I have afunky problem with my '04 WG. It's carb'd, has V&HBig Radius pipes, and supposedlyhada richermain jet installed when the pipes were (pipes were on the bike when I got it).The bikehas been running great, but latelywhen I'm running at 65-75 for a while (20-30 minutes), the bike starts to surge and feels like it's starving for fuel. I can feel it cut out like it's going to shut down or something. When I pull to a stop, it's running like sh%^ and I have to keep blipping the gas for a couple of minutes to get things back to normal, then the bike runs great like nothing happened. This just started happening, and of course is in conjunction with my 10K service, which I did, so makes me think I did something wrong. I've changed plugs and oil, but nothing else that I can think of that would affect the motor. I need to clean my K&N air filter because the previous owner over-oiled it, but the bike's been running fine for months and just started running bad. The bike runs fine if I stay below 50mph or so and just putt around town.

As per some of the other posts, I'm going to pull the plugs and look at them - maybe one is cracked or the gap is off. I checked the gaps before installing them. Anyone have any ideas?Thanks in advance.

 

Also check the color of the tips of your exhaust pipes. They should be sort of a nice, aged copper color, like a used penny.

Oddly, it sounds like it's leaning out while cruising but then it sounds like it's richening up afterward. Perhaps a slightly sticking float? Maybe a few raps to the side of the carb with the handle of a screwdriver, and a few tanks full of fuel treatment are in order. I'd also check all the fasteners on the carb and intake manifolds. What happens if it's surging like that and you crack the throttle hard?

Z

 

Haven't tried that, but will do it next time the weather clears up and I can ride. I checked my air filter last night and it's pretty over-oiled. It's a K&N and I haven't cleaned it since I bought the bike last year, but it looks way too saturated - it's dripping oil. Funny though, the bike has run fine until now. I over-filled the engine oil by about half a quart when I did a recent change, but pulled most of that out - I originally thought maybe the engine was spitting oil into the carb and causing it to run bad at high rpms because the oil pressure was higher then...silly theory maybe, but the only other thing I did to the bike was change plugs. If I cracked a plug installing it, you would think it would run bad all the time. I'll also check my plugs to see if they are oil fouled, and the wires to see if they are tight.

What kind of fuel treatment do you recommend? thanks for the reply, I appreciate it.

p.s. - didn't see the comment about pipes - can't really check the color because the V&H Big Radius pipes are kinbd of a two wall design so they never blue - you can't see the actual pipe.

Paul

 

Paul:

Clearly, the first thing you need to do is read your plugs. If you're not sure how to do it, take a look at this post and consider doing a further search here an elsewhere on the web. When I mentioned checking the pipes, I meant for you just to look inside the tip of the pipe (where the exhausr exits the pipe) to determine if the exhaust gasses contain a lot of unspent fuel (black) or not. When I purchased my used Evo Big Twin, the inside of the exhaust was black (almost sooty). Once I rejetted, it turned that nice copper color.

As for fuel additives, I doubt you need it but it can't hurt. Sea Foam seems popular, as does HD's additive.

Chuck

 

Chuck,

I know how to read plugs- that's the project for the weekend - I'll check the pipes too. I was thinking you meant the outside wall color. Will try the plugs, cleaning the air filter, and checking the exhaust before I do the fuel additive. Thanks again - will post back in a few days to let you know how things went.

Paul

 

Paul,

Glad you're on top of the plug reading thing.

Another point I meant to make: that whole business with your air cleaner seeming over-oiled (combined with your comment about having overfilled the crankcase by 1/2-qt) leads me tothink that your oil saturated air filter might have gotten that way from blowby rather than from excessive oiling by the PO. I've never had a Twin Cam but I think they're suceptible to the same sort of overfilling blow-by (through the crankcase vents that dump intothe air filter)that Evos are susceptible to. Also, while surging usually indicates a lean condition, I had an experience where my Evo was surging while running too rich. I wonder if your filter could be so choked with oil that it's restricting air flow and causing a rich condition, making your plugs foul. That might account for the need to clear the plugs by revving the motor for a while.

I doubt this is related to the fatter main jet you have, since the problem's not occurring at WOT where the main jet is running things. I think the throttle position where you're experiencing the problem would point more toward the needle jet.

You may have already heard of this page, but here's a link to a Carb. & Fuel System Troubleshooting Guide that you might want to check out. The sight also contains good general carb information.

I don't know, I'm no pro at this, I'm just thinking aloud with you.

Chuck

 

Chuck,

Thanks for thinking out loud - I do the same thing, helps troubleshoot! Will check out the carb section. Thanks again.

Paul

 

OK, here's a bit of an update: checked the A/C element and it was very oil soaked. It's a K&N, and the oil wasn't red, so I am assuming it was engine oil from my little over-filling screw-up. I cleaned the filter using the K&N filter cleaning/recharging kit and it looks good now. Checked the plugs, and the electrode (bent part?) was a good color, but the ceramic was white. I have only had these plugs in for about 200-300 miles though, so not sure at what time they start to get that tannish color. Wasn't able to check the tightness of the intake hardware because I'm not exactly sure how to get to the bolts without taking the carb off. Maybe I can't and I stated the obvious without knowing it...

Anyway, pulled a bit more oil out with my trusty turkey-baster and I now have 2.5 quarts, which I should have had in the first place had I not been an idiot. Ran the bike this morning around 70mph and it ran great. The pipes are black, not coppery in color, but that might be because the bike may have been having trouble breathing. Going for a ride Sunday - about 150 miles or so, and will check everything when I get back. So far, so good, will keep my fingers crossed...

 

Sounds like you might have gotten to the bottom of things. Glad to hear it. It took quite a while after my rejetting for the pipes to turn from the sooty black color to that dark copper so don't let that bother you if it doesn't happen quick. Maybe search the forums (or the Web) for a good photo guide to reading plugs if you're not 100% certain what you're seeing (I never am!). If she runs well, gets decent mileage and the plugs look good then you're good to go!

Z

 

Z,

I think so - the scary part is I bought the bike from the stealer with the V&H pipes on it, and the salesman said the bike was re-jetted. When I changed the plugs, the originals didn't look like the bike was running lean, so I am hoping the bike was actually re-jetted. I'll check out some plug reading info on the web - it HAS been a few years since I've had to read plugs. I get around 47 mpg, so that's pretty much in the range they told me. Thanks for the reply, appreciate it.

Paul