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I went to take my 04 SM out for a ride a couple weeks ago and had a misfire on the right cyl., opened bowl drains, plenty of gas. Pulled the pods, seems to be drawing plenty of fuel. Hand over back of carb, plenty of vacuum. Compression test, tests fine. Swapped ignition wires from one side to the other same side still misfires so thought I had it and just installed a firestarter, no change. Pulled carbs and disassembled and all seems clear and unchanged. Slide rises when engine is running. Pulled hidden filter just to have a look and it was clean as new. All vents are clear. I do seem to be getting spark on both sides when I pull the plugs and ground them. Squirrel condoms seem fine as do the intake rubbers. (sprayed carb clean when running, no change) Exhaust is also clear. I am considering the pick up coil but would that only effect one side? Left side fires as it should. Right is in and out and worse if I open the throttle, that lead to the carb work but don't see anything.

Prolly electrical. Looks like you've already narrowed the issue to: the misfiring side coil (possible); pick-up coil (less likely); or sparkplug (hey, it can happen, however rare). Good luck!

One other question...does the issue happen right from cold start, or only show up when the engine warms up (say about 8 - 10 min or so)?

No, it's right from cold. I know a coil or crank sensor can be fine cold and fail hot. I already changed the offending plug for another I had. I also swapped coil wires and sparkplug leads to eliminate a bad coil. That's why I came here to see what ideas you guys had. I'm sure I can figure it out but right now I'm stumped.

Well that is a puzzler; looks like you've ruled out almost everything electrical.

Only part left is the pick up coil but I would think that would effect both sides. My only other thought is a broken wire or loose connection somewhere. That would be miserable to find.

I am thinking since I did the firestarter I might do the TTP coils and wires and plugs just to make it all new even though the coil on the bad side worked fine on the good side. I am going to need coils anyway for the hardtail build if I ever get back to it. I have so much ahead of it right now it isn't funny. Breaking my wrist really set me back!

Just put 2 brand new plugs in to be sure that was ruled out and it made no difference.I checked the spark again and it looks good. Unfortunately I don't have an inline spark tester to watch it while running. I got plugs locally because I can get those on my commercial account for $5 for the pair instead of $30 from TTP. I might source HT leads locally too although that isn't the issue either since I took the lead from the side misfiring and put it on the side working and nothing changed.

Grasping at straws now, just pulled the valve cover and checked the valve clearances, all in spec. I also bought the coils and leads but I don't think that is going to fix anything. Next I might order a crank sensor just to complete the set. I also don't think that is the issue since that should cause a problem on both sides.

Hello- that happened to me - it was in the wiring going to that coil. Check the connectors plugging into that coil. Do a continuity check to wires with someone jiggling the wire. Bob

Thank you, I did inspect visually but I will do a continuity test as soon as I can, probably not until Sunday now.

What really gets me is it ran fine when I parked it right before I broke my wrist.

The bike is pissed at you! You can try running it in the dark to see if there is any sparks jumping from wires to ground.

Now it has new coils and wires too. Still no improvement but I have to say I didn't expect any.I have not been able to find any shorts or bad connections so far. I was looking at that carb again because I am at a loss right now as to the cause of the problem. So I started the bike and misted fuel with a spray bottle directly into the carb opening as I opened the throttle. There was no effect so it has to be electrical. New CDI, new coils, new plugs, new wires. Only thing left to replace would be the pick up coil but I really don't see that effecting only the right side. All connections and wires look fine, I unplugged the TPS just to see if there was any effect at all and there was none. It idles on both sides then as soon as I crack the throttle I loose the right side.

I am at the point of taking a sledge hammer to this thing and buying something else or just go back to riding the antiques, at least when they had an issue it was simple and usually fixed in a few minutes to a couple hrs. With this bike it seems everything is in order but the right side misfires as soon as I try and open the throttle. I have fuel, I have spark, I have air, I have perfect compression and all the new parts. I needed those same parts for my project so no wasted money anyway. I can't understand why it doesn't run, I have never been in this position before. I am usually fixing other peoples problems. I have plenty of other bikes and my BMW is even registered but I want to ride the Speedmaster.

Holy crap...at this point, I say try the pick up coil.

I think first I will run a wire directly from the CDI to the offending coil and a hot wire directly from the battery to that coil one at a time and see what happens. That way I can rule in or out a bad connection or broken wire.

I had a problem with the wiring harness connector to the CDI. Pull it out and go over everyone for corrosion. Also make sure each individual spade connector is tight. It's a tedious job but solved my problem.

Ian, I agree with you about the pick up coil affecting both cylinders, not just one. I doubt changing it would improve anything but don't change it until you finish the primary wire check along with the CDI connector check.

It would appear you've been very diligent and checked everything else properly. Swapping coils and still having the original right cyl miss usually confirms a problem with the CDI (replaced), CDI spade connector in the CDI plug, RH primary wires, RH spark plug(replaced) or RH HT wire(swapped). The only thing you haven't done is check those primary wires to the CDI which you are probably doing now or the connector itself (spade connectors for primary wires) as Mike suggested. Don't give up, this is one of those problems that causes you to second guess everything you know.

I think you are on the right track and anything else we say will be us just repeating ourselves. I can't think of anything else you can do. You checked for plugged exhaust, valve clearance, compression, even tried spraying fuel right into the intake eliminating a plugged circuit in the carbs... What else can you do?????

Thank you guys for trying to help, I have bypassed the harness now with jumper wires and still no joy. I have a new pick up coil on the way but I don't think it is going to fix the issue.I am at a loss, I am confident in my mechanical ability but this one really has me stumped. Never hurts to try and get a fresh perspective, sometimes you can be too close to the problem. I played with my old BMW a little bit today too, no issues with that thing, it never fails me.

I didn't check to see if each individual spade was tight but it is well greased and no corrosion at all in any of the plugs and I unplugged every plug in the harness to look. Only connector I need do are the leads concerning the right coil. I used jumper wires but if the spade was loose causing intermittent connection the jumper would do the same. I don't think that is it since if I just crack the throttle and hold it the right side is dead until I close the throttle again. Then it idles on both, if I crack it open hard to nearly full throttle I get sporadic fire on the right and that is what lead me to spray fuel directly into the carb opening thinking I just wasn't getting enough fuel.

Also- I had a carb act up on me causing one cylinder to cut out - listen to this - left over spalling (metal shavings) that are supposed to be removed after they make the carb - had gotten unstuck from one of the passage ends causing carb to cut out. Took a syringe full of alcohol kept squinting though passages with jets out etc. - wouldn’t believe metal shavings that came out. Been running my spare carbs ever since. Anything can happen with these things.

I shot fuel directly into the back of the carb and it made no difference so I don't think it's fuel delivery. I can also see fuel being drawn out5 of the main jet while running.

Also - I found so many faults in my wiring harness I ended up rebuilding the whole harness- removing all the lawyer stuff getting rid of the diode etc etc and solding all the connections adding thicker better wiring rewraping with harness tape etc. if I remember right found lots of problems at the connections at the cdi and right coil wasn’t grounding well. The worst harness connections I have ever seen. I really had a lemon for sure.

Should have seen the way the antiques were done, they pushed wire through the bullet connector and folded it over and plugged it together. No crimping, no soldering, nothing.

Very interested in how you get on with that replacement ignition sensor, a/k/a pick-up coil.

I'm interested too. I seem to remember early on, Triumph had a bulletin stating that the pickup coil clearance was originally too great at 1mm and was to be reduced to .8 (correct me if those values are wrong). I think Triumph stated this could cause a misfire?? Do you remember that one Ian?

YES Gregger, this was in the "Vault"...

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Pick-up coil Air Gap change
wojo #48250 01/01/2008 11:34 PM
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wojo
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The gap for the Hall Effect pick-up coil, located behind the right engine cover, was changed during production due to warranty issues, the following was sent out as a statement;

Affected Models: Bonneville/T100, America, Speedmaster, Thruxton and Scrambler.

Should a bike (see above) demonstrate faulty ignition coil type symptoms (most commonly an engine misfire), please initially check and adjust the ignition pick-up (IPU) air gap (we recommend an air gap of 0.8mm).

Since changing the IPU air gap in production to 0.8mm, we have had no ignition coil warranty claims.

Triumph manual, chapter 16, page 47 has the alignment procedure...

Thanks to members Sightglass for originally posting this and TonyG pointing out that it should be in the tech vault.

Last edited by moe; 03/04/2010 9:49 PM.

I wrote that down back when we first discussed it. I have it in the notes in the back of my factory manual. I did that adjustment on our bikes back then.

Taking forever for the pick up coil to get here. I order from TTP on the other side of the ocean and get it in 3 or 4 days but order from a little over an hour from me and it has been a week and still not here.

Usually Slow Postal Service. In days gone by, I would just drive over to buy parts directly, check out the bikes, & then stop in Cabelas on the way back.

Same here but I have too much other stuff going on too. My friend/boss gave me another truck, 86 Dodge 250 That has an issue. He was told it needs an engine but it runs fine but over heats. I just looked at it today and both rubber gaskets are gone on the radiator cap. But he also gave me another 360 I had to pull myself, so I did it today so he could scrap the truck. Too bad, that cab and frame are clean too like mine and it was a 350 with a dump body. I am part way through a tranny and gas tank job on my 96 GMC 2500 4X4. That needs fenders (I have) and I want to remove the bed and clean up the frame before I put the new gas tank and tranny back in. I also replaced the fuel lines, all the brake lines with nickle copper, and sending unit/fuel pump. That cab and bed also have no rust on them. I am half way through restoring another 8N tractor that is in my shop, all mechanical stuff done and 1/2 way cleaned up and painted. The there is my hardtail project and pouring a slab for a new 10,000 pound Worth lift I have, house needs a roof, etc... Dodge should be a quick fix since all I have to do is fix the over heat issue, it runs fine and body is clean except one small spot over the left rear wheel. If all goes according to plan should have the GMC, Dodge , and 8N done this summer, have to see what happens. I ended up working this afternoon, they got a truck wreck (tractor trailer, motor home, and a car) and only had 2 guys on so I did a winch out then had a state police wreck I also did.

I actually always stopped at Cabella's on the way home too.

Pick up coil installed, no change. I am stumped. Entire ignition replaced, can't find any shorts or bad connections, carb is fine as far as I can tell, getting gas to it, all passages clean, slide rises like the left. Shoot fuel directly into the back of it and no change. Compression is 150 psi on both sides. I am ready to put it in the back of the shop and get something else.

Wow. This is the first I have heard about something like this. Just a wild guess; I wonder if the wiring connecting the CDI could be bad.

Visually, no and I tried manipulating wires at all connections while running. It should run but it doesn't. I even bypassed the harness with jumper wires.

If I lived closer to you I would take that headache off your hands.

Not getting rid of it, I have every motorcycle I ever owned except 3, the minibike I had when I was 7 a dirt bike I had at about 10 and a 75 GT550 I traded for my Norton. I will eventually figure it out, just very frustrated, I never had an issue I couldn't diagnose in less than a day. That and when I swapped coils and the misfire didn't move I thought I had it.

Hello- if you have the colorized electrical schematic in the back of the Haynes manual that will help you figure out problem -when my America was doing same thing helped me traced down problems.With out that intensive schematic would have been impossible at least for me.

I bought an inline spark tester and I am not losing spark. Must be something in the carb I am missing I guess. Got my old BMW R50 out that I haven't had running in a few years even though it has been insured and registered. Got that running and went for a short ride. Not running quite right, carbs are pretty bad and I ordered new sparkplug wires. I also ordered new Chinese carbs because that is the only direct replacements I could find. The old ones are just beyond repair, they work but not right.

If you need carbs I have a spare set or two...the throttle plates may be removed...will need to look & see what I have.

If you have a spare set let me know, I don't know what else to try. Thing is I can see it drawing fuel, slide rising etc.. I could at least swap them out and see if there is any change. I couldn't believe what new carbs cost for my bike. I would be happy to send them back to you after I try, or I could send you what ever 2 I don't use. I can buy a generic CVK for $75 but the ones for our bikes is $700 to $1400 depending on the engine number. I have other carbs here but not that belong on our bikes, they all have cable operated slides and would take modification to mate to the engine.