Odd problem with a 84 sportster xl1000

[kurtis84]

I've had this bike a couple years now, and it seems to run strong. A while back, I had a car run me off the road. After chasing that person down, this bike has developed a very annoying problem. ( yes I know I shouldn't run an iron head hard ). The exaust brace on the rear end actually cracked in half from the high rpm's I was turning. After welding that back together, I noticed now that if I run for a few minutes at around 70mph, the engine just falls on it's face. I've replaced every electronic component this bike has on it trying to fix this, and it still does it. All I have to do is try to pass a car, and I'm reminded this problem is still there.

The engine actually sounds like a valve is stuck, but it clears up after I slow back down. I can run the bike to around 8000rpm's between gears, but can't run over 3500-4000 for more than a few minutes. I've had the heads down to the block to fix a leaky gasket, and see nothing wrong. I've adjusted my lifters a few times to see if thats the problem ( it's not floating the valves as far as I can tell ).

Please anyone with some insight on this help me out, at this point I'm willing to try about anything.

[HDMD88]

Originally Posted by kurtis84

I've had this bike a couple years now, and it seems to run strong. A while back, I had a car run me off the road. After chasing that person down, this bike has developed a very annoying problem. ( yes I know I shouldn't run an iron head hard ). The exaust brace on the rear end actually cracked in half from the high rpm's I was turning. After welding that back together, I noticed now that if I run for a few minutes at around 70mph, the engine just falls on it's face. I've replaced every electronic component this bike has on it trying to fix this, and it still does it. All I have to do is try to pass a car, and I'm reminded this problem is still there.

The engine actually sounds like a valve is stuck, but it clears up after I slow back down. I can run the bike to around 8000rpm's between gears, but can't run over 3500-4000 for more than a few minutes. I've had the heads down to the block to fix a leaky gasket, and see nothing wrong. I've adjusted my lifters a few times to see if thats the problem ( it's not floating the valves as far as I can tell ).

Please anyone with some insight on this help me out, at this point I'm willing to try about anything.

Interresting....I think I would check the valve springs next, it's possible that the inter spring is broken or as far as that goes the outer spring could be broken. The springs could be weak not letting the engine to rev high. Check it out....or replace all the springs...they are fairly cheep. Good Luck You didn't by chance put those can opener baffles in your drag pipes did you? if so they won;t let your engine rev either...

[kurtis84]

Valve springs. That makes plenty sense. I guess I didn't consider it since I was just in there, and everything appeared ok. I know looks can be deceiving in such a matter though. I just wish I didn't have to tear down the heads again, as it's very tough to get the rocker assembly off with the engine on the frame.

Oh well, sounds like a reason to stay in the garage for a day haha.
Thanks for the help.

[HDMD88]

Originally Posted by kurtis84

Valve springs. That makes plenty sense. I guess I didn't consider it since I was just in there, and everything appeared ok. I know looks can be deceiving in such a matter though. I just wish I didn't have to tear down the heads again, as it's very tough to get the rocker assembly off with the engine on the frame.

Oh well, sounds like a reason to stay in the garage for a day haha.
Thanks for the help.

My Pleasure Kurtis.....If you don't have access to a spring tester just by all new springs, there cheap.
Good Luck