mk1-forum.net

I'm trying to help a friend to re-gain some motivation to finish his car. It's a 998 MK2 mini which is in the same state (shell painted, mechanics fitted) since 2008 or so. No evolution since then.

So, a couple of months ago I went to his house to try to fire her up, first start after rebuild. The engine was rebuilt by a known portuguese builder who wins races and knows his stuff. This to me, at this point, doesn't have much significance since mine was at first also built by someone reputedly good and was destroyed after 500 metres running due to several parts missing inside it Sorry, kind of lost my faith. BUT, I have to give some credit because although I saw things I didn't like, I'm really trying to assume the basics are right. They have to be. C'mon... his job is rebuilding engines everyday.

The first thing I did was trying to rotate it. For starters, it was stuck. With one wheel in the air, both of us eventually got it loose. It only had a bit of oil (assembly oil?) which we took off and replaced with new oil.

Then rechecked the cylinder head torque (40lbft)... half of the nuts were loose. Rocker gear (new 1.5 rockers) had these tiny spacers (half the size they should be) which were doing nothing, completely loose. I had to get the springs from the old set. Valve clearances were also wrong.

Next... dizzy advance totally stuck. We refurbished the dizzy (oh... and the starter) and I put the dizzy with a static advance of 7/8º BTDC. Then the solenoid didn't work (new Lucas one), the old one did. We got good oil pressure but the engine felt slow rotating, like everything was tight. Mine is a 1275 with tight tolerances and spins much, much freely. The battery was fully charged and when that died we went to get another, more powerful, from a diesel car which gave the same intensity spinning the engine. It really feels tight, also by hand, but is constantly tight. No grabbing spots. At the speed the starter rotates it, it should present no problem to start.

Fuel: the carbs were refurbished by me and I know they're good. No air leaks in the manifolds. Plugs with fuel after a few times rotating the motor, so there's definetely fuel coming into the chambers. Cleaned spark plugs several times.

Spark: I'm 100% sure that when the firing stroke was occurring in each cylinder, the dizzy rotor/lead was pointing at that cylinder. Checked and rechecked that several times. All 4 plugs had sparks, they're not very strong but they're not weak either. 2 coils tried, 2 sets of points, 2 condensers, 2 dizzy caps + leads, sparks are new BP6ES gapped at 0.8mm. 2 earth straps well fitted. The strenght of the spark was always the same.

Compression: after a bit insisting to fire up, it eventually back fires through the exhaust, so there's compression accumulating. I'm assuming the pistons have rings

After this, it was late and I had to return (150km each way), but promised to return again some day to fire her up. I should go there next week or so. Since it's a long distance, I want to go with a plan to at least diagnose the problem. I'd like to give him (and know myself) some answers.

I need to check if the timing gears aren't 1 tooth off. How can I do that without taking anything appart? If we split the overlap (rockers rocking) on the 1st cylinder, the flywheel should present exactly the TDC mark, right? If the timing was 1 tooth off, should I have noticed it was not right when setting the ignition (how much impact 1 tooth off has)? Do you have any other ideas for me to check out? Any thoughts?

- We have oil pressure
- We have petrol
- We have spark
- We have compression
- Ignition timing seems OK
- Does not fire up, never even once gave a heart beat

The engine build doesn't sound too good. None the less, check all the valves are opening and in particular, closing, ie, that none are getting stuck, this can be one reason for back-firing out the exhaust.

If all that is OK, then the ignition timing sounds like it's out, probably by 180 degrees.

Some of the items you've so far found and listed is not good considering someone has paid good money to have all this done. Hard to say, but if it were me, I'd very seriously contemplate pulling the engine down rather than running it and possibly doing expensive damage. The items found thus far are pretty basic things and it makes one wonder how much attention, to the detailed things, has been paid.

I agree with Spider.

A couple of things though:
1. Spark plug gaps should be 0.6mm

2. When I re-built my first Mini (at the tender age of 16), I had real problems to start it. I tried every evening for 2 weeks!! -Even removing the radiator to re-check the cam timing...
Eventually I asked a colleague if he could help (I was on the point of pouring petrol over the car and cremating it!! -I had fully re-built everything on the whole car!!)

Anyway, he looked at the car, checked a few things, then asked if I had tried "hot-plugging" it. What?
-Basically, remove the spark plugs, heat them up (I used the gas cooker in the kitchen!), then stick 'em back in quick and try and start it.

It fired-up immediately
-His theory was that, as everything was new, there was no "petrol-memory" on anything.
Don't know about the science, but it always started without any problem after that!

-Now when I build a new engine, if it doesn't start after a few tries, it's out with the plugs and blow-torch.
Works every time for me

Might be worth a try?

/Andrew

It does sound like you could have some issues.

The best thing to do is check things systematically, try not to go off at a tangent thinking it could be this it could be that.

Personally I always check everything about the distributor first, spark, timing, advance, leads, plugs etc. If & only if all that is working OK will I move onto the fuel system, pump, lines, carbs etc. If after all that I can smell pertol & have a spark, it's time to get dirty & do the rockers & check the valve timing. Usually mystery non starts like this are due to the dizzy being timed in wrong, either 180°'s out or just somewhere wrong. But as I say work through it systematically and check everything in order.

I bet it starts after that.

M

PS. If it has been stood for that long, remember to prime the oil pump!

Thanks for all replies.

@Spider: rocker cover off, all valves open and close, no valves stuck. I checked from the dizzy spindle to the leads and plugs. All is where it should be. By the end of the day, more tired than thinking, I gave it a go 180 out (swapped the leads) and it backfired through the carbs which means it was right at first.

@Andy: hot-plugging - we'll try that, thanks.

@Mark: I did go through it systematically: we started by having oil pressure (pump primed), then we refurbished the dizzy (advance was stuck), set it at 7/8º static BTDC and set the points gap. Checked for spark and it was there in all 4 of them. We used a 12V bulb we had at hand connected from the coil to the dizzy and rotated the engine by hand to make sure it was firing where it should be (all good, ie, firing on all compression strokes and correct cylinders). Only then we added the fuel and tried to fire it up. The fuel smells after a while and is visible if we pull the plugs.

Maybe it's just a matter of persistence (and hot plugging)? We did spend all day solving other problems before getting to it. Shame he lives far away and goes abroad very often.

Great! That's it

My dad used to call that "engine rebuild in a can"
Because, if the engine backfired, there was a good chance it was going to get damaged.

Brake cleaner works OK too, funny I seem to use it for everything and when I come to do brakes have none in stock!

when I come to do brakes have none in stock!

I know that feeling

M

Don't use Easy Start ,That kills engines!! If it needs that stuff then there is something wrong !!!!

Are you using old stale petrol ????????? For some reason old stale petrol becomes useless, My motor bike would not start after being stood 3 years , wet plugs ,I drain the petrol, put new fresh petrol in the tank , dried out the plugs and away it went

Goff

Try this!

If we split the overlap (rockers rocking) on the 1st cylinder, the flywheel should present exactly the TDC mark, right?

Correct if you have TDC, valves on the rock on cylinder four, your rotor arm should be pointing to number 1 lead, from there you could adjust your timing on the distributor, this will get you very close, close enough to eliminate timing problems anyway.

Have you tried a tow start often good for stubborn old car's that refuse to start.

Just as a matter of interest, why do you think that a whiff of ether / easistart would "kill an engine".

M

easystart is sh!!e
if you have to start an engine on that muck you have a problem
as Mark says check ignition timing,points,condenser,coil,spark etc etc do the basics first.
easystart is ok if the fuel is knackered and car has been stood for donkeys and thats it.

Point 1) I never mentioned easy start, fortunatelly we don't have it here as far as I know and I don't care about it. The engine has to start the way it should.

Point 2) Please read what I wrote. There is a reason why I wrote a big post in the beginning explaining everything I've done... and another one after that complementing it. I know it takes a little effort to read such a long text, but I wouldn't expect proper help if I didn't give as much details as I could. The basics were done and it didn't start... yet. I (maybe) will go there next week, then I'll have more information. For now, the basics were done and didn't work, it's all I know.

I don't want to sound rude, but that start with the basics advice sounds like maybe you didn't read what I described in my previous posts. Please read it and if anything comes to mind, please post.

Hi Ricardo

I had a similar phenomen last year with a Riley mk2.

after checking and chanching carbs, coils, dizzis, plugs and so on i nearly lost my courrage!

i then remarked only by hazard that the dynamo is making strange sparks inside the dyno housing.

i changed the Dynamo and the Engine immediatly started.

to this day i can not explain why, but it sems that in my cas the dyno was the reason...

may it helps you?

best regards

just some thoughts..

check cam timing and do compression test
fresh petrol
new plugs .
new condenser.
2nd battery connected to coil and block earth only .
crank on first battery and use 2nd for coil . if it starts pull off 2nd battery leads to stop it running .
investigate original 12v supply to coil.
if using a dvm to measure your coil supply,it can read 12v , but the car does not supply the amps needed because of breakdown somewhere in the 12v feed .

good luck with it ,
robert

Perhaps there's too much fuel coming into the chambers. Is the fuel float good? Even though they were rebuilt it could have a hole in it. When you rebuilt them did you check the needle for either wear or if it was the correct size? Did you do a suction test on the plunger to make sure it wasn't falling too fast or sticking in the chamber? Unlikely but could cause the engine to flood, especially with the choke all the way out.

Rebuilding carburettors doesn't guarantee they're good. Especially if your yard stick is a badly rebuilt engine that hasn't run before. A carburettor is just that, a metering device. Wet spark plugs doesn't equate to metered fuel mixtures.

Pulled the timing cover to check the sprocket alignment?