Some of you may be following my build in the Evo section. Long story short, 106" Evo (S&S case, Darkhorse crank rebuild, Axtell cylinders, domed pistons, worked heads, etc...) Recently I got it running, then due to a lean condition smoked the front cylinder.

Back on the road (substantially richer) and over 100 miles so far and I'm noticing a knock/tap SOMETIMES... Like rolling around city streets, there will be a pronounced tappet knocking definitely coming from the right side. Then it'll fade away. It's definitely lifters because it follows RPM's but at a slower rate, and I can hear exactly where it's originating. Then some other times I'll get a knock from the left side. Sounds like a cylinder/piston slap but the fact that it comes and goes it throwing me off. The last piston slap I had would show itself just off idle at light acceleration, and initially as I accelerate at lower speeds, and was repeatable. This is not repeatable, it will be happening one minute, gone the next. Louder when lightly accelerating BUT very heavy throttle and everything sounds great! Also, highway speeds don't seem to be as pronounced but I can't really tell with the wind noise. I can hear a random rattle somewhere on the highway but it's more rare than the knocking. Sounds like a heat shield but none are installed.

Like last night, I did my 50 mile oil change and went back out to put more miles on cruising the highways around Miramar in the slow lane. Fire the bike up, no knocking. Head down the road, tappet knocking. Hit the gas a bit, no knocking and great pull. Constant throttle, tappet knocking and light cylinder knocking. After that I was on the highway for a while and couldn't hear much. Then back on the city streets, same thing. Pulled up to the house and at idle everything magically stopped and it sounded great!

WTF?!?!?!?!? I'm gonna go buy a stethoscope today to do some more sleuthing. Yesterday I cleaned the tapped passage screen and added preload to the pushrods up to a total of .125". I'm wondering if my:

primary chain too loose
fancy harmonic balancer in place of compensator is taking a **** and causing weird noises
cheap Chinese lifters should have been S&S instead

 

Or are all Evo's just noisy and when you modify them they get noisier?

I just got back from a little shakedown and same thing. Using the stethoscope I did hear some occasional tapping out of the front cylinder, more than likely the excessive piston clearance from the blow up. I measured the clearance and it's about 4.5 thou on the front, 4 on the rear.

Damn tappets kept making intermittent noise too. I may crank down the preload to solid lifter range just to see if it's them or not.

 

If in fact an imported lifter was used, I suspect that could be it, losing pressure occasionally.
Scott

 

Thanks Scott.

I did some digging into the cheap-*** lifters (CAL) and compared them to the Jims Big Axle ones that came out of the engine (with the shot rollers on the two exhaust valves). Use this pic for reference:



On two of the CAL's the oil metering plate was actually stuck in the plunger piston. I had to remove the check valve assembly and use a small screwdriver to hammer it out. Once out they were clearly marred and worn where they touch the plunger piston. On the Jims, those just fell out along with the pushrod seat. Under the micrometer, they were clearly too large so I swapped them out with the ones out of the Jim's lifters. FYI, the Jims metering plate was the same size as the metering plates in the CAL's that weren't stuck.

Also, I couldn't find the check valve spring on one of the four CAL's so Jims donated that as well.

Now I have four, hopefully servicable lifters, but they're going in a bag for future Evo use. I also ordered a set of Hylift Johnson Slow Leak lifters, should have by Friday. I also need some new lifter block gaskets.

 

just out of curiosity, what is your intake set up? a/c and carb, or injected with an a/c?
m

 

HSR42 with forcewinder style air cleaner. Why?

 

the mikuni slide an rattle around, and if you've never heard it or are not familiar wtth the sound/noise it makes it can drive you nuts the first time you run into it. i don't know if you've ever heard it before, but it my be something to think about.
m

 

Good to know, thanks. I've heard it before on my Dad's Dyna, which has the HSR and I believe lost the little round gasket that's supposed to keep the slide in place a bit better because I can really hear that thing rattling around.

 

Cam ?,
Whos lifters?
what is your oil P.?

 

S&S 585
Chinese/eBay CAL (cheap-*** lifters), which as of today will be swapped out for Hylift Johnson slow leak lifters I got in yesterday
S&S HVHP