cdi GSXR Slingshot cooking it's CDI

[CoRSJohnny]

Soooo one of those annoying no clue questions guys sorry. 
90 gsxr 1100 slingshot which I commute eighty miles a day on. Without warning develops a misfire then cuts out. Half an hour later fired into life. Completes journey home. Following day the same. So suspect coils but funds don't allow for Dyna, go for R6 stick coils with new denso connectors. Bike revs clean put it back together and test ride, which starts well and ends with a misfire and engine cut out. CDI igniter box scorched and smelling awful. Check wiring order another CDI off fleabay. Plug in test ride and exactly the same again. Order CDI off flea bay and find bike charging at over 15 volts so get alternator too. Plug it all in check voltage and spot on, engine runs great put back together. Same again. I could have bought Dyna twice by now. New CDI plugged in engine sounds and revs awesome with stick coils. CDI heats up after five minutes. Charge voltage fine .... Any ideas greatly appreciated, be gentle I'm not overly technical as you can tell. 
Cheers. 

[johnr]

lesson number 1, before reaching for the laptop, reach for the multimeter. first thing to check on any bike when you have any problem thats remotely electrically related, check the charging voltage.  if a bulb blows, you get a misfire, anything electrical or electronic fails or behaves funny, check your voltage. sounds like your duff alternator  has cooked something, poss ignition pickups, poss one or more of your new coils.

[CoRSJohnny]

Fair point mate. I can't find anything irregular on the charging side now. I was told elsewhere it's the crimped joints when adding the loom for the stick coils, so a few things to check tomorrow. Cheers.

[johnr]

it might be worth going back to the original coils if only to simplify things, if youre changing stuff then its best to only do one thing at a time, youve got a misfire and a new cdi, new alternator and 4 new coils, so there are a lot of variables.

 

[cbr2gsxr]

CoRSJohnny, check and make sure you have a good ground connection coming from the battery to somewhere on the frame. I bad ground or loose ground can have adverse affects on the CDI!

[Fula28]

I would start at 15volt alternator, which you have changed allready the voltage regulator inside has problem am sure, check that plug and all the wires from it to battery with a multi meter.  And earths as said earlier on crank case and battery, clean em up shinney and a bit of where it bolts too. Be methodical an do each plug wire from alternator .

[CoRSJohnny]

Cheers Guys all stuff that I will try after work. The alternator regulator tested spot on, but the plug was damaged in transit so I'll look at that again. Quite possible I've knocked an earth loose somewhere too.

 

[Gixer1460]

Its all simpler than that! The stock CDI is looking for coil resistances of about 3 ohms.......stick coils are usually sub 1ohm and you've possibly wired them parallel so they are trying to draw approx 24A instead of the 4A as stock - no wonder they are getting toasted / ignition amps getting fried!

[CoRSJohnny]

Hehe no mate it's wired in sequence as per the articles I've read. But that was something I checked. The '98 to 02 R6 stick coils are about 1.2 to 1.5 ohms so in sequence should be seeing just under 3 ohm.

 

[Benjamin]

Hi guys. Please help me out. My gsxr1100 slingshot k is giving me trouble. I’ve got fuel and fire on all four cylinders but bike only runs on 1 and 2.

Ive taken out the carbs, stripped them down... no problems. Checked the valve clearance... no problem. Compression test... no problem. Serviced the bike... new plugs (tested them as well). Take. Out the CDI unit... seems fine. Unplugged all connectors and cleaned them out. Checked fuses... no problem. 
Don’t know what to do or check next... it’s confusing me. If I run the bike for a few minutes it kinda gets hotter on 3 and 4 but can still hold my hand on them... probably the other two dispensing heat. 
 

Please help me out. 
regards

Ben

[Captain Chaos]

plug leads on cil. 3 and 4 mixed up?

one coil fires 1+4, the other 2+3.

And welcome on OSS.  Please  post  pics of your 1100. We like pics.

 

 

[Oilyspanner]

Hello - need more details, is the bike std., what's been altered etc  really hard to know if ignitor box is fine, sometimes you only know because the bike runs fine with a different unit.

The photo would also help to see what might be at fault.