Mighty Moke - On the Road again!!!

[Biggles]

1275 Casper

     If you look at the thermostat housing the 2 studs closest
to the rocker cover are at an angle. 998/1100 engines those
2 studs run parralell to the end of the rocker cover. The angle
ones are a 1275 head. The only difference is some 1275 heads
have been fitted to 998/1100 engines. but  they need some
modification to the block for that and aren't very common.

              smoken

[Pete Power]

Thanks Smokey yep 1275.
Terry my Gregorys says 46-56 and Point cap of around .015" (from memory) book at home I'm at work!!!
My point gap is already at bottom of range to achive 48deg. There were two differenet ranges listed. I think one lot for UK models and on for Late Model Aust?

[casper]

Smokey, what set me off were the 'ribs' on the lower part of the engine block, I think I remember Terry saying that it was unique to 1275's (?)
There was no way I could pick it from the head, didn't know about the angled bolts.

Just quickly, can you tell a cooper motor from a plain?

casper

[Newie]

Hopefully won't just add to the confusion Casper, but aren't the ribs on the block to do with it being an A+ engine?

Newie

[Terry]

Hi,

Newie is correct, the extra 'ribbing' in the casting suggests it is a A+. Also you can see the mouting point for the Alternator is closer to the radiator which is another A+ feature.

Terry

[casper]

I was close....

Casper

[Nickomokeo]

can you tell a cooper motor from a plain?

Casper,
The cooper motor drinks petrol and makes a mini go fast, a plain is a level tract of country.
Forever helpful icko

[Pete Power]

Little more of a play last night and after tweaking Air/Fuel mixture nut running a lot better.
I think it was probably way to rich.
What is the correct way to do it??
I wound my nut in/up several turns until engine revs increased, i then backed it off a couple of turns. How do you know when it is right?

[mattsmadmini]

Adjusting The Mixture:

Note: in the following procedure, one "flat" is the basic increment of adjustment, and refers to 1/6 of a turn of the mixture adjusting nut.
This corresponds to the flat faces on the nut.

peer down the throat of the carb and turn the mixture screw while watching the top of the jet. Remember that moving the top of the jet up will lean out that carb, while moving
the top of the jet down will richen it.

1. Shut the car off and loosen the choke linkage nuts.

2. Adjust the mixture nuts (screws) fully lean.

For separate float-chamber cars, this means raising the mixture nut all the way up against the bottom of the carb (or rather, against the spring). For HIF carbs, you can try turning the screw while looking down the throat to see which way the jet is moving. In either case, the idea is to zero out the jet: raise it all the way up in the bridge.

3. Now drop the jet an equal amount -- two full turns for HS-type carbs, two full turns (I believe) for HIFs. Then start the car.

Note: In the following step, you might want to consider adjusting the carburetors one-half a flat too lean, as the mixture will be enriched when you put the air filters (which restrict air flow) on at the end of the tuning process.

4. Raise the lifting pin (or use a screwdriver if you don't have the pins) so that the piston rises no more than 1/16". Listen to the engine's exhaust note and compare it to the following conditions:

- If the exhaust note rises and stays high till you drop the piston, this carburetor is adjusted too rich. Turn the mixture nut one flat (one-sixth of a turn) up, moving the jet toward the bridge, then repeat Step 4.

- If the exhaust note falls and the car sounds as though it is going to stall, this carburetor is adjusted too lean. Turn the mixture nut one flat (one-sixth of a turn) down, moving the jet away from the bridge, then repeat Step 4.

- If the exhaust note rises briefly and then settles back down to something like the original RPM level, this carburetor is set correctly. When you have achieved this setting for both carburetors, continue with Step 5.

5. Tighten the choke linkage nuts so that the choke cable will pull an equal amount on both mixture nuts when you pull the knob.

6. At this time, I find I usually have to adjust the idle again because getting the fuel mixture right usually changes the idle speed. Since you know you have the throttles synchronized, I normally just adjust the idle without loosening the throttle linkage. The easiest way is to screw one of the screws out till it doesnt' even touch the throttle stop, then use the other to get the idle speed right. When that's done, you can screw the other stop screw down till it just touches the stop on that carb and you're set.

7. Replace the air filters and go for a test drive!
 


Thank you BIAM

[Pete Power]

Thanks matt,
Sounds easy?
In Point 4 it refers to Raising lifting pin. Can I assume this is the Piston and I unscew the plastic cap and lift piston 1/16".
Does the oil level in Carb affect any thing here?

[Terry]

Thanks matt,
Sounds easy?
In Point 4 it refers to Raising lifting pin. Can I assume this is the Piston and I unscew the plastic cap and lift piston 1/16".
Does the oil level in Carb affect any thing here?

Over the back of the body on the fuel bowl side you should see a pin, looks like a nail with a spring around it. Thisis what is referred to as the Lifting Pin. If you push the pin up you feel it contact the piston and then take it 1/6" from the contact point.

Oil level affects the speed at which it rises and falls and so does the viscostiy of the oil you use.

For step 2 simply look at the brass tubes(jet tube) and turn the adjusting nut clockwise until both brass surfaces are flush. Step 3 is turn it down 6-8 flats for the HSU that you have.

I can't say I have ever bothered to undo the choke linkages but it would make turning the nut easier.

Terry
 

[casper]

Thanks Matt, nice description I'm copying that to put with my good guts info!

Casper

[moemoke]

Matt, I see you aknowledged BIAM, poor BIAM he's been banned on Ausmini.

I don't think he has joined up hear yet

[mattsmadmini]

Moe.... he was here long before he got onto Ausmini.... he PM'd me the other day on here actually 

[Pete Power]

FOR SALE 1 MOKE EXC COND RUNS LIKE CRAP
................not

Attempted the carby tune, couldnt work out the "Both Brass surfaces are flush" bit you mention Terry. Ended up dismantling Carby. Know where the Jet tube is it runs through the adjusting nut, Where am I looking. Anyway...
Wound adjusting screw right up and then backed it off as in step 3 and then played with adjusting pin and did get symptoms as described. Initially engine revs dropped so richen mixture. needed about 4 flats and got the correctly described -idle slight increase and then returned to original revs. Went for test drive, after fixing short from the reversing light switch cable that melted on the exhaust....
Idles beautifully but has a really bad flat spot. Every km or so I stopped and adjusted initially went lean by about 3 flats. No real change. Then went rich 4 flats(1 rich more than starting point.) I started noticing slight improvement so went another flat, and another and another, with no more improvement. At this stage I stopped for a beer at pub. (Just 1)
One more flat rich befoe heading home, about 1km form home tried to increase revs through flat spot and MM nearly stalled, pulled over and then idled fine but nearly stalled every time you tried to rev?? Drove home on idle.
Engine also seemed to be running a bit hotter than what I remember (about 85deg) could this be that the timing needs to be advanced.
So I guess a bit more playing tonight. Don't know how my burnt thumb knuckle will cope, bit tricky adjusting that nut in the dark. Thats why I needed the beer to soak my thumb in