rob71458· Premium Member
July of 2007 I replaced the stock camshafts in my SERK (1800 mi.) with a set from HQ. The bike ran great, 100 hp/115 tq, and I had no unusual noises. This spring (4700 mi.) I had the great idea of stepping it up a little. I purchased heads, cams, gear drive and a larger throttle body from a well known bike engine builder. I was concerned about going with the gear drive, because I had .004 run-out, but they said it would be fine. Sent the jugs out to be diamond cut and then had them lightly honed for the new set of rings. Downloaded the appropriate break in map, the engine ran good but I did have a lot of gear clatter and valve noises. I was also a little dissapointed with the performance though, seat of the pants feel just wasn't all that much better. Checked the compression after about 1000 mi. and it was down to 195 from the stock reading of 225. Tried all sorts of attempts to quiet the engine down, oversize gears, new lifters, numorous pushrod adjustment techniques, tapered pushrods, valve cover and rocker box clearancing. Spoke to Andrews Gear and they freaked me out, telling me I could have a catastrophic engine failure running gear drive with that much run-out. Decided to go back to the chain drive set up, and since the supplier could not recommend a set of cams, I tried Wood's TW-7H. Well these cams really woke up the performance, compression jumped back up to 225, but I still had excessive valve train noises. I know their cams are a little loud, but this was not normal to me. The fact that these cams were milder ( shorter duration/ less lift) than the ones in the kit, and that they helped the performance so much, I started to think that maybe the big head, big cam, big throttle body approach was not all that it was hyped up to be. I had a set of stock TC88 heads done up by HQ, went back to their cams, roller rockers. "black ops" lifters and the stock throttle body. Compression is still 225. No BS, the engine performance is superior to anything else I had tried yet, but I still have the same freakin' noise at the same engine speeds. It starts to get noisey at 1800 rpm, quiets down ever so slightly at 2000 rpm, and then comes back at any speed above that. It is a hair quieter with Torco 50, but I feel the bike performs better with the Mobil V twin 20/50. Oil pressure is fine. If I am on the highway at 3000 rpm and noisey, roll off the throttle ever so slightly to unload the engine, it will quiet down just a hair, roll back on just a hair again and it is back. Sounds like the noise is up high in both rocker boxes, on the bike it sounds the loudest from the left. Bike now has 8000 mi., this is driving me crazy. Any ideas?