Wooster Posted April 1, 2022 Share Posted April 1, 2022 There are two different types of coils - those designed for a CDI (capacitor discharge ignition) and those for a TCI (transistor controlled ignition). A CDI isn't really bothered by the type of coil but a TCI is. If you use after-market coils designed for a CDI and you have a TCI - you will destroy the TCI. A simple check is to measure the primary coil resistance. About 2 ohm and it's made for a CDI. About 4 ohm and it's made for a TCI. Check your owners manual or the service manual to see what ignition you have. Lot's of Yamaha's use TCI. This comes from a bitter experience. I needed new coils for my wife's XVS250 and an after-market supplier sold coils with words on the website saying "These coils are compatible with your bike". Not knowing anything about CDIs or TCI's, I fitted them. They were 2 ohm and made for CDI, the bike has a TCI. About 200 miles later the bike suddenly stopped - no sparks. The only fix was a new (TCI) ignition module at vast expense. (And another set of - correct - coils, of course.) Be very, very careful about the coils you fit. Link to comment Share on other sites More sharing options...
Moderator Snakebite68 Posted April 2, 2022 Moderator Share Posted April 2, 2022 Interesting... The obvious question is: Was it a reputable website? Link to comment Share on other sites More sharing options...
jimmy Posted April 2, 2022 Share Posted April 2, 2022 Hey bud, sorry to read of your experience but thanks for posting as an experience to others. If I am needing stuff for a bike, and unsure of the specific details I'll search the relevant forum posts and if need be, start a new thread. Your post will help others so you may take a small consolation from that. Happy biking Link to comment Share on other sites More sharing options...
Wooster Posted April 2, 2022 Author Share Posted April 2, 2022 13 hours ago, Snakebite68 said: Interesting... The obvious question is: Was it a reputable website? I thought so. Trustpilot gives them a great score. motorcycleproducts.co.uk 9 hours ago, jimmy said: If I am needing stuff for a bike, and unsure of the specific details.... Yes, of course. But I didn't know about CDIs and TCIs - I was just buying coils. I had no idea there were two distinctly different types. 9 hours ago, jimmy said: Your post will help others I hope so. Is there a 'better' place on this website where it would be more prominent? 1 Link to comment Share on other sites More sharing options...
Moderator Snakebite68 Posted April 2, 2022 Moderator Share Posted April 2, 2022 5 hours ago, Wooster said: I thought so. Trustpilot gives them a great score. motorcycleproducts.co.uk Right, then did you contact them? Telling them that their posted information was incorrect and that their recommendation caused damage to your bike (showing proof (probably in the form of the bill and a covering letter from the garage))? If they ARE reputable, they will (at the very least) refund you for your purchase, and ideally do that AND compensate you for the repair bill... Link to comment Share on other sites More sharing options...
Wooster Posted April 3, 2022 Author Share Posted April 3, 2022 10 hours ago, Snakebite68 said: ...refund you for your purchase, and ideally do that AND compensate you for the repair bill... After countless emails they refunded the purchase price and compensated me for some of the repair bill. (I'd contacted Trading Standards, Citizens Advice etc, etc.) They have since removed all 2 ohm coils from any Yamaha they've listed. 1 Link to comment Share on other sites More sharing options...
Moderator Snakebite68 Posted April 3, 2022 Moderator Share Posted April 3, 2022 2 hours ago, Wooster said: After countless emails they refunded the purchase price and compensated me for some of the repair bill. (I'd contacted Trading Standards, Citizens Advice etc, etc.) They have since removed all 2 ohm coils from any Yamaha they've listed. Probably as good as you could have expected..! Link to comment Share on other sites More sharing options...
Moderator Cynic Posted April 3, 2022 Moderator Share Posted April 3, 2022 Would not trust trustpilot as far as i could spit, i used their site to try and put a 3 star rating for services from red driving school that were frankly, shite. Could not post it, it was blocked and i received an email to contact red driving school. They wont post less than perfect. Link to comment Share on other sites More sharing options...
Wooster Posted April 4, 2022 Author Share Posted April 4, 2022 19 hours ago, Cynic said: Could not post it, it was blocked Perhaps that was the way RED ran it. I've posted many rubbish (1 star) reviews - British Gas, SSE, TalkTalk etc Link to comment Share on other sites More sharing options...
Moderator drewpy Posted April 4, 2022 Moderator Share Posted April 4, 2022 CDI's were only fitted to 70's bike as it means capacitive discharge Ignition. as fitted to the early kawasaki KH range. TCI is transistor. Your point is still relevant as ignitions will be built to expect certain ohm readings from coils. there is a third ignition which is Digital controlled ignition. maybe that was what you were referring too? Link to comment Share on other sites More sharing options...
Wooster Posted April 5, 2022 Author Share Posted April 5, 2022 19 hours ago, drewpy said: CDI's were only fitted to 70's bike CDI's are fitted to most modern bikes. As far as I can tell, it's Yamaha who use TCI more than most. 'Digitally Controlled Ignition' is a phrase used to describe the multiple functions now handled by the ignition system. The 'DCI' will (still) use one of two systems to produce the pulse that is fed to the coils. 1) A capacitor charged up and discharged by a thryistor or 2) Microprocessor controlled Darlington transistors. These are the only two systems available. A lower resistance coil will charge up the capacitor more quickly or overload the Darlingrton's - depending on what system is used. Link to comment Share on other sites More sharing options...
Recommended Posts