hot cdi units

[Jockney Rebel]

the 2 seperate OKI cdi units on my bike get so hot they melt the black sticky shit in them i took the bike to a shop up here that deals with older stuff and he told me that its a common occurance on these old hondas and said dont worry .....
is there anything i can do about it as i dont want one of these buggers shitting itself on a long haul
ta

Old honda recos` run REALLY HOT all the time replace it with one from a yamaha(seriuos):D

[Jockney Rebel]

cheers mad
ur up round here somewhere aint ya ?or were u just visitin ?

Was up visit`n:Dbut also looking at RE.

[shift1313]

that black stuff is potting compound. It usually melts between 120-200F 45-98C. I cant imagine they run hot enough to melt that stuff. If that happened on my bike i wouldnt just let it go. Its probably a bad component inside. Can you open one up without too much trouble?

[loosebruce]

http://www.vlc.com.au/~justin/about/bikes/honda/reg_replace.html
Was looking at this the other day, took a while to find again

[Jockney Rebel]

quote:Originally posted by shift1313

that black stuff is potting compound. It usually melts between 120-200F 45-98C. I cant imagine they run hot enough to melt that stuff. If that happened on my bike i wouldnt just let it go. Its probably a bad component inside. Can you open one up without too much trouble?
they ve got one side open anyway they sit on the frame back to back just under the seat forward of the tank..everyone ive looked at is the same ..bout 4 bikes so far all with the same problem
my local breaker[wrecker] has 10 sets of them and theyre all showin signs of meltin too
but if i can wire another more reliable cdi unit then i will ..got more important stuff now i just stripped the fuel tank back for sprayin and its full of filler and has a big braze right across the r/h side :(

[Jockney Rebel]

http://www.streetfighters.com.au/forum/upload/768620561219118.jpg
thanks for all ur advice but i think theres a bit of confusion going on the rec/reg is ok its these little bastrds that are gettin hot i know them as cdi units capacitor discharge ignition units they might also be known as trigger units.you can see them in the pic just to the right of the battery the rec/reg lives on the side of the battery box ive done a volt check on it and ist chuckin out around 13 volts under load [with the lights etc on] any ideas ?

[Jockney Rebel]

quote:Originally posted by mad mundy

Was up visit`n:Dbut also looking at RE.
re?

[Zed14]

r(real) e(estate) real estate land houses and all that stuff. will give you a call on fri mad im just been spending time with deb.

[shift1313]

if you can find alternatives then go for it. otherwise find a nice big heat sink you can use. some aluminum with alot of surface area.

[Jockney Rebel]

quote:Originally posted by shift1313

if you can find alternatives then go for it. otherwise find a nice big heat sink you can use. some aluminum with alot of surface area.
sounds like a plan ta matt ..ill try not set fire to my arse:D

[alfiestorm]

you might want to make sure your insurance covers you for fire.
It would be a shame to see all your hard work go up in smoke with no recourse (blimey that was a big word)

:D

[shift1313]

you could mount them in your grips for heat or right in the seat:)

[Jockney Rebel]

heated grips ..if i was still in blighty i probably would lol
i had a bit of a think about it and ill re mount them cos they dont get any airflow where they are and theres a nice big hole where my airbox used to live ill go down to my local "build it yourself space shuttle shop" and get some heat sinks see if that works the bike runs ok ..hunts a little at idle but then its 28 yrs old

[Jockney Rebel]

quote:Originally posted by loosebruce

http://www.vlc.com.au/~justin/about/bikes/honda/reg_replace.html
Was looking at this the other day, took a while to find again
ta brucey was a great help and ill keep it... but its not the reg/rec thats the problem

Frankie, if the Reg/Rec is over supplying electrickery to the cdi unit (not uncommon on Honda regs) then it will overheat. Can you do an amperage check on the connection between the reg and cdi (do your coils get hot?).

If it is oversupplying then you can either resistor down the amount of juice going to the cdi, or bypass excess power to earth.

I have an article here on DIY cdi units if you're interested in how they work, I can scan and email it to you.

[Jockney Rebel]

quote:Originally posted by chalk10

Frankie, if the Reg/Rec is over supplying electrickery to the cdi unit (not uncommon on Honda regs) then it will overheat. Can you do an amperage check on the connection between the reg and cdi (do your coils get hot?).

If it is oversupplying then you can either resistor down the amount of juice going to the cdi, or bypass excess power to earth.

I have an article here on DIY cdi units if you're interested in how they work, I can scan and email it to you.
ta chalk ill stick a me meter on the coils when the bikes back ends finished and ill have a look at that cdi article been tryin to find someone whod got round this prob apparently its pretty common i was gonna stick some heat sinks on em anyway

[shift1313]

chalk, do the hondas supply un-fused current to the cdi units? youd think there would be some sort of fault circuit for that. Ive never looked into it though.

You're right Shift, it's fused, or should be.
But the fuses are a max limit only, ie my kwaka indicator circuit has a 10 Amp fuse, but the circuit only requires 4 Amps max, even if both sides were operating at once it only requires 8 Amps max. If the Reg is putting out more than it should be it could still be under the fuse blow limit, but provide more Amperage than an older cdi unit can tolerate so well.
Electronic components can last for years/decades without any problem with them, but their tolerance for excess power loads will deteriorate over time. This is basically what happens with some Reg units, the circuitry for restricting power output deteriorates and they start to output more and more power.

[Jockney Rebel]

thanks guys my understanding of the magic of electrikery is limited to bieng able to do basic checks with a meter where do i do a check on amps ?from the plug on the back of the reg or what? cos the wires seem to be all the same colour

Find the wire that leads into the cdi, via the fuse box, ie the power input wire for the cdi.
The meter will have to be inline, not parallel as when measuring volts. And make sure the meter can handle at least 15 Amps or more. Take measurement very quickly, or you'll damage you're meter.
If worried you can get a current clamp for standard meters, which just clamps around the outside of the wire, much easier to deal with. Just make sure it is a Hall Effect sensor type, as the other type only do AC, not DC.
And you definitely wanna go AC/DC big boy :D

[Jockney Rebel]

the meter ive got is a snap on digital one ..thanks for the guidance ill give it a go m8