Since I bought my '01 Tin Cam 88 this year, it has been making quite a lot of engine noise, of which most is coming from the lower end of the engine, primary maybe. I didn't really notice it at first, but it was brought to my attention by other TC owners (which were more quiet). Some say 'hey, it's a Harley, it's supposed to be rough. Others scare me with assumptions the engine need a complete overhaul, if the crank isn't bent already.

Here are some of the details I already been through.

• There's 27.000km (about 17.000 miles) on the clock
• A Harley specialist has investigated the issue. Unfortunately we have parted prematurely due to a difference in opinion (the bike has been there for 3 months and I thought it was enough):
  • Specialist's opinion was that the milage was fair and probably hasn't been tempered with
  • Cam shafts and tensioners were checked, they were in good condition
  • Oil has been drained and checked
  • Oil filter has been cut open and checked
  • Cilinder heads have been pulled:
    • Intakes have been flowed by previous owner?
    • Pistons and cilinders looked good, although the pistons were a little wet. Probably because of a rich mixture (190 main jet with stock pipes)
  • Cilinders have not been pulled as far as I know
  • Gearbox was checked, piece of metal was found in the oil. It came of the 6th gear (Screamin Eagle gearbox), the sprocket has been replaced
  • Primary has been completely disassembled and checked
    • The bearing of the rear shaft has been replaced
  • The specialist said that the lifters were stuck? It's not sure if he freed them up, or just closed the engine again (at that moment we got into an argument about the time).
  • Spark plugs have been replaced
• The stock pipes have been replaced by 4,5" open pipes
• The engine does not use excessive amounts of oil
• The belt rubs against the rear tire when I reverse the bike. Forward it runs freely.

Here's a clip of the noise:
As I said, the specialist and I got into an argument (it wasn't pretty) and he just quit. Right now I am just riding it, as I am happy to have it back finally after 3 months. It runs great, but the sound has been bugging me every time I stop riding. Few options I was thinking of:

• Replace the 190 main jet with a 180 (because of the wet pistons)
• Check the lifters, maybe even replace them
• Something with the ignition timing?

Hope you guys can enlighten me, thanks

 

Doubt it's your crank...your bike has one of good ones. Did you check for exhaust leaks? Lifters are easy enough to change to eliminate that from the equation. It sucks not knowing what was done to the motor by the p.o. I woukdnt be able ride with my bike making some noise of unknown origin...would drive me crazy

 

I just sold my '02 FLHT that was TC88 but converted to an all bore 107" motor (124TQ/110HP) and it sounded very much like the video you posted. Honestly, I don't hear any noise that would give me cause for concern, particularly based on the information you posted on what has been checked by the tech.

Unless the lifters have been changed, they are the original "B" lifters; Delphi and the best the MoCo produced. The crank is a hot forged unit secured by a Timken left side crank bearing that makes the lower unit near bullet proof. The bike is carbed like my '02 so no EFI to mess with. Unfortunately, the ignition timing cannot be adusted unless you replace the OEM ignition module with a programmable ignition like the Daytona Twin Tec TC88 unit but if the cams are stock, ignition timing should not be an issue.

Like I said, I don't hear any alarming noise; the motor is an air cooled vtwin and it will not purr like a Honda; just the nature of the beast.

I don't recall off hand what the stock jetting for that carb is but if mileage is suffering, you might try a 185 main. I would also check the needle to see if it has been raised with shims. The idle does seem a little rough, like the A/F idle screw might need some adjustment. Check to see if the metal plug that covers that screw has been removed. Idle rpms should be about 1100, some say 900 but IMHO, that is too low.

It this point, I would suggest a compression and leak down test to confirm the condition of the top end. If that checks out, I think I would just ride the bike.

Forgot to mention that it is normal for the drive belt to track in toward the rear tire.

 

Thank you both! This is my first Harley, I always had Japannees bikes so i do have to get used to the roughness. I thought the stock main jet was 160, but I could be mistaken. It does 21 km to the liter, which is almost 60 miles to the gallon (which to me is pretty good?) I do think it could use some adjustment on the idle RPM indeed, it will only run idle fine (around 1000 rpm) when it's warm. But cold or even after being turned off for 15 mins, it will stall if not added a tiny bit of choke. As far as I could see the idle mixture screw has not been tempered with, so I could raise the idle to 1100 RPM.

I do expect the exhaust to be not fully air tight, it does puff and bang quite a bit when I release the throttle. Making the main jet smaller will probably make it worse?

The list so far:

• Check exhaust for leaks
• Some carb adjustments, idle (main jet?)
• Compression test
• Lifter check, maybe replacement

Any more suggestions?

 

Are you sure about your math? I get 50mpg which is no the norm; I would expect mileage to be more like 40-45mpg. Based on you comment the "it does puff and bang quite a bit when I release the throttle" it sounds like you should be focused on carb jetting. I am not sure what the stock main jet size is but pretty sure it's not a 160. I have found several posts on this and other forums that indicate the stock jetting is #45 slow and #190 main but I also see many 95" cammed motors also running a #190. So, JMHO, but pulling the carb off, cleaning it, making sure all jet passages are open, check float level, checking jetting, check needle PN and if shimmed, pull the A/F adjusting screw to make sure spring and o-ring are in place. Basically establish that the carb is clean, float level correct, jet sized are known, and starting over would be a good place to start. Float level can cause mixture to rich or lean.

The motor should start with enrichener (choke) but should run without choke within the first few minutes of startup. Full choke on start, gradually push choke in and by the time the cylinder heads are warm to the touch, the motor should run without choke. It still might hesitate a bit to quick throttle action but not for long. The motor should not "puff and bang" at all. The A/F idle mixture screw is not the screw used to adjust idle speed. The A/F screw is accessed from the underside of the carb and, in stock configuration, it is concealed by a small aluminum plug that must be removed.

Carb jetting can be frustrating but once one gets the hang of it and one understands the effect of making jetting changes, it does become less frustrating. The important thing is starting with a fully functional carb and know jetting baseline. Tuning then requires riding and making one adjustment at a time until satisfactory results are achieved. At the point, checking mileage and plug conditions will confirm that jetting is OK.

I have attached an article that should help understand carb jetting/tuning and a diagram for setting float level. Good luck.


http://www.nightrider.com/biketech/hd_cv_mods.htm

 

Sounds like a lot of noise coming from your primary. Chain loose?

 

Yes I thought so as well, but the specialist has checked that. Wouldn't hurt to check it again myself, although I don't hear the clacking sound during starting and stopping the engine, as you would expect with a loose chain.

 

Sounds like a broken horn rattling around inside the cover,

 

we have found on these early models that the compensator bolt on the crank has come loose a lot ...up to and including the 06' models till they change to the 96" motors .
the torque values where too low for this bolt (to the point that the rotor wobbles and wears out also) ...and the harley techs knew it too !!!

good luck ...

 

Those kind of things do take time to find with out a complete tear down right out of the gate. I'd say I have a 08 rg I've had for awhile because same problem. Had a tick. Unfortunately the owner didnt want to tear completely down. But with w little time I found that some one put the lower front rocker box gasket on backwards and it was venting out the front of the head. Good luck man