So I picked up this 94 1200, runs great when its running great. When its not running great its bogging, sooooo.

The last straw for a hard diagnoses is when it left me hanging in the middle of a not so great neighborhood around midnight. I had to blow into the gas tank to force fuel into the line/filter/carb.

So.

Since then Ive:

Completely cleaned out the fuel tank, petcock, put a new filter on it, put new fuel lines on it.

Still bogged out.

Changed the gas tank, updated the petcock, put the same fuel filter on it.

Still bogged.

Changed the fuel filter, checked the plugs, they were a little fouled so i changed them out.

Still bogged.

Opened up the carb, its clean as a whistle, jets are clean, float isnt sticking, everything looks good.

So I was at bike week and it was running great for a day and then it started acting up again. Plugs were completely fouled out so I went to harley and grabbed a new set of wires, new plugs, threw them on, bike ran perfect for about 6 hours. Next morning. Bogs out. So I pulled off the third brand new fuel filter, blew out the lines again and the bikes run perfect since then.

So my question is. What are some of your opinions on running without a fuel filter. I know the obvious issues but Im wondering if anyone does this besides me. The other question would be, what could possibly be going on that would make the bike perfect without the fuel filter if everything else looks perfect?

I have a lot of experience with both motorcycle and car mechanics and my mind is completely spent. Id prefer not to run without a filter for obvious reasons but Im at my whits end and the bike is running like a beast now.

Any insight is greatly appreciated.

 

I don't know what fuel filter you are using...but if it is a in line fuel filter you could try going to a larger one or a different type to see if that helps...if there is a screen on the petcock that should catch most all the trash and it shouldn't need a filter...I had a 93 and it didn't have a inline fuel filter on it..I say take it off and toss it....on another note you said it fouled the plugs.. how were the plugs fouled...were they wet?? or what.. you may have other issues that look like fuel filter issues such as the float needle is sticking or has some trash on top of it..I would pull the float and fuel line from the carb. and blow some air up through the hole that the float needle goes into and see if that helps...also I would be inclined to check the connections for the coil (the crimp ends sometimes go bad)and make sure they are all tight (including the bolt for the mounting of the coil..if I rememeber right the bolt acts as a ground source for the coil so you might want to take it out and give it a good look see...

 

Ditto on what Mrfisker said. I have a 2000 1200 with no inline filter. When it is running good what do the plugs look like. is it running really rich when it is running good? If it is your jets might be to big or check you air filter if it is soaking wet with oil from the breathers it would cause a similar issue IMO.

 

The first one was a harley filter, the second was a clear filter that I picked up at the swap meet, the third was actually a larger filter. The petcock does have a screen on it so I guess ill continue to roll without the in line.

The fouled plugs werent wet just black. The front plug was completely black the rear plug wasnt as bad but it was still pretty gunked up considering it was in the bike for only about 30miles.

I did all the carb stuff you mentioned, the float is fine, i swapped the jets out with a few other ones from when the ss shorty was put on the bike. Re tuned the carb and again, it didnt fix the issue.

Could it just be something as simple as the screen AND an inline filter? Its almost like the bike is starving for fuel but it flows nicely from the tank through the petcock, through the fuel filter and through the second line so as you can imagine, my mind is boggled.

Since not riding with a filter the bike as lost a small bit of pep, which my friend tells me is all in my mind. I was running NGK R plugs and now im running some oem harley plugs that were about 2$ a piece at the dealership.

The coil is fine as well, I had to wire a new gauge up (dont worry thats not the issue) so all of those nuts and bolts and nice and tight and nothing is bouncing around or causing a loose ground.

Even though the bike is running fine now its still something thats on my mind. Could just be some sort of weird freak issue.

 

if the plugs are black and sooty, it is prolly running rich, is it possible the the enricher is not all the way closed (off) when riding...also if the float is set too high that will make it run rich (and lose power) a lot of people don't understand just how important it is that the float is set just the right height... also try screwing the mixture screw in until the motor slows a bit and turning it back out slightly (that is called lean best idle) which is slightly different than rich best idle which is turning it out until the motor slows and then turning it back in until it speeds back up (rich best idle).....as far as plugs are concerned, plugs are plugs..buy cheap, buy expensive it wont make a difference except in your wallet....Oh, and is your air filter cleanish....

 

+1 - Black plugs don't indicate a "lack" of fuel, it's more like too much fuel.
A broken enrichner cable (they break internally) can cause you to be rich. It's not that a broken cable causes the loss of the "choke", it can cause it to be On all the time.

 

also the enricher circuit has a 'valve' in it that opens and closes depending on the if it is turned on or off...if the valve has a piece of crap in it, it may not close when off giving a rich mixture all the time...

 

Thanks for all of the responses, bikes been running relatively well so I kind of forgot about checking back.

In regards to the plugs, they're not wet, theyre covered in soot though. Basically look like a struck match.

The best comparison would be to a set of plugs that were running with the choke on for like an hour.

Running without a fuel line has been fine, im not too concerned with that anymore. The plugs did foul out again (black, dry) about two-three weeks ago, i cleaned them with brake cleaner and theyre doing alright. I have a few set on the way though just incase. Issues were the same, popping, bogging, like it was starving for fuel. The bike was running noticeably different when I was in Myrtle beach and it was around 85+ all week compared to it being in the 65-75 as it has been in NJ.

The only issue I saw with the plugs was that the bike definitely had some more pep when I was riding around with the NGKs and was noticeably less peppier when I went back to Harley oems (6r12) and I also put a set of oem wires on as well.

I believe the wires were resistor wires and the plugs were non-resistor plugs, or vice versa.

The only issue I am seeing now, which might just be my head messing with me, is that yesterday when I started the bike up, it was running a little rough so I pulled the choke up a bit and the bike just died. This has never happened before so Im starting to think that "valve" might be something to look into considering it didnt open like it should have. Other then that, when its on its on, bike runs really well 90% of the time.

The trials and tribulations of buying used...

 

i have a feeling it is your choke based on everthing that ive read and your responses. The cable is fairly cheap to buy and is one less potential issue. make sure your diaphams in the carb are pinch just for piece of mind also.