Before you go tearing it apart check that motor mount. You said a bolt fell out of it which got me thinking.
I had a Dyna with a worn out sagging front motor mount and after a while I would get a noise like you described. Turned out the sagging mount was letting the heat shield contact the frame near where the pipe bolts to the head.
Being you took the exhaust off recently combined with the recent motor mount trouble on your bike, there’s a possibility this is what’s happening to your bike.
Edit- just saw your post about it not running. Probably not the motor mount after all.
Last edited by Bubba Zanetti; 10-07-2023 at 04:12 PM.
Ya, initially I though it was something vibrating again something as I couldn't hear it at idle but once it became constant and I could get off the bike and listen it was pretty apparent it was internal. I am assuming with it not running I should be able to rotate the motor and see what the valves are doing and check the tension on the pushrods to hopefully tell if it's a lifter. Seems like if things are out of whack enough for it to not run it should be easy to tell if it's in the valvetrain. Hopefully the slowly dying of the motor isn't a bearing seizing up, but that seems unlikely. Signs are pointing to a bad lifter. The noise is consistent with a bad lifter. The issue initially was not constant which I feel like a bearing going would not have been so intermittent. It was doing some odd backfiring at startup. I have seen lots of posts about bad S&S lifters and they usually go out under 2000 miles, which is where mine are at now. Possibly it is just wishful thinking. We'll see. I'll pull the rockers tomorrow and have a look. The lifters are under warranty but from what I have read it will be next to impossible to actually get S&S to be helpful in any way. Probably go with fuelling lifters as a replacement if that is the issue.
Ok, so I pulled the rockers and lifters and I don't see any obvious issues. I can't depress any of them, so I bought a tool to fill and test sportster tappets. Will see what the outcome of that is when I get it in a week or so. Maybe next weekend. In the meantime let me show off the coolness of the S&S Rocker boxes. You can remove the rockers without removing the base of the rocker box so there are no gaskets to replace unless you need to pull the heads. The removable parts to get the rockers and pushrods out all use o-rings and rubber seals.
Pretty sweet. A steal at only $1100, not really. I scored a new set from a guy on eBay with new S&S rockers, new shafts, and all the gaskets and hardware for $450. I guess his project went south. That would have run about $1500 retail.
Last edited by OCSpringer; 10-08-2023 at 08:28 PM.
Well after all I saw yesterday I feel like the issue is in fact the bottom end. I will test the lifters to do my due diligence but they seem fully pumped up and OK on inspection. I really don't see anything suspect on the top end and I am fairly confident the noise was coming from the area of the crank when I was listening. Oh, the irony. Got the rest of the bike completely done, 2k miles after the top end, and the bottom end goes an hour into the maiden voyage. Well at least everything else on the motor is new, so when I get the bottom end done I don't have to buy anything else and the top end is already just broken in.
Just got off the phone with Dan from Hammer performance and we talked through what I have done thus far, what was done to the bike and next steps as well as costs to do the bottom end. This is going to be pretty involved so I may just start a new thread and document everything for those who want to know what to look for when tearing down the engine to see if the bottom end is going or if the issue lies elsewhere. As of now most signs point to the bottom end but there are a few other things it could be as well such as a bent valve, sheared pinion shaft key, a cam issue, and lifters are still a possible cause. I drained the oil and don't see any metal in the oil. I will cut open the filter but from the looks of it so far I think it will be fine. I just read through a whole thread from a guy who had the same problem, and he thought it was the lifters so he replaced them and put everything back together only to have the same issue and it turned out to be a bad crank bearing. I want to avoid having to do all this twice so I will check the lifter when i get this tool and if they are good, which i suspect they are, will pull the cam cover and pull the cams and check the pinion and oil pump drive gears. Then I'll pull the primary and check that there is nothing going on in there before pulling the heads, cylinders, and pistons to check for play in the rods.
Last edited by OCSpringer; 10-09-2023 at 01:13 PM.
Got the tappet tool today so I can test them out this weekend. I suspect they will be fine. I'll finish tearing down the motor on Saturday and hopefully something stands out. So far everything looks good, but still have to pull the primary, heads, and cylinders before I can get at the rods.
Pretty neat tool.
Last edited by OCSpringer; 10-19-2023 at 11:14 PM.
Ok, so now I need a little advice. I pulled the primary cover today and there was definitely some contact with the stator rotor and likely the Hayden primary chain tensioner.
The question is, is it possible the corner of the chain tensioner would be hitting the exact same spot over and over? I guess it is possible if the runout on the crank shaft is such that it was just barely hitting at the point of greatest runout.
So now I have a conundrum. Do I pop the stock tensioner back in and put it all back together and hope that was the issue or do I keep digging down to the rods to be sure?
It's not that simple unfortunately as the motor is already half torn down, so there is some cost to put it back together and fire it up. I personally think this is not the issue I am after but it is still an issue. I am going to finish tearing it down and check the rods regardless I think. I have already found a couple issues to address so I might as well finish tearing it down so I know exactly where I stand. At this point I think I am just going to rebuild the bottom end regardless. I should have done it when I replaced everything else 2000 miles ago.
10-07-2023, 04:10 PM
