I'll start with some background info. 2001 Fatboy with stock 88" when I purchased. Did SE204 cams and about a year later did 95" BB kit with beadwork. Bike ran good - very smooth, but lacked low end torque I wanted. Swapped out 204's for TW6g cams and Miller heads for more compression. Same low end torque issue. Changed exhaust multiple times.

So last year, I try again - this time get some different heads that retained stock exhaust valve size, thinking the bigger valves were hurting low end. Heads had Jim's .600 valve springs, as I wanted to try cams with more lift. Installed heads and immediately noticed a lot more valve train noise and vibration (TW6 cams with .510 lift still installed). Swapped out cams to HQ-0039 cams with .580 lift and earlier intake closing. Heads were milled for 10:1 CR and bike was tuned. Low end torque was much better and bike still pulled into upper rpm's. Engine noise was very noisy and vibrations bad. I had rocker bolt covers on bike, and they vibrated loose and fell off within a couple miles from house. I pulled rocker covers and grinded some of the webbing hoping extra clearance might help. Initially, I thought it helped, but noise is still bad.

I have not been able to ride much as I had an electrical problem it took awhile to figure out, but recently got it running. Went for a ride last weekend and had oil leaking from pushrod/ head gasket area. Reseated pushrod covers several times, making sure I had a good seal and leak looks like maybe coming from the head gasket. Starting to think the engine vibration may have caused bolts to loosen, but have nott had a chance to look - been too busy at work and home.

Could the higher lift springs be causing this much extra noise and vibration? I know selecting valve springs can get pretty technical and beyond my current knowledge. I would also suspect the higher lift cams, but it did the same thing with TW6 cams. I have tried adjusting pushrods a few times - turning a couple more flats - no help. Noise and vibration is not rpm specific. I have also read where people say you need a special tool when re-installing rocker arm assembly to ensure it is positioned correctly. I did not do do this - just followed manual. Any ideas to look at? It would be nice to reduce the engine tapping, but I can live with that. The vibration worries me.

Anybody out there in San Antonio/Austin area that might be willing to take a look at it, or good cheap mechanics in area? My wife is ready to kill me over the bike if I throw much more money at it.

 

Any ignition mods? Also, what about your lifters?

 

Other mods include stock TB bored to 48mm, coil relocation kit, marelli high flow injectors - all on bike prior to this problem. These heads were milled to 82cc, old heads were milled to 79cc with no extra noise. Lifters are stock B lifters with 21k miles. Wondering if when I put rockers back on, if they did not get centered exactly and pushrods are now making contact or hitting pushrod covers?

 

What's the crank runout?

 

Although the 01 bottom end should be bullet proof, did you check the crank runout then replacing the cams?
Pushrod contact with the covers could cause noise, but the vibration is caused by something else. Are all engine mounts tight?

 

I don't know current crank runout. Had the gear driven cams installed over three years ago and don't remember what it was, but mechanic checked and runout was good when the TW6g cams were installed. Never had any of this before I installed the new heads.

Maybe I did not describe the feeling correctly when I wrote engine vibrations - it's more like there is contact somewhere and constant tapping.

 

If you mean you had a lot of noise in the heads after the larger springs were installed, you may have the spring collars hitting the rocker boxes - earlier rocker boxes needed to be clearance many times for large collars.

The pushrod leak can be caused by a pushrod (usually the exhaust) hitting the inside the tube up at the head - fatter pushrods do this a lot.

If you mean the engine is physically vibrating, and the tuning is correct, keep an eye on the coil mount and fuel tank tabs for cracks. That is a sign of out of phase balancers and in the 1st 2 years of Beta engines, there were many failed balancer timing sprockets.

 

Ed,
Thanks - the sound is more a tapping contact than engine being out of balance. I guess I will start tearing bike down and see what kind of clearance I have between springs and rocker box. I have read you should be able to insert a paper clip between spring and rocker box. If I have to have a machine shop clearance the rocker box, is there a standard increase - .020, .030, ? Can you clearance too much and cause other issues?

 

I believe what Ed is referring to is contact between the valve spring retainer and the rocker box in the corner. In '05, beehive springs were introduced but unless you changed to beehive springs, you are running the double wound springs that are the same diameter bottom to top. Higher lift springs would often make contact, not with the rocker cover but with the lower rocker box in the corner when the valve are fully closed. If this is happening, you should be able to see witness marks in that corner. You can open up the contact area with a dremel tool.

 

Thanks - I do have the double wound springs, so I'll pull the covers and take a look at what is going on. Good to know I can just grind the rocker box myself - was thinking they might need to be milled. I also ordered some Rockouts to help the rocker shaft clatter while I have it opened up.