I posted this exact post on another forum too... figure 2 places... different people, more answers, all the better right?


Hey all, I just bought a 1996 FXDS Convertible. It is a good looking bike, and it seems to run ok, but there are a few minor issues that I'm looking for some answers on.

First... Lots of decel pop! It's slow to warm up, and it pops on decel like crazy... I'm thinking it probably needs to be re-jetted (stock cv carb), but what do you guys think? It has a hypercharger and I believe screaming eagle accessory pipes... they're too loud to be stock but they do say HD on them.

Second... riding at moderate speeds it will sometimes cut out or miss, but the shop I bought it from said they replaced the spark plugs when I bought it, so I'm ruling that out... I'm thinking exhaust gasket leak, or an electrical bug... it's just a hiccup, but it only does it when holding a steady speed... increase RPM's and it doesn't do it at all; only when holding the throttle in one position at any RPM range.

Third... I noticed some oil around the carburetor, but it's not coming out of the airfilter. I'm thinking this is normal since there is an obvious breather hose coming from the crank case to the carb. It's just a minimal amount of oil... enough to catch some dirt. I thought it may have been overfilled but it appears it hasn't been after checking the oil.

Fourth... it has a base gasket leak, but it's minor. Should I bother getting this repaired anytime soon or should I just keep an eye on it?

Overall it runs fine, but I'm just looking for some advice on what to do here... I have yet to find a good indy shop to take it to in the Tallahassee area and will likely go to the local harley stealership and let them take a look at it for now... it rides great other than that. I noticed it idles at around 20 PSI so I'm sure it has an upgraded oil pump... might even have an upgraded cam too. It has an oil cooler on it that appears to be a factory HD accessory.

Should I be concerned about any of these things? I'm not new to motorcycles, not really new to harleys (grew up around them) but this is my first harley and my first evo motor... I'm not extremely mechanically inclined but I can turn a wrench and fix most of my own issues (I raced motocross for years).

Yes I know the battery box cover is missing... got one one order.

 

Beautiful bike! Not a big fan of the purple accents on the hypercharger, but I'm sure some folks will tell you to get rid of it. I like mine. I wouldn't worry about the base gaskets. Definitely pull the carb and check the jetting. Easy enough to fix and adjust the mixture.

 

From one 96 violet pearl model Harley owner to another welcome. This is THE ONLY forum you'll need to get all your answers. Definitely the best I've found with the most knowledgeable riders. Hope one of the knowledgeable ones chime in. I would play with your mixture screw to see if you can get it dialed in before rejetting. Had similar issues on my sporty when I went from a stage one air cleaner to a heavy breather. Small screwdriver, couple minutes and no more pop or stutter/hesitation holding rpm. Evo's are slow to warm up, and not warming them up before riding is what starts the base gasket leaks. Start it but don't take off down the road until you can feel warmth on the rear cylinder head. If the base gasket leak is minor and your not worried about it you can put it off just keep an eye on it. As for oil around carb it's typical with Harley's breather design. Usually full on your oil dipstick is too full I like to run halfway on the stick which eliminates the blowback or you can put on one of those fancy breather kits with the inline filter that will catch most of that. Again if it's minor it sounds pretty normal. Shameless plug of my violet pearl flstc or as I like to tell people is violent pearl.

 

JJ, looks good...I bet that color looks great in the sun!

 

Yeah it really pops in the sun. Here it is in partial sun. Don't have too many pics. Wife wanted me to take a pic of her on it.

 

Put a bikini on her and take some more!

 

Haha well I know some are down with this sorta thing but she's about 9 months pregnant right now so I don't think that'll fly. She's always been gifted in her upper region but wow those things could kill a man now

 

Well, I found out this morning that the original owner pulled out the aluminum plug for the air fuel mixture adjustment... I screwed it all the way in, and backed it out 2 turns and 3/4, and it got worse, so I screwed it out more and it got a little better but I still couldn't get it to run right... With work, I don't think I have the time to take care of this issue myself. I'm thinking its a gasket leak.

 

Another simple and free check is those pipes. Didn't even think about it on my last post but do those pipes have baffles in them. If they came without baffles (drag pipes), or the previous owner removed them you probably will never eliminate the popping without putting in baffles or changing to slip ons or full system with baffles. It's just the nature of the beast with straight pipes (the straight pipes also decrease performance if you're not running wide open throttle all the time). Not saying it couldn't be a gasket leak but I always look for the free checks first.

 

Nice looking bike! I have a 1994 fxds, had the popping on decel and the occasional cut like your describing. I think they call that condition "carb farts".

Anyways, jetting is the issue here. Most of the reading on forums have said to go with a 45 slow jet (idle jet) and a 180 main jet to cure your problem. It helped drastically with mine and the bike runs sooo much better now also. From the factory the bike is jetted lean (which is the most likely cause of your problem).

So you need to pull the carb for that. I bought my jets and other stuff from CV performance. They have a nice slide needle for the carb as well. They offer two needles, one is the old sportster needle that is a popular retrofit for more fuel (n-65), and they have their own "velocity needle" that is designed for our big twins. The velocity needle is shorter so it eliminates the need to shim the needle like some riders like to do. Based on how the needle is made it ads some performance to the bike as well. Go ahead and give the carb a good cleaning with carb cleaner while you have it off, and CVP's website has nice info on how to rejet. Good prices on their kits (all the most common parts) as well. I'm not affiliated with them, just impressed with their products.

My bike runs a lot better now with the re-jetting and the velocity needle, and the farts are gone, but some occasional faint popping still exists if I really get on it and let the engine do the braking (hard decels). But for normal riding, all my popping is gone. I tried larger jets in the slow and the main, but the 45 and 180 worked the best with 2.5 to 3 turns out with the adjustment screw. I am still thinking a 46 may be better for me, but bike is running sooo good and not to lean.

Anything more than say 3 turns out to get a good idle adjustment means you might need a larger slow jet and anything less than say 1.5 means you need a smaller slow jet.

In my reading (research), I have found that the most common problems that cause the popping are jetting, style of pipes and exhaust leaks. I had a little exhaust leak and cured that by removing the muffler clamps and mufflers, and cleaning the inside of the muffler connection and the outside of the pipe (actually used wire brush, fine sand paper and brake cleaner), then used ultra copper gasket sealer (only use ultra copper as all the others can't take the heat) and reassembled.

Just put the sealer on the inside of the muffler at the connection and slide it on the pipe (with the clamp on but loose) and get things into position (bracket and other pipe) adjust fit so everything bolts and lines up, but only snug the clamps and muffler bolts. Let the sealer cure for an hour or two and tighten the clamps a little. Let things sit for another hour or two and tighten some more. Wait all night (better yet 24 hours) and tighten the clamps for good. Torque on those clamps should be like 45 lbs so get em pretty tight.

The reason to wait is if you tighten too soon, you will squish all the sealer out and it will also not let any air in there for the sealer to cure.

Another thing to be aware of is if the stock muffler clamps are still being used, they need to be modified slightly. When looking at the clamp, the metal "hour glass" spacer in the middle of the clamp where the bolt passes thru has a hole that needs to be drilled out a little over size.

The reason is that "hour glass" spacer can fuse to the muffler bolt because the muffler bolt has groves in it. It is designed to do that or take a bite into the center spacer. After use the grooves bite into that hour glass and become locked, no amount of tightening will get that clamp as tight as you need it. So, drill out the hole slightly larger (only a little is all it takes), or remove the grooves on the bolt shaft from the bolt by grinding or filing. Sounds goofy, but when you take the muffler clamp apart you will recognize exactly what I am talking about.

Between re-jetting, sealing and re-clamping the mufflers, you have done all that you can other than checking for exhaust leaks at the head and the crossover pipe joint. The best tool for that is one of the barbeque extended tip bic lighter things. Put the open flame all around the area where the pipe meets the head and at the crossover pipe joint while the bike is running. If you have leaks you will see movement of the flame.

The popping is caused by unburned fuel in the pipes or muffler igniting when oxygen hits it. The oxygen can be provided by leaks in the system, or by certain "open" muffler designs. I have cycle shack tapered mufflers, and they are pretty short, so I figure it is just nature of the beast. But re-jetting and sealing leaks will definitely eliminate all or most of it.

Lastly, when I bought my bike it came with dynojet stuff in the carb, it was lean at slow and mid, but way rich toward high mid and main. Plugs and inside the pipes were black and fluffy. Now no residue and no signs of lean either. Just plain old clean plugs and insides of the pipes.

As far as the oil issue, isn't your bike a head breather? And do the heads vent to the carb backing plate? If so, is there a leak in the breather plumbing system?

Sorry for the long reply, hope it helps, YD