

here here

or there there

whatever the case (of beer) be




best check the gear-shift mechanisim, just in case that`s what`s caused the problem

ok,,, i`ll stop now

hey at least the 3 of us (GTWoggsy, The Doc & Moi) know we`re all joking & friendly about it too hey??? Me thinks the 3 of us are showing our age & maturity don`t you think?

(stoopid remote shifts & copper head gaskets)



am not,,, are too,,, am not ,,, are too

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

check the compression before you take the head off....