25 replies to this topic

[classicoop]

How revvy is a 1275 cooper Hif44 (BFY needle, around 6deg timing with vac pulled)?

 

It free revs past 4k, but in gear even 1st, it's like hitting a brick wall.

 

Pulls great til around 4-4.5k.

 

What should I look at? Mixture?

[smartie93]

6 degrees BTDC? sounds a bit too retarded to me, your mixture isn't given enough time to burn at higher rpm reducing power. try slightly advancing the ignition, just keep advancing to the point where it will drive under load without pinking :)

Edited by smartie93, 13 May 2013 - 02:26 PM.

[classicoop]

Forgot to mention this is with electronic ignition (if that makes a diff).

 

It was set based on Haynes specs for = 5+1 @ 1500rpm.

 

How much timing do you guys usually run or just run til it pinks? I just find it odd that stock timing won't rev past 4k

 

-----------it will rev past 4k but not with the same "oomph"------------

[iwatkins]

Done the usual checks like making sure enough fuel is getting through? Revving while standing still isn't going to use the same amount while under load.

 

Checked that the throttle cable is fully opening the throttle at the carb end (I'm assuming carb as you said it has elecy ignition). I had a slipped cable and found it was OK to about 4.5k in any gear but then took forever to rev past that.

[smartie93]

Forgot to mention this is with electronic ignition (if that makes a diff).

 

It was set based on Haynes specs for = 5+1 @ 1500rpm.

 

How much timing do you guys usually run or just run til it pinks? I just find it odd that stock timing won't rev past 4k

 

-----------it will rev past 4k but not with the same "oomph"------------

I assumed it was leccy igntion :) 

 

Is that the standard for your particular engine spec or the A series in general? 

 

Ignition timing varies with engine spec; cam characteristics, compression etc Unless you have rebuilt your engine you have no way of knowing for sure what's inside it. Compression will also drop with age

 

Adjusting the ignition is an easy job to do and requires no real dis-assembly so I would just check it first, and if it solves the problem, it's one less thing to worry about :)

 

Though a Rolling road would be the best place to go to set it up correctly

[classicoop]

Cable opens throttle 100%.

 

Fuel starvation, how to check? I was thinking this also, because I was hearing something that sounded like pinking, but dismissed it as metal vibrating to engine frequency at around 4-5k.

[jaydee]

Dont know what ignition curve you're running, but you need a static timing of about 12 deg with the 1275

[elanbaby]

How revvy is a 1275 cooper Hif44 (BFY needle, around 6deg timing with vac pulled)?

 

It free revs past 4k, but in gear even 1st, it's like hitting a brick wall.

 

Pulls great til around 4-4.5k.

 

What should I look at? Mixture?

 

 

-Perhaps the centrifugal advance has rusted solid?  Mark the pulley at 28 deg BTDC, rev the engine up to 5000rpm and check with a strobe that the timing advances porperly.

 

-Mixture? Have a look at the plugs.

 

-Fuel starvation? Any filters clogged? Tank building up vacuum?

 

-excessively worn cam?

 

-air filter dirty?

 

Thers´s plenty to check really and it could be all or something else...

 

Juergen

 

Edited by elanbaby, 13 May 2013 - 03:08 PM.

[classicoop]

Elanbaby thanks for the tips.

 

Didn't think about cam wear or dizzy getting rusted out.

[elanbaby]

When my engine didn´t rev freely IT WAS a rusty pair of advance weights. I probably have the same electronic dizzy as yours (65DM4)? The cap is held down by 2 screws rather than spring clips. As there are no points inside, people often "forget" that even tihis dizzy is mechanical and benefits from a drop of oil at the spindle and the advance mechanism from time to time. Worth checking. 

 

Juergen

[cal844]

my 65DM4 is constantly oiled haha, it leaks at the module on the side 

[Dev20]

How do you get to the advance mechanism of the 65Dm4?

[classicoop]

How do you get to the advance mechanism of the 65Dm4?

 

+1? Do I just Wd40 the spindles and hope for the best?

[classicoop]

I think I just figured it out (looking at pictures).

 

Remove cap > remove arm > remove bolts holding the distributor together

 

I assume this can be done in-car right?

[elanbaby]

Although it´s only three weeks since I dismantled my 65DM4 I forgot how I did it   I DO remember that ít was dead easy but I removed it from the engine and did it on the bench. Anyway, I dismantled it after I checked the ignition advance with a strobe and realized there wasn´t much.

 

If the advance works properly leave it in and just put a drop of oil at the spindle and squirt some WD40 at the advance mech. 

 

Juergen

Edited by elanbaby, 14 May 2013 - 06:22 AM.