flyday58 Posted March 23, 2015 Share #1 Posted March 23, 2015 Discovered yesterday I'm only running on three cylinders. I'm using a TCI off ebay while waiting on Ignitech to replace my faulty TCIP4 but I don't think it's the problem. It runs great but the mileage hovers around 27, and the #3 cylinder doesn't heat up right away, exhaust pipe only slowly gets warm. Yesterday I pulled it out and started it normally, then shut it down, removed the #3 plug wire and started it again. It ran identical. I used an insulated screwdriver the lift the cap up and down off the plug. When I got near the top of the plug you could hear popping as a spark jumped from the cap to the plug. What's more, at some close gap between the cap and the plug top, the rpm suddenly increased and the cylinder started getting hot. Move the cap up or down, the rpm dropped, get it in the sweet spot the the rpm jumped up. Put the cap on the plug and the rpm never increased. Took the cap apart again but all was okay. Reassembled it and installed a new spare plug, and it ran at the higher rpm, but stumbled intermittently. So I think I've got issues with the cap. It was dark when I was doing this and didn't see any stray sparks anywhere around the plugs, wires, or coils. And with the cap on the spare plug before I installed it there WAS spark, not yelllowish, not a fat blue snapper like it should be. I'm waiting on COPs from a guy on the VMax forums, and between them and the replacement TCIP4 from Ignitech I should be in good shape. Anything I might have missed? Is the wimpy spark typical of the Yamaha TCI? Link to comment Share on other sites More sharing options...
syscrusher Posted March 23, 2015 Share #2 Posted March 23, 2015 I have one cylinder that seems weak when the bike getting warmed up but I haven't looked into it much. On the 93 the TCI isn't supposed to be prone to failure, I think. I'm interested to hear about the difference when you get the COP setup. Link to comment Share on other sites More sharing options...
MiCarl Posted March 23, 2015 Share #3 Posted March 23, 2015 Replace that plug. When a plug is fouled you can get it to work by giving an additional gap to jump - that's what you're doing when you lift the cap up. Link to comment Share on other sites More sharing options...
Godlover Posted March 23, 2015 Share #4 Posted March 23, 2015 When I had my bike apart I noticed that I had pulled a plug wire out of the cap. I also noticed there was no inner wire showing so cut back the insulation so that I had a wire sticking through. Was that the proper thing to do or should I have left it alone. Seems now that I am running on 3 cylinders as well..... Link to comment Share on other sites More sharing options...
Marcarl Posted March 23, 2015 Share #5 Posted March 23, 2015 Just for insurance and to be on the cheap, replace the wires and caps. If it hasn't been done before, things are getting pretty old and tend to not work as well as when they were new. It saves the guessing game and then you know where you are at. Link to comment Share on other sites More sharing options...
Venturous Randy Posted March 23, 2015 Share #6 Posted March 23, 2015 Anytime you have weak cylinder, it may be electrical or fuel. I have had corroded resistors in spark plug caps that did weird things. I also have had carbs so out of sync that one cylinder was not getting any gas at idle and had to be opened up to get warm. How is your carb sync? Randy Link to comment Share on other sites More sharing options...
syscrusher Posted March 23, 2015 Share #7 Posted March 23, 2015 It looks like the wires and caps were awful expensive when they were available. Was there anything special about them, or do you have any suggestions for an off-the-shelf replacement? Link to comment Share on other sites More sharing options...
Marcarl Posted March 23, 2015 Share #8 Posted March 23, 2015 It looks like the wires and caps were awful expensive when they were available. Was there anything special about them, or do you have any suggestions for an off-the-shelf replacement? Make a visit to your local NAPA or MC dealer,,, most will have what you want,,,,, wire s\b wire core not carbon core and cost about $5,,caps are going to be about $8ea I think. Link to comment Share on other sites More sharing options...
flyday58 Posted March 24, 2015 Author Share #9 Posted March 24, 2015 Anytime you have weak cylinder, it may be electrical or fuel. I have had corroded resistors in spark plug caps that did weird things. I also have had carbs so out of sync that one cylinder was not getting any gas at idle and had to be opened up to get warm. How is your carb sync? Randy Just got my Carbtune 2 weeks ago and set the carbs up properly, so don't think that's the issue. The plug is replaced, but again, it's still got an intermittent miss that I think is wire or cap related. Disassembled the cap and no corrosion, reassembled in the correct order. We'll see when I get the COPs installed. And the new Ignitech is on its way from the Czech Republic, so there's that, too. On the road till tomorrow night, I'll do some swapping on caps and wires to see if the miss moves. Link to comment Share on other sites More sharing options...
flyday58 Posted March 24, 2015 Author Share #10 Posted March 24, 2015 Just noticed I spelled "Duex" wrong in the post title. Should be "Deux". Two years of French in high school, there ya go. Link to comment Share on other sites More sharing options...
syscrusher Posted March 31, 2015 Share #11 Posted March 31, 2015 Does anyone know which caps to buy for the ignition cables and/or the resistance value? Link to comment Share on other sites More sharing options...
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