CX500 GL500 650 Global

the resistors might well be a eu / au /us restriction to meet RFI.
The comment re interference is probably not relevant to CDI bikes as the input voltage is large for the triggers - but might be relevant with the TAI ones,
and is certainly known to have caused issue with first generation EFI systems on bikes and cars.

Not saying it is or isnt significant - BUT - the resistor does slow the front edge of the spark - which also has some impact on the coils and
the output capacitor of the CDI unit itself -

All i;m suggesting is that the highly conservative amongst us might like to use resistive plugs if swapping out the resistors in the plug caps as this will keep the system the same overall.

Rayman

Rayman wrote:the resistors might well be a eu / au /us restriction to meet RFI.
The comment re interference is probably not relevant to CDI bikes as the input voltage is large for the triggers - but might be relevant with the TAI ones,
and is certainly known to have caused issue with first generation EFI systems on bikes and cars.

Not saying it is or isnt significant - BUT - the resistor does slow the front edge of the spark - which also has some impact on the coils and
the output capacitor of the CDI unit itself -

All i;m suggesting is that the highly conservative amongst us might like to use resistive plugs if swapping out the resistors in the plug caps as this will keep the system the same overall.

Rayman

Fair point Rayman.I understand

The resistor was very very badly corroded as can be seen. It looks in worse condition than that of the original in this post. I was surprised that everything came out with minimal effort. I hope the left side is as easy.

10 MINUTES LATER: HOLY SHIT!!!!!!!!!!!!!!!!!!!!
I disassembled it and put the original corroded stuff back in and used my motion pro ignition tester set at 6mm and cranked it: ah, a bluish spark nothing to write home about. Then I installed the brass rod and re-tested.

It looked like a FAT BLUE lightening bolt inside that tester! Really Impressive.

I just removed the left side and it looked just fine. the resistor was intact and not dead. But I am going to replace that assembly with a brass rod anyway!

10 minutes after that: I am not gonna sell the farm and start lighting candles and all but, and i might just be delirious from gas fumes but i did see an improvement in throttle response. Too bad the roads are too wet right now to go out and open her up a bit, but i am nervously optimistic.

Finger crossed

Hi,
Here in South Africa there are very few good CXs running aroud as the were not very popular. I have a 1980 model and after checking voltages on both blue and white wires and reducing spark plug gaps the misfire was still there until I read your article. The old girl can now red line again without any effort.
Great Article.
Regards,
Rohan Els.

Rohan wrote:Hi,
Here in South Africa there are very few good CXs running aroud as the were not very popular. I have a 1980 model and after checking voltages on both blue and white wires and reducing spark plug gaps the misfire was still there until I read your article. The old girl can now red line again without any effort.
Great Article.
Regards,
Rohan Els.

Cool.It's great to keep another one running.There is a bloke I'm pals with over there who runs a CX650.I'll see if he will jon the forum and you may be able to meet up

However if you are stuck for parts just let me know as I have quite a few decent 2nd hand parts.Remember pre-emptive oil changes for the engine and drive box,tappet setting,coolant change and cam chain adjustments go a long way to keep these bikes running for well over 150,000 miles without many problems(Change cam chain if you ever hear an engine knock other than a clutch rattle or other identifiable sound).

call me crazy and let me know if this is a stupid question. Brand new NGK hard plastic spark plug caps at your honda dealer, $3.87 ea. why go through all this when an easier solution is not that costly. Unless I'm missing something.

If they are the right type then that's a great price.The plug caps on these bikes are little special in length and angle required to use the plug cap Rain boots.

I am having problems with my engine not going past 5000 rpms without it bogging down. I saw this article and pulled the caps off to look for corrosion. What I found was some black charring on the right side cap rod and aluminum rod but there was no spring in there just the aluminum rod and the resistor. On the left side I found an extremely long spring the resitor and no rod. What gives? I put a drill bit down the tube to measure how far back it would go and can see from the measurment it reaches all the way to the back. Could someone have taken this apart and not reassembled correctly or is this the way it came from the factory? If it is factory wiil a new brass rod, (your method) still do the job?

Please put your location in your signature or under you Avatar as it helps me pinpoint my replies for parts.


The resistor type ones have a spring spring,rod and resistor.If those the three components are not there then either they have decayed or as you say I think some one has messed with it.


It seems there's no supplier for the Plug caps in the US but I know a fair few people in the US who have bought from the excellent Wemoto in the UK(Where I get mine) as they are a good company and ship internationally.

http://shop.wemoto.com/index.dyn?oid=1911758

The ones from this page are the better,simpler none resistor type ones and will work on all models.As they will most likely last another 30 years I think they are a worthwhile purchase.If this doesn't cure the rev problem at least you will know you have eliminated them as a fault cause.