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Discussion Starter · #1 ·
I just bought a 95 Sprint and I am trying to get it run right. The bike will start and idle great but when I blip the throttle the tach will bounce up to 13k rpm and the motor will start to run rough. The tach seems to be accurate at idle. On the road at low rpm the bike pulls smoothly and then starts to skip and stumble as load increases and the tach starts to bounce and read very high. I did change the spark plugs and make sure the carbs are clean.

I have done many searches on this site and think it may be a coil issue and not the igniter or pick up coil. Any advise is appreciated.

Thanks
 

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The classic coil failure symptoms is misfiring up 3k or so rpm then smooth above with some tach erratic reading if the bad coil is on the same cylinder as the tach signal is derived from. But tach jumping to very high readings doesn't sound so typical to me. Your symptoms seem a bit different, maybe suggesting something else, perhaps igniter failure? (A cheaper & programmable alternative to Triumph's is available from Ignitech in the Czech Republic. More info in the T3 'Classics' Maintenance section.)

You could try swapping coils around & checking/tightening connections. Unplug & replug the Igniter connector a couple of times too - this helps to wipe the contacts.
 

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Discussion Starter · #3 ·
Thanks for the tip. I took a look at the wiring diagram and the tach does appear to receive a signal from the igniter. I will continue troubleshooting.
 

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The pickup coil resistance can be measured, and should be 530 ohms +/- 10%, but this does not sound like a pickup coil issue.

You can test the primary windings on the coil, they should read 0.63 ohms, but it isn't that helpful as a diagnostic, as the secondary high tension windings are the ones that normally have issues. I know most triumph dealers have a device that can test the secondary windings, but it can't be done with a normal volt/ohm meter (or there isn't a way that I know of).

I would purchase or borrow a coil and replace each coil one at a time to see if that will sort out the issues. If it does not, then my feeing is it would be the igniter. They usually run about $800 from triumph or bikebandit.com.

The igniter on my 96 trophy went around 2004 or so. It woould be rnning fine, then all of a sudden it would start sputtering and backfring, then it would die. When it would cool down, it would run fine for a while then the same would happen. I assume that igniter issues could appear in multiple ways.
 

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Check all of your coil and ignition connectors and ignition grounds before you spend any money.

Also ohm your plug wires. They are 5k ohm resistance as I recall.
 

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where abouts in the world are you? maybe tyou could find someone locally with known "good" coils and ignitor you could swap around?

does sound like an ignitor to me tho, because if your ignitor thinks you are doing 13k rpm, then it will deliver incorrect timing, causing the engine to bog down and die
 
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