Running rich on a H2 carburettor

[Morrisminormo]

Hi every one,

I'm a proud owner of my 3rd Morris minor mo, she is a 1957 black 4 door saloon. I picked her up on Saturday and drove 230 miles perfectly with close on to 50mpg, however I have since used it daily for work ( 17 miles each way on B roads ) and I have been getting 25mpg, I have screwed the mixture nut up a flat at a time to lean her out but not much has changed, infact I am now fully adjusted up to lean. The car starts every morning perfectly and I don't have to use choke, which also confirms running rich, do you think the needle needs replacing? I nearly just ordered a new old stock H2 carb from East Sussex minors for £200 but I would rather try and sort this issue out. If you could please advise me I would be truly helpfull.

Ps if you would like to see a video of my car please click the link below

http://youtube.com/watch?v=aCotQk_1ji8

Cheers

[bmcecosse]

£200 for an H2 carb??? Are you mad?? Welcome to the forum by the way! If it drove 200+ miles giving 50 mpg - it is NOT running rich... However, in fact that is unbelievable economy - must be something wrong with mileometer or gauge accuracy. . 25 mpg on a stop/start commute is much more realistic. What colour are the spark plugs?

[Morrisminormo]

£200 for an H2 carb??? Are you mad?? Welcome to the forum by the way! If it drove 200+ miles giving 50 mpg - it is NOT running rich... However, in fact that is unbelievable economy - must be something wrong with mileometer or gauge accuracy. . 25 mpg on a stop/start commute is much more realistic. What colour are the spark plugs?

Hi not mad just stupid

I got distance from GPS the speedo works but probably out a bit, I did a steady 55 all the way back on a tank. Half my journey is stop start the other 40mph. I think yesterday I got 30mpg, I've been filling it up to the brim at the same petrol station daily and working it out from there.
How come my car is still running Nd starting from cold with no choke? With the adjustment screw fully adjusted? On my previous minors if I turned it say 4 flats to lean it would run hot and cut out on occasion.

I think if I could get it a little leaner it would be perfect. The plugs were a little brown, when I got back I changed coil, plugs leads, cap, etc

Thanks for your response

[bmcecosse]

It's NEVER the coil! Put the good old one back on. New coils are v unreliable...By all means carry it as a spare, but you will never need it! What may be happening is that the float valve can be leaking, or set slightly too high - when running along at steady speed this is not a problem - the petrol is used up by the engine. But when running slowly/stop start and starting from cold - the overflowing fuel causes a rich mixture. When you switch on from cold (without starting up) - does the pump tick a couple of times and then STOP. Or does it tend to tick away regularly?

[Morrisminormo]

I brought a Lucas coil from East Sussex minors, my car had side entry distributor and I changed it with top entry so can't use my old coil, different fitting for my new leads, , the pump ticks on average every other second in traffic, does that sound too much? In the morning with engine off it only tucks a few times until its pressurised so to speak.
What would be my next port if call? I was going to get new needle tomorrow?? Do you think that is pointless?

Many thanks

[bmcecosse]

The 'Lucas' coils are not what they used to be......put the old one back on - change the HT lead if needs be... It's not the needle.... I dare say a new JET may be a good idea on a carb of that age. If from cold it ticks and stops - then the float valve is fine. You could check the level - take the bell + piston off - and look at the level with pump ON. It should be a little bit below the bridge - if it's 'right there' at the bridge - I would drop it down by an 1/8" or so by bending the levers in the float bowl lid down slightly.

[Morrisminormo]

Thanks for that, I will have a look at that tomorrow, I will order jet, Do you think with new jet would allow my mixtuer adjusting but to actually work like it should?

I appreciate your help

Rich

[Morrisminormo]

Just ordered carb rebuild kit, they don't sell a jet singularly, jet £6 and kit £32 so not to bad

[bmcecosse]

Why would it need a rebuild kit?? I would just have bought a jet. The jets do wear over the years - increasing the mixture which can be adjusted out to an extent. But the time comes...... Also check that the needle is set correctly in the piston - with the shoulder flush with the base. Item 33 http://www.moss-europe.co.uk/Shop/ViewP ... exID=17080 By changing 'everything' with a so called rebuild kit - you will have to start from scratch again setting it all up.....

[mike.perry]

My solution to the problem would be to fit the later HS2 carb unless you are determined to keep it original

[Morrisminormo]

Morris minor center Birmingham don't sell individual jets only the kit, so basically having kit just for jet. I wanted to get it done this wkend as I'm off, otherwise would of ordered jet from else where.

Using the later hs2 would be fine?? If so perhaps buying one of those would be simple fix. Are there any issues using hs2 with 948cc?

Thanks

[bmcecosse]

Your car did (a rather unbelievable ) 50 mpg........I would be changing nothing!! Yes - look for an HS2 by all means - but there is no real 'performance' improvement - and your very expensive 'rebuild kit' will be no use......

[Morrisminormo]

Just got I'm my car and pump is constantly ticking! Without engine on! It's more obvious now, must be getting progressively worse so does that mean float valve sticking??

[Morrisminormo]

Just got I'm my car and pump is constantly ticking! Without engine on! It's more obvious now, must be getting progressively worse so does that mean float valve sticking??

Very strange, just got home from a hours driving, turned engine off and then out ignition on, no ticking of the fuel pump whatsoever ?? Could it just be float sticking??? If so where does the excess fuel go??

[bmcecosse]

Does sound like sticking float valve - possibly some dirt in it. Remove and clean. The excess fuel goes in the engine - but no problem as long as you are driving - but rich for slow moving/stopped in traffic etc. Presumably the rebuild kit includes a new valve??

[Morrisminormo]

Hi
I will look at float tomorrow, not honestly sure what's on the kit if I'm honest, have you ever striped and rebuilt the jet assembly?? Me and my dad are both gearbox builders but that doesn't necessarily mean we can do it??

[bmcecosse]

Just pull it out - and push in the new one......after taking off the 'choke' links of course.

[mike.perry]

If you replace the jet on an H1 or 2 then you will need to fit a jet sealing kit as the original cork seals will have been disturbed and are likely to leak. I would also recommend buying a copy of SU Reference Catalogue from Burlen Fuel Systems which gives precise instructions.
The HS2 was a later fitment to the 948 Minor

[Morrisminormo]

Hope this picture uploads, this is what's in the kit,

Part of me is thinking leave it alone and buy factory new h2 carb for £200

If I buy kit and mess I have 3 days to fix my car, otherwise ill have no trsnsport [frame][/frame]

[bmcecosse]

DO NOTHING! Just run the car - there's nothing seriously wrong with a car that can do 50 mpg....and 30 mpg is a very realistic running average for a commute. DO NOT buy a new H2 carb.....