Dieseling / Lifter chatter

How serious is Dieseling and lifter chatter other than annoying me to death?
My bike just started about 500-1000 miles ago. Not too bad when solo but 2 up sounds terrible. I do most work on my bike myself but have been afraid to go into the engine. I have changed out the starter, pulled the clutch basket, oil changes, things like that but the engine scares me. Is this a difficult repair? What could be the cause? I have looked in the manual but it doesn't seem very clear on a possible cause. It list several things to check but not really how to check them.

The bike is a 99 Fatboy. 27000 miles. Last of the evo's not twin cam.

Thank you for any advice you can give.

I would try a different brand of gasoline and may be a higher octane

Hotroadking,

Thanks for the reply. I think i may have communicated my problem incorrectly. My bike doesn't keep running after it is turned off. I am getting a lot of lifter chatter on acceleration, especially when riding 2 up, or even going up slight hills without downshifting. So I put dieseling because it sounds like my diesel work truck. clatter clatter clatter! It probably isn't load enough for anyone off of the bike to hear but sounds loud to me.

Ruffrider,

I already run 93 octane. I have tried several different stations. I have always ran 93 and this is a relatively new problem. Thanks for the suggestion though.

What gear you in and how fast are you going when you hear the noise??

Sounds to me like "pre-ignition", one of the causes of "pinging". The other is detonation which sounds the same but the cause is different. And I see you're down there in South Carolina, where it do tend to get a bit toasty ;-)}

If the carb is not jetted/adjusted correctly and/or if you've got leaky valve seals (fairly common problem) then over time you'll get carbon build-up on the spark-plugs, piston tops, valves & combustion chambers. Especially when the weather's hot & you're riding 2-up, those deposits will get to glowing red hot on the compression stroke & ignite the mixture before the spark-plug fires. If carbon build-up is indeed the problem (I'll bet it is) & you don't solve it, you'll end up burning the edges off the valves & blowing holes in the top of the pistons.

What do the spark-plugs tell you? You can see evidence of carbon build-up on them pretty quick. And you can blow it out of the engine pretty easy too, with spray Gumout carb cleaner, auto transmission fluid in a squirt can, or even water in a spray bottle. When the engine's completely warmed up, pull the air-cleaner & spray any of those 3 thru the carb with one hand & tweak the throttle with the other so the engine doesn't die. With a free-flowing exhaust, bits of carbon will come flying out & with ATF you'll smoke up the neighborhood too, but it also lubes the valves nicely & it's loaded with detergents.

Don't go crazy with it or rev the heck outta the engine, but that'll loosen up carbon deposits & blow 'em out. Once you've got the engine cleaned up inside you can set about tuning it so it doesn't carbon up again. Although if it is bad valve seals, those will have to be replaced or it will do it again. You may be able to tell if it's too much gasoline or too much oil by the spark-plugs, but it could be both. Blow the carbon out then put in a new set of plugs & check them after 100 miles or so.

Lucifer,

Usually 3rd, 4th, 5th. and between 45-60 mph.

Art,

I jetted the carb last winter with the kit sold on this site. Before it was way over jetted and the plugs were black and sooty. Since jetting the carb following the dirrections with the kit,the bike has run much better. I changed the plugs about 2 months ago and they were a little chalky, which i had been told is how I want them. However if you put your finger in the end of the pipes it is still black and sooty.

That was a lot of good info in your post and I will definately try that this weekend. Hopefully it will work. I called the Harley shop to get a rough estimate on them fixing it and it was over $500 on the low end and close to $1000 on the high end. Plus a month wait. Way more than I can afford and way longer than I would like to wait. I ride almost everyday, my other ride is a jeep that gets a whopping 15mpg.

Hotroad,

At the same time I done the carb work I added a Arlen Ness Big Sucker air cleaner. Other than that just a new starter and an oil change. SAE 50 Penzoil.
No other mods.

I was thinking you may have been lugging the engine a bit, accelerating with the revs to low for the gear you're in.
I'd go with what Art says and clean er up inside, could be a combination of carbon built up and a little lugging, with ambient temps on the hot side,carbon and low revs,could be causing the spark knock.

I love cleaning carbon out of an engine. Give it to me. I'll do it for free

My method of course is Wide Open Throttle to as fast as you can handle it and for as long as you can handle it. Should be clean as a whistle after that.

Have you ever adjusted your chain for slack in your primary. If your bike is running good other than the noise, then this will probably be your problem. If it is not running well and you have noticed any power loss, then it could be your lifters and cam. Whatever it is you need to fix now, because fixing later could be expensive. If you have a digital camera, you could take pics as you break it down, then if you can't finnish right away you will have pics to help you put it back together. Good luck with however you handle it. Keep the shiney side up and the rubber to the road.

I checked the primary chain when I replaced the starter last month. It seemed to be how the manual says it should be. I have no doubt that he noise is coming from the top end of the motor. I am hoping the suggestion on cleaning the inside works. I will find out this weekend and post on here what happens.

Art,

I tried the Gumout carb cleaner and it is a little better. There is still pinging but not a severe as there was before. I may try one more treatment. Thanks for the info.

If you get a lot of carbon build-up over time you'll want to do it more than once, but if you get some improvement each time & the spark plugs are looking good, you can usually clean the combustion chambers & piston tops up pretty good without pulling the heads. Then you want to determine what caused the build-up in the 1st place & double-check the timing too.