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Running on only two cylinders

Posted: Fri Jan 27, 2006 7:12 pm
by 2-DOOR
Hi everyone, i really need your help. I have just bought another minor (non runner), and i have just fitted the following:new points, plugs, leads, condenser, dizzy cap , rotar arm and coil, i eventually got her started, but alas shes only running on number one and number three cylinders , with no spark at all going to cylinders numbers two and four. Has anyone any suggestions as to what is going on? All suggestions will be very gratefully received. Thank you in anticipation. Sam.

Posted: Fri Jan 27, 2006 7:18 pm
by Onne
Have you tried another dizzy cap? There were some faulty ones a while back

Posted: Fri Jan 27, 2006 7:45 pm
by 2-DOOR
Hi Onne, yes i have, three actually, with no results i'm afraid, sorry forget to mention, when i take the dizzy caps off, there are metal filling inside them, and ther are big tracks cut into the four metal inserts inside the cap, could the dizzy drive shaft be bent?, would this cause her to run on two cylinders?Many thanks. Sam.

two cylinders

Posted: Fri Jan 27, 2006 7:54 pm
by Willie
Well, logic says that if two of the cylinders are receiving a spark that rules
out the points, condensor, and rotor arm. You are left with a faulty dizzy cap,
faulty spark plugs, and faulty HT leads to numbers 2 and 4. A remote poss-
ibility is that chronic wear on the dizzy cam lobes means that the points are
not opening on 2 and 4 but that is easy to observe. You could also look at
the electrodes in the dizzy cap which pick up the voltage from the rotor arm.
These can build up a very thick greyish layer which chips off very easily if you scrape it with a knife or similar. I assume that you have swopped over
the working plugs with the non firing ones to eliminate faulty plugs? If no joy
then swop over one of the working plug leads with a non working one. If still
no joy are you sure that it is faulty ignition and not lack of compression etc??

non firing

Posted: Fri Jan 27, 2006 8:00 pm
by Willie
Oh, just seen your additional post! If the dizzy spindle is running true (turn
the engine on the starter and observe) then you had better compare the new
rotor arm with the old one as it looks as though it is physically too big!! I have
only once seen metal filings like yours and that was because only one of the
spring clips which hold the dizzy cap on was fixed which allowed the cap to
tilt when the engine was running.

Posted: Fri Jan 27, 2006 8:09 pm
by bmcecosse
Are you sure the spark leads are in the correct order - 1342 - with the rotor arm running anti-clockwise. It would be easy to have 4 and 2 swapped round in the wrong order! You say 'no spark' - but have you actually tested for a spark on these leads ? It could be a very badly worn (or bent) dizzy - can only suggest waggling the spindle to check for wear - and measure the points gap on each lobe in turn to check for bent shaft. The rotor arm could be too long I suppose - you would need to measure it and compare with the diameter across the cap between the contacts.

Posted: Fri Jan 27, 2006 8:15 pm
by 2-DOOR
Hi Willie, i have checked all the spark plugs, they are all ok, i have chaned the leads for ones that i know are ok, and the rotar arm is the correct one, but still no spark to cylinders 2 and 3.

Posted: Fri Jan 27, 2006 8:20 pm
by bmcecosse
Hang on - you said 2 and 4 before, now it's 2 and 3 ! I ask again - is there really no spark - or are these two cylinders (2 and 3) just not firing ? If so - it's almost certainly blown head gasket between the two. Turn the engine over with the handle - and feel if there is even compression on all 4 cylinders.

Posted: Fri Jan 27, 2006 8:21 pm
by 2-DOOR
Hi bmcecosse, yeah running 1342, i have checked for spark by taking one lead at a time of, when i take numbers 1 and 3 off, i can hear the spark cracking, and see it also, the same does not happen when i repeat this process with numbers 2 and 4.

Posted: Fri Jan 27, 2006 8:26 pm
by 2-DOOR
sorry bmceosse, typing error, the problem is with numbers 2 and 4.

Posted: Fri Jan 27, 2006 8:27 pm
by bmcecosse
Is it 2 and 3, or 2 and 4 which are not sparking ?

no spark

Posted: Fri Jan 27, 2006 8:27 pm
by Willie
Well, if you are sure that the rotor arm is the correct one there can only
be a bent spindle if you are getting metal filings!!

Posted: Fri Jan 27, 2006 8:29 pm
by bmcecosse
Aye - it sounds like it - check the points gap on each lobe in turn. Since 2 and 4 are together - it does rather look like a bent spindle.

Posted: Fri Jan 27, 2006 8:29 pm
by 2-DOOR
2 and 4 are not sparking.

Posted: Fri Jan 27, 2006 8:32 pm
by 2-DOOR
Thanks for all your help guys, i will change the dizzy tomorrow, and let you know how i get on. Sam.

dizzy

Posted: Fri Jan 27, 2006 8:41 pm
by Willie
SAM, that would be nice! Most of the time we don't get feedback.

Posted: Fri Jan 27, 2006 10:46 pm
by minor_hickup
i had a similar problem, have you tried a new set of HT leads?

Posted: Sat Jan 28, 2006 4:40 pm
by bmcecosse
I think he has swapped them around without any change. We are all waiting to hear today's progress!

Posted: Sat Jan 28, 2006 8:38 pm
by 2-DOOR
Hi all, well i'm just back from my shed (its 20miles away) and its.........GOOD news, she's now running on all four cylinders. it turns out the dizzy spindle was bent , as soon as i put another dizzy in, she started up on all four straight away. I would like to thank you one and all who offered advice as to what the problem might be. Sam.

on 2

Posted: Sat Jan 28, 2006 10:52 pm
by Willie
excellent....enjoy.