Cylinders dropping out

Went on a long ride last night and halfway home (in the middle of nowhere) the engine starts to lose power. It was intermittent. It felt like the engine was being strangled, then all of a sudden it immediately clears and my arms are pulled out of the sockets.

I thought it might be bad gas as I just filled up, but I'm inclined to think its electrical as it would happen like a switch was being turned.

Two recent electrical changes I have made are, spade connector from relay to coils broke, and I repaired it good. Second is the electronic pickups; the left pickup looks like it hits the lobe and the right has a 1/16 clearance. The bike ran fine but I was concerned, so I spaced the pickup away from the lobe with some very thin washers. That was 7 days ago and 200 miles, bike was running great after the spacing. I don't think that's it unless the screws have fallen out. I'll check today.

Could it be the pickup(s) or ignitor failing?

Maybe something temporarily blocked the fuel flow?

I do need a new inline filter, I can see some crud in it. I'll replace it. I'm just worried about being stranded if I don't fix what is wrong the first time. I'll pull the petcock and check it too. But I still think it's electrical.

I'll check the manual and see if there's any test for the pickups and ignitor.

Kent, I am sure you have been around long enough and are savvy enough to know there is absolutely no way to use the info you put into the post to diagnose the problem. You really need to figure out which cyliners are not firing when they cut out to get a line on which way to go as far as "fixing" the problem. When a fuel filter gets dirty, the bike will starve for gas and the bike will just not want to go... when a coil or pickup coil or igniter go, the bike will run raggedly. In both cases, they can run bad then kick right back in. I can pretty much tell the difference having exerienced both types of symptoms but if you can't, start by replacing the fuel filter. You probably already have an idea of the condition inside your gas tank and will be in the best position to know if removing the petcock for a possible de-gooing is needed. Most tanks will pick up some solid sediment and it doesn't do any harm to dump the gas and clean the screen.

As far as the electrical, if two cylinders drop out and then kick back in, it could be the coil, connection to the coil, the pickup coil or the igniter. You didn't mention whether this was a stock electronic ignition or Dyna S... if stock, and the pickup coil appeared to be bent and you had to mod it to make it orient correctly, I would start looking at eBay for a replacement. I am not sure if the igniter box on the 650 is the same as the 900/1000 but I would pick another up from eBay as a "spare" and recheck wiring connections; especially those that were worked on recently. SOLDER wherever possible!

I bet there was absolutely NOTHING in my post you hadn't already thought of so just be patient and fix everything that could cause the problem whether it needs fixed or not due to the non-constant nature of the problem especially since you are worried about reliability. Good luck!

I replaced the points with 550 pickups and 750 ignitor last year. Stock coils. Stock advancer in good shape, not rusted. Springs are good on it. It has been running great for thousands of miles until Saturday night. I can't find any tests for the pickups or ignitor. From some of Lou's old posts, you need to cut open an ignitor to test it, or have some fancy a$$ machine. Probably cheaper to ebay a spare ignitor for now.

I did a few things Sunday. I checked the coils and got great primary and secondary readings within range, but that doesn't mean they aren't dropping out when hot. No visible cracks on them.

I replaced the plug caps with new ones. Plug wires are original. Last year the wire ends were snipped to get a cleaner connection.

I replaced the inline fuel filter.

I removed the petcock, it was clean and the tank still looks clean and new inside from the acid wash 2 years ago.

I took a couple 20 mile rides Sunday and it didn't drop out, maybe it was the fuel filter. The other night I was worried that if I popped off a plug cap to see if a cylinder was dropping, I wouldn't get the bike running again. I was really limping the last 20 miles with it never getting over 4 grand, and then it was like someone turned a switch and it was running great to 7-8 grand, then dropping out again and not getting over 4 grand. I really think it's electrical.

Over time I have replaced many connections and wires, some are better than others. Some connections looked a bit ragged so I temporarily wrapped some electrical tape on them to get by until tonight. But they are just crimped, not soldered. One at a time, right? I'll replace the connections and search for a spare ignitor.

Thanks WG and steell.

Post edited by: OKC_Kent, at: 2006/10/02 11:14

That is odd... there are definitely multimeter type tests for both the ignitor box and the pick coils in the KZ1000 manual. Since you have a non-standard ignition, you might want to find a 550 and 750 owner to type up the directions for testing those two components. If you replaced the gas filter and nothing advserse has occured, that MIGHT have been the problem but I would look at connectors for sure tracing ignition connections from the pickup coils to the ignitor to the coils as well as the wires that power the coils... anyway, good luck!

I have a FSM & Clymers manual with a supplement for the newer 650's with electronic ignition. It didn't have any test procedures. Maybe the FSM for the newer models has it, my older FSM doesn't.

Some of those ragged connections in the reg/rec area and ignitor I made were crimped, and I saw one where the insulation was broken from the crimping process, and it looked darker. Maybe it was shorting out from there..?..I wrapped them up in electrical tape and took those two rides yesterday, the problem didn't pop up, maybe that was it?

Tonight I'll strip them apart and solder them up, heatshrink them good.