Little background. When I bought my road king my dad, who live out of state, shipped his bike to me so we could ride together when he comes to visit. It a 96 or 97 fatboy(I know I should know what year it is but I dont and I think they are the same for those years), its basically stock as far as I know with Vance and Hines Long Shots and a little over 24K miles Anyway, it sits alot, my fault, but when I can ride I ride mine. Hes coming out next weekend so I wiped it downs and took it for a spin tonight. I have two issues (theres never been any with this bike except maybe a little cold natured)
1. Slight wobble at 70 plus. I did put some air in the tires. about 35 PSI, maybe too much?
2. the bigger issue. Its coughing and sputtering almost like its running out of gas. It usually does this until it get warmed up but I couldnt get it to go away in about 30 mile of riding. It accelerates normal but when cruising 3rd or 4th gear it kinda sputters.

I know its long winded and maybe a little vague, but I dont get to ride w my dad much and I just want us to be able to enjoy the ride and not have to mess with his bike.

Any suggestions?

 

So a handfull of people have checked this out but no info? I know there's some guys on here that can help out. I always get my questions answered regardless of how stupid they are lol

 

Well I'll give it a shot, from your description of the problem it sounds like it may be a running a bit lean at cruising speeds.
First of all ask your father if he ever noticed that happening when he rode it where he lives.
If his place is at a higher altitude then yours the lower atmospheric pressure of the higher altitude may mean that the carb is setup a touch too lean for your area.
Not sure (it depends on the carb maker) how you would need to richen it up, it may only need a minor tuning adjustment or a new (larger) main jet.
But that would be my first guess for that kind of issue.

 

I have a 92 fatboy, similar to the 96. In 97 they changed some things but still very similar. Sounds like there might be some settement in the tank that gets stirred up as your riding it. Of even a partially clogged fuel filter. Could be plugs, old gas, carb gummed from sitting??? The possibilities are endless. As for the wobble, sounds like a tire is out of balance. My bike has a shimmy at around 3 grand that goes away. Seems like ALL vehicles have shimmy or wobble at some speed.........Hope you can figure it out in time for your ride.

 

I don't know if the bike is injected or carb. Once my bike sat most of the season and thru winter because I had surgery. When I stated riding it again it did what you describe. The problem in my case was the rod that makes the acc.pump squirt corroded and would not move freely. I cleanded it and the problem went away. I kinda sounds like a fuel delivery problem. If it is a CV carb I have read post on them on here ,but I don't know much about CVs. You could use search or someone should come along soon. I think you are a little low on air pres. I run 40 rear and 38 front. If its out balance you could try Dyna beads

 

If it is accellerating normal, you are getting gas. It should be a CV carb, has a black round cap when looking over the top of the air breather cover, the carb is running lean and the long shots and colder weather are factoring in.

If you are running 1/4 throttle down the road, you are probaly still on the low speed jet, possible repair is to pull the bottom of the carb off and check for dirt and bump the low speed jet to the next size, when you pull the choke/enrichener on a little, does it clear up the sputtering?

 

First let's talk about the wobble, try 38in the front and 40 in the rear. If the pressure was low and it sat for a while you may need to ride it for a while to get the tires round as the can get a flat spot from sitting with low pressure. Next let's do the simple stuff first for the coughing and sputtering. First try a new set of plugs and wires, if the plugs are in need of replacing they can cause the symptoms you describe and the wires are probably original '96 vintage. Then if you are comfortable with doing a little work on the carb (if you have one). Take it off following the instructions in the manual(if you don't have one you need one!) and spray some carb claener in the jets. Then replace the needle with one from a sportster that has no accellerator pump and remove the plug covering the idle mixture screw and set it at two turns out, that should go a long way in getting rid of the coughing and sputtering. Hope this helps, if you need the part number for the needle send me a message and will send it to you.

 

A further tip regarding your tyres is to check the date they were made. Amongst all that stuff written on the sidewalls is a code that will tell you when your tyres were made (see this website). If they are seven years old or more replace them with new ones and, as John suggests, use the correct pressures. If you are heavy add a couple of extra psi. Also if you change to a different brand, check that website, as some use different pressures to the stock tyres. If you don't ride the bike very often fit a superior brand such as Avon Venoms, which will give a better ride and grip.

 

Yes, follow Miacycles instructions on installing the sportster needle, I mentioned a low speed jet change but the sportster needle will cover a wider range of repair for your problems.

 

All good suggestion thanks guys. The low speed/high speed jet theory sounds like it might be my issue, ill try what you guys suggesting tonight. Somebody mentioned colder weather, I wish! Its still in the mid to upper 90s here. I may go ahead and replace plugs and wires for good measure. Thanks for the help!