255 Cam install problems
 

I just installed SE255 cams on my 09 FLHX. Got everything back together, started hard, but came on and sounded awesome except for some tapping in the rear rocker box. I know the tappets have to build up pressure, but after 30 seconds still tapping, so I shut it down. I waited 20 minutes while picking up some things, and when I tried to start it again, it starts hard. It will turn over twice, then on the third it struggles. What do I need to check?
Any help is appreciated.

Thanks.

Is this a 96" or 103". Stock compression? Reused stock lifters? No compression releases?

255's build A LOT of corrected compression due to extremely early intake close. However, I've never heard of starting as hard as you're describing on a cold engine with stock compression.


Best I can do right now is give you a bump...

iClick? You are the SE255 guru. You out there?

An obvious question but did you remap it for your new configuration?

Did you let the push rods bleed down? And if you used adjustable push rods did you set then on the base circle of the cam?

Yes, it's a stock 96", stock compression, no releases. I used a base map from Power Commanders site. I used the stock push rods, installed them on base circle and made sure the correct lengths went where they go.

tapping....sounds like you reused your old rods....did you check them to make sure they were not bent...mine were all bent after only 11K miles. Check them by rolling them on a glass top...if they wobble...they are bent...once you determine the bend curve..you can measure them with a feeler guage to confirm. Bent rods become shorter rods..shorter rods do ticky tick tick.

hard start - google checking your battery state of charge...im thinking your battery is on the light side and it was OK when your compression at start was normal...but 255's have more startup compression, so battery drain at start might be a work here.

sounds like you double checked your align ment marks for grears on the cam as well as main cam / chaft alignment. compression check with a good battery if in doubt.

you watched the cam install videos on yuotube to confirm how to make sure you are on the base circle during the install of the rockers (for non adjustable rods).

I installed the 255s on my bike and I had none of the problems you described. I used the SE adjustable pushrods and a custom map.

My bike starts a little harder but not much. It feels like the bike has a little more compression.

Re-check your installation, pushrods and map. Start with the easy stuff, like battery condition, map and pushrods.

30 seconds is not even near enough time to get the lifters pumped back up and oil to the top end. let it idle for several minutes and it will settle down when the lifters get pumped up and oil is pumped to the top. you want to hear clatter try using travel limiters it takes 20 miles for those to quiet down on initial install. oh and charge your battery.

How did you use stock pushrods without taking the rocker boxes off, or did you?

I had the SE255 cams on my 103 and it started up right away.

I am sure it might start a little "hard" if you do not have the right map in it.

Well, guru I'm not, but I'll take a crack at it. What I would check first is compression on both cylinders, which will give an indication if the cam timing is correct. It should read around 186 psi and if one cylinder is off a more than a few psi it could indicate an alignment problem. It would seem that one cylinder could be fighting the normal movement of the other as it comes into a certain alignment and cause the hesitation the OP describes.

Another thing that comes to mind is that old issue of mismarked cams. This was reported in 2007 in TT296, but I've only seen one of these reported here in that time frame (from Sickbagger). In his case compression was zero in one cylinder and the bike wouldn't even crank, so I wouldn't think this would be a prime suspect, especially since that was five years ago and you would think most of those cams are now out of circulation. OTOH if the OP bought used cams, who knows. At least one pair of those mismarked cams did work when manually aligned, so it isn't inconceivable some are still in circulation and working. Sickbagger got his running, so it is apparent there may be more out there.

CCP for a 96/255 is three psi more than stock, and corrected CR is .12 higher (Big Boyz calculator). Like you I haven't heard of anyone with a 96/255 combo complain about hard cranking, although my starter does sometimes struggle for the first rev when it starts on the compression stroke, but it isn't anything like the OP is describing.

As for the top-end noise, I would assume one lifter lost its prime and is taking a while to pump back up. I had this happen once and it clattered like a jack hammer, bad enough for me to remove all lifters and prime them. I used an oil gun and shot oil in the side hole to prime it. Sitting in oil overnight has never worked for me and I always prime them with the oil gun before re-installing.

If the pushrods were not in their proper places I think you've have some really alarming noises that would do serious damage, so I don't think this is a prime suspect either. Sometimes pushrods can hit the covers, so that's a possibility.

To the OP: Do a compression check and report back. Did you buy your cams used? CVO pull or other? Does the starter struggle like this for every start?