hey guys so this is a fun one for u all to have a think about. I recently regoed a 74 clubman with a 998 in after buying it and doing a bit of a resto ( 2 pack respray and polish everything up, new carpet etc) I drove it to QT and around for about an hour after and ran fine, started to run a bit rough about 5 mins from home but got there no real hassle. Went to drive it a few hrs later and it started but then stalled as I drove out of the driveway and then refused to start. Had a play with it the next day and could not get it start at all, winding over and over. I figured it was electrical so pulled the dissy and had is professionally rebuilt and the points set and refitted it. When I finally managed to get it run after heaps of mucking around it will only run with the butterfly open most of the way and with the choke being fiddled on and off to keep it running. It sounds like a 2 stroke tractor that’s running on 3 cyl and I cant for the life of me figure out why… I have repaired or replaced the following

new 98 fuel and fuel filter – full tank to dilute any crap in tank – ran fine for the hour on this fuel, I checked fuel pump and it has good pressure
had the dissy rebuilt professionally, set timing both statically and fiddled with with motor running – no improvement
rebuilt the carb - 1 ¼ su with new shaft fitting snug and gasket set – no improvement
changed out leads and coil, checked leads are on right position about 20 times and have good spark at the plugs (am running ignition testers to prove it on each plug) – no improvement
pulled head and renewed head gasket, checked head for warpage(none) , checked and reground valves and set tappets at 15 thou both intake and exhaust, did comp test, around 110 – 120 across the board . – no improvement

I am not sure where to go from here other than upgrading the anchor on my boat (if u know what I mean. ) Where would u guys look to next? Does anyone on the gold coast have a known good 1 1/4 su carb I can borrow to eliminate the carb as the source of the problem? I feel like it has to be carb related but it seems weird that it would all of a sudden just start running like crap…
I’m located in Carrara if any kind soul wants to drop by and have a listen otherwise I am open to suggestions on the forum. pic added just because.

Mini experts assemble!!

Take the lid off the carb, and check the level. It should be about 2/3rds or greater in height. If not, fill the bowl up and then give it a try again.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Mixture? Or could be a variation on the problem my car had : viewtopic.php?f=2&t=88691

cheers,

Jacob

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'72 Clubman Van - 1022cc, 295 head, 731 cam - Daily Driver
'69 Morris 1100 S - Dinged by a bus, in shed under repair
'64 Morris 1100 - Early 1100, long term project

Check the inlet manifold and gasket for air leaks.

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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.

thanks for quick replies, bowl is a bit over half full when i pull off cover and if i pull center out of carb i can see fuel on the seat so it seems to be getting fuel. also pulled the fuel line off the intake of the fuel pump and fuel flows freely out and onto the floor so i do not believe there is a blockage in the tank or fuel delivery line. have fitted a new inlet manifold gasket with the head gasket renewal. any other suggestions?

Might be worth doing a compression check. Could be a burnt valve after along trip?

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Now with 2 extra ports!

Sounds like An air leak on inlet manifold.
I had similar problem and eventually found the inlet manifold had been broken due to a previous accident

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1969 Cooper "S"
1967 Mini Deluxe
1973 Clubman Van (the fleet spare)
1978 ex 1275 LS ("Wizard" Eaton Supercharged)
2015 HSV GenF GTS(occasional drive & tow car)
2019 MINI F55 Cooper S

On my old Clubman I had a later type manifold with the pipe for the anti-pollution gear on it. I plugged this with a plastic blanking plug.

A couple of times this plug fell off and the car exhibited similar symptoms to those you've described. Had me scratching the head the first time it happened.

Second time was when the Son was driving and had it towed home. I found the plug sitting under the bonnet, put it back on and had the thing running again before the tow truck drove away. He wasn't happy!

My guess is a sudden massive air leak in the inlet manifold maybe from a cause like mine?

Good luck, Pottsy

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Smile Up at The Trucks!

valves have all been reground as part of the head gasket replacement, i did a comp check after putting head back on and the comp was between 110 - 120 across the board. mine does not have a anti pollution hole in manifold but from the sounds of it the general consensus is an air leak causing it to run lean. i will pull the manifold off again and recheck for cracks or holes. i appreciate the input from everyone and will keep u posted.

How does it run with the fuel filler cap off?

haven't tried it with no fuel cap although the fuel flowed freely out of the steel line when i puled off the hose to the fuel pump. just pulled the intake manifold off and checked for cracks, nothing visible and i have used new gaskets between every mating surface. any further suggestions?

Have you replaced the plugs?

yep new plugs fitted. i ran it again this arvo and it would chug away with the butterfly way open so i wound the bottom needle nut way down and it will at least idle now with the butterfly in normal position. noticed the fuel running into the fuel filter is only a trickle now so maybe the pump is slowly dying. will install an electric fuel pump and see if that solves the problem, at least we are making progress! thanks for the input so far gents!

Fill the float bowl manually then start it. If it runs `normally' then it's the fuel pump has carked it.
Probably the little valves in it have worn out.

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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.