Topic: testing continuity of ignition coils

[jason41987]

hey.. i have a honda service manual with me.. but some of the terminology isnt too clear.. tells me to check the continuity of the wires on the outside of the body of the ignition coil.. i get continuity.. but then it appears to be telling me to stick the probes of my multimeter into the ends of the large cables that plug onto the spark plugs.. and with a probe in each of these wires i should get continuity? if so, i do not get continuity

[steam-powered man]

at the top of this page, click on "single overhead cam 4 forums", click on 'FAQ", click on "ignition, coils and pluds", then read the post by steved. 

i recently used this faq to diagnose a "no spark" problem i had.

found a combination of bad/poor caps, coils were fine. 

remove the plug caps on the coil, you should have continuity between the spark plug leads.  (this eliminates the faulty cap question).  if no continuity, try cutting the leads back 1/4inch and try again. 

[jason41987]

i followed that.. and thats whats confusing.. the honda manual says to check for continuity.. my multimeter doesnt find one, no beep.. however when i switch to 20k ohms, i get about 15 on one coil, and about a 16.8 on the other

[jason41987]

i just noticed i get no continuity, nor do i get any resistance readings when i test the plug caps themselves... i tested all of them with the same results, what are the chances all spark plug caps would be bad?

---

aah.. got a reading on one of the plug caps... about .4 on the 20m ohm setting

[HondaMan]

i followed that.. and thats whats confusing.. the honda manual says to check for continuity.. my multimeter doesnt find one, no beep.. however when i switch to 20k ohms, i get about 15 on one coil, and about a 16.8 on the other

That shows 15k ohms on one coil, 16.8k ohms on the other. Reasonable numbers for the high-tension side.

[HondaMan]

i just noticed i get no continuity, nor do i get any resistance readings when i test the plug caps themselves... i tested all of them with the same results, what are the chances all spark plug caps would be bad?

---

aah.. got a reading on one of the plug caps... about .4 on the 20m ohm setting

These give up after either about 5-8 years, or 10k miles. Use the 5k (5000) ohm variety today, with stock coils. They are about $5 each at you local bike shop. Bring your old ones along, as there are 12 different shapes and sizes (and also 0 ohm, 5k ohm, and 10k ohm varieties), so match up your cap body size, holes in the rubber boots, and make sure of the 5k ohms value.

[jason41987]

so then, in all likeliness, this bike which has been spending many, many years just sitting... the plugs have all gone bad due to the age?... and i dont have a "bike shop" where im at... would autozone have something sufficient?

[bollingball]

Auto Zone can order the NGK caps. But you will have to tell them exacly what you want. They don;t know squat Or you can order them here.
http://www.z1enterprises.com/ListItems.aspx?keywords=ngk+caps
Ken

[jason41987]

any idea what size i need for the caps?

[jason41987]

im also curious as to what other spark plugs are compatible with this engine?... i may replace the plugs too

[fmctm1sw]

im also curious as to what other spark plugs are compatible with this engine?... i may replace the plugs too

D8EA or X24ES to name a couple.

[jason41987]

well, seems the spark plugs are good.. brand new actually, must have been changed in the last owners desperate attempt to get spark.. points and condensers are new as well, coils are good.. i guess he got stumped on the plug caps.. so im ordering those.. also took off the carburator to disassemble and rebuild.. then there should be no reason this thing shouldnt fire right up

[jason41987]

with the NGK spark plug caps listed on a link in an earlier post on this thread... which ones actually work with the CB550?.. the right angles i dont think will clear the cylinder heads.... so that leaves 120 degree, 102 degree, and straight... has anyone used any of these caps? if so, which ones?

[bollingball]

with the NGK spark plug caps listed on a link in an earlier post on this thread... which ones actually work with the CB550?.. the right angles i dont think will clear the cylinder heads.... so that leaves 120 degree, 102 degree, and straight... has anyone used any of these caps? if so, which ones?

Maybe TT or Dave500 or another 550 guy will see this I have a 750K and don't know how different the heads are. On my 78 2&3 use the straight 1&4 get the 120. What year is your 550? K or F?
Ken

[Chachi]

This is what I did recently with my 72 500...

"I re-did my plug wires with the NGK splice connectors, new wire and new resistor caps. I went with the XD05F and VD05F caps."

Thread about it here; discusses NGK plug cap options with comments/info:
http://forums.sohc4.net/index.php?topic=105814.0

[Chachi]

If you don't have a local shop... I had good luck ordering everything I needed from denniskirk.com. I have local shops, but none of them carried the NGK caps that I needed. Some auto parts stores could probably order them too; Napa tends to be the best for that around me.

[bollingball]

I'm thinking 1-4 XD05F 2-3 SD05F Most of the old timers prefer the Denso that is the X24ES-U plugs. But wait for confirmation.
Ken

[bollingball]

Sorry Chachi posted while I was having a brain fart.
Ken

[dave500]

ive used both the ngk and the denso u gap for miles and miles in 500/550s,id call them equal,,just dont use champion,ill buy either denso or ngk only.

[jason41987]

well i have one vote for the XD05F for the outside cylinders and SD05F for the inside cylinders... can anyone else confirm these will work well and fit properly?.. the bike is a '76 550F

[lucky]

hey.. i have a honda service manual with me.. but some of the terminology isnt too clear.. tells me to check the continuity of the wires on the outside of the body of the ignition coil.. i get continuity.. but then it appears to be telling me to stick the probes of my multimeter into the ends of the large cables that plug onto the spark plugs.. and with a probe in each of these wires i should get continuity? if so, i do not get continuity

Continuity is when you have a wire, and you put a probe on each end from your test meter on the OHMS scale.
The meter will read ZERO of you have continuity, meaning a good connection. No breaks in the wire. If the meter reads INFINITY   (figure 8 laying on its side) it means there is no connection and the resistance is infinite. No connection -a break in the wire.

This is a very important concept!!!!!

[jason41987]

can anyone else confirm that 2x XD05F and 2x SD05F are the right plug caps for the cb550f?

[dave500]

i use four of the xdo5f,,the angled ones,if your leads havent been snipped back a few times and are much shorter the ones you mentioned will be fine,youll have two angled and two straight ones.

[jason41987]

both of these coils seem to have the length of wire for the 2 and 3 cylinder spark plugs.. im not sure if theyll reach the outside plugs well enough or not... still the two straight and two angled though?.. or are four angled going to be better?

[dave500]

i like the four angled because any water wont go down the straight ones,the original set up was two of each and its fine.