5Th Gen Engine Miss/skip

Okay, I think it started last week. The bike (2001 VFR) sounded like it had a miss every once in a while at idle. It would just drop a cylinder, then come back. I started riding it and it was fine, then every once in a while, it would feel like it missed, but come right back.

A day or two later, it started missing and stayed that way for a couple of miles, then came back. This morning the one cylinder wasn't firing most of the way to work (8 miles). I've got about 100 miles on this tank of gas and at first I thought it might have been bad gas, but not so sure any more. I think it started when I had about 20 miles on the tank.

The bike has 55k miles on it. I just put new spark plugs in about 200 miles ago and had no problems up until now. The volt meter is still reading 14.3, so it isn't a battery/regulator problem.

I would think if it was an injector it would happen all of them time. How about a coil? Maybe one of the new plugs is defective?

Oh, and sometimes if I go to full throttle and can get the rpms up to about 8k, it comes back on. It is real fun in first gear! :wheel:

Anyone else ever have an issue like this? Is it bad gas or something electrical?

Since it has been kind of sporadic, I haven't tried to inferred the exhaust pipes yet to see if I can narrow down what cylinder is causing the issue.

Go back to the old plugs, and be sure your coils and wires are all ok. Maybe you loosened one while changing? Or one has bad insulation?

No need to use an infrared tool on the pipes, just use your hands. You'll feel which one is cold before you get close to touching it. But you'll probably see which one it is when you pull the plugs.

It was missing when I got home, so I hit them with the infrared. Looks like the right rear cylinder is really cold compared to the rest (like under 200�). Guess I will start there with the old spark plug and checking all of the wires/coil wires.

I'd put my money on plugs first, since it was recently touched (nothing against you!).

Might also say sticky/clogged injector but you ride the bike regularly, no?

Could be coil related but the last time I experienced something like what you described, it was due to a fouled plug. Could also be an incorrect plug gap? Iridium plugs come pre-gapped as the electrodes are easily damaged, you could have a poorly manufactured or otherwise damaged part.

Parts stores Drop and then still sell you the plugs they just dropped on the floor, a simple crack in the ceramic will make the plug junk. :ph34r:

Yes Seb, I ride it regularly. If I haven't been on it in a week, I start going through withdrawls. I've put 5k miles on my truck in the last year and 8,300 on the bike and only live 8 miles from work. :smile:

Okay, I changed out the 1 spark plug last night and it didn't seem to be missing when I fired it back up. I need to ride it though to be sure. Problem is the oil looks overfilled now and smells like gas (hopefully the cylinder didn't get washed down). I looked over the new spark plug and could not see a crack or any defects, but I guess that really doesn't mean anything. I had 37k miles on the old set of plugs and thought I would do the right thing by putting some new ones in. Guess I should have listened to Perham and let the old ones ride.

So much for the $8/each spark plugs and full synthetic oil change I just did 300 miles ago. :sad:

Did you check the gap on the plugs? I usually find one out when I do plugs.

Problem is the oil looks overfilled now and smells like gas (hopefully the cylinder didn't get washed down). :sad:

Oh No, bikes trash now you'ed better dump it!
I'll be right down with my trailer to tow that heap off and give you a few hundred to make you feel better! :ph34r:

Did you check the gap on the plugs? I usually find one out when I do plugs.

Just visually to make sure none looked way out of wack. They are iridium plugs, so I didn't want to stick a gap gauge in them and damage the tips.

Tell us what you are thinking Kal...

He read the seafoam thread and took to heart that seafoam is a waste of money and just used gas to clean his crank case out.