23 replies to this topic

[kells65row]

City 1000 (was running fine) now fitted with a 1275 (will not fire)
City is 1986 - the 1275 is out of a 1979 1275GT (Pedigree unknown)

Prior to dropping in the 1275 - I did check the bore to make sure the 1275 was standard - it appears so, new head gasket, valves were seating fine so left alone, torqued down and re-set roacker to valve clearance 12 thou.
Starter motor transfered from 1000.
Heated inlet (left cold) with HS4, K&N and new needle.
New LCB straight link to single box RC40.

Have substituted the following from the 1000 just to try to get things going -
HS4
Dizzy cap + leads
Coil + lead
Points and condenser.

There is a spark at all four plug leads.

Timing - Static, set the points to just opening (using a lamp between the coil -ve and earth i.e lamp just coming on) at both 13 BTDC and about 8 BTDC i.e flywheel numbers ahead of 0 (on the left).
There is fuel in the carb reservoir.

All suggestions welcome.
Cheers

[dklawson]

Since the engine is unknown to you, even though you have set the static timing, check the distributor again. With the valve cover off, turn the engine over until piston #1 (radiator end) is near the top. Its rocker arms should be loose at that point (so you can wiggle them, indicating the valves are closed). If the arms are "tight" turn the engine over one more full turn until #1 piston is at the top again and its rocker arms are loose. Now remove the dizzy cap and note where the rotor is pointing. Make sure the plug wire the rotor would be aimed at is connected to spark plug you place in cylinder #1. Now make sure the other wires are positioned correctly counterclockwise around the cap, 1-3-4-2.

Following the engine swap you will have had to re-connect the manifolds. Make sure they are seated firmly against the head and that all the fasteners are tight. Look carefully at your intake manifold. If there is a brake servo connection to the manifold, make sure the hose is connected. Make sure your choke mechanism is working also.

If the engine still fails to start after checking all these things, tip a thimble of gasoline down the carb throat and try again. If the engine fires, then quickly dies, you know that the problem is not in the ignition system but in the fuel system.

[stocky]

How well does it turn over?, could be flat battery, timing or fueling,

If you have sparks then id say timings out or the new needle has trown your mixture out, mine ran ever so badly when I put a stage one on it, was running super rich,

Ive even got the leads 180 degrees out before now so check that as well

[Pitcrew6464]

can you take a photo it will be easyer to diagnose for you

[tom-gary]

was the 125gt running befor you put it in ?
possiblet compresstion if uv had the head off

[Pauly]

Also make sure the manifold flanges are level so the nuts tighten both manifolds up evenly, otherwise you will be suffering air leaks.

Edited by Pauly, 21 April 2010 - 07:42 PM.

[kells65row]

Since the engine is unknown to you, even though you have set the static timing, check the distributor again. With the valve cover off, turn the engine over until piston #1 (radiator end) is near the top. Its rocker arms should be loose at that point (so you can wiggle them, indicating the valves are closed). If the arms are "tight" turn the engine over one more full turn until #1 piston is at the top again and its rocker arms are loose. Now remove the dizzy cap and note where the rotor is pointing. Make sure the plug wire the rotor would be aimed at is connected to spark plug you place in cylinder #1. Now make sure the other wires are positioned correctly counterclockwise around the cap, 1-3-4-2.

Following the engine swap you will have had to re-connect the manifolds. Make sure they are seated firmly against the head and that all the fasteners are tight. Look carefully at your intake manifold. If there is a brake servo connection to the manifold, make sure the hose is connected. Make sure your choke mechanism is working also.

If the engine still fails to start after checking all these things, tip a thimble of gasoline down the carb throat and try again. If the engine fires, then quickly dies, you know that the problem is not in the ignition system but in the fuel system.

Thank you for the advice - have checked that the #1 is on the compression stroke and the dizzy is pointing to no 1 lead. 3-4 and 2 follow counter clockwise. The distributor cap I transferred from the 1000cc which I had labelled up 1 through 4 as well just so I did not get them wrong. The dizzy cap leads, points and condenser were all working on the 1000cc before the engine was removed.
The manifolds look all correct and tight and I don't have a brake servo. The Carb currently on the 1275 is a known working item again from the 1000cc but with a new needle. It appears to be functioning correctly both externally and when looking inside with the carb piston removed.
Off to find a thimble !!

[kells65row]

was the 125gt running befor you put it in ?
possiblet compresstion if uv had the head off

The 1275GT has not been running under my ownership.
That is one thing I don't have is a compression tester. May be worth asking around though.
Thank you for that.

[bmcecosse]

You SURE the valve gaps have been set correctly? Is there obvious compression on the engine ? Just spray carb cleaner into the inlet, or tip in a splash of petrol - if the ignition is right it will fire up. If not - recheck the ignition!

[kells65row]

can you take a photo it will be easyer to diagnose for you

Let me know if I there are specific areas.

Attached Files

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[classic mini]

City 1000 (was running fine) now fitted with a 1275 (will not fire)
City is 1986 - the 1275 is out of a 1979 1275GT (Pedigree unknown)

Prior to dropping in the 1275 - I did check the bore to make sure the 1275 was standard - it appears so, new head gasket, valves were seating fine so left alone, torqued down and re-set roacker to valve clearance 12 thou.
Starter motor transfered from 1000.
Heated inlet (left cold) with HS4, K&N and new needle.
New LCB straight link to single box RC40.

Have substituted the following from the 1000 just to try to get things going -
HS4
Dizzy cap + leads
Coil + lead
Points and condenser.

There is a spark at all four plug leads.

Timing - Static, set the points to just opening (using a lamp between the coil -ve and earth i.e lamp just coming on) at both 13 BTDC and about 8 BTDC i.e flywheel numbers ahead of 0 (on the left).
There is fuel in the carb reservoir.

All suggestions welcome.
Cheers

try spraying easy start into the carb if it starts you then know that it is a fuel problem

[kells65row]

How well does it turn over?, could be flat battery, timing or fueling,

If you have sparks then id say timings out or the new needle has trown your mixture out, mine ran ever so badly when I put a stage one on it, was running super rich,

Ive even got the leads 180 degrees out before now so check that as well

Turns over fine - as far as I can tell. I have put two batteries in parallel just to make sure it was not a current (I) problem.
Will try the old needle back in tomorrow.
On timing - have even used a bulb across the points so to be accurate when setting the timing (static obviously).
Any idea what the static timing should be on a 1275 (1979) with a dizzy 41768. My static chart only goes up to 1976. I had assumed 8 degrees?
Thank you for the suggestions.

[kells65row]

Also make sure the manifold flanges are level so the nuts tighten both manifolds up evenly, otherwise you will be suffering air leaks.

OK will do.
Cheers

[blacktulip]

where are you based?

[mk3 Cooper S]

Is the dizzy set up correctly? 180 deg out?