Is this a lifter issue?
Elite HDF Member
Joined: Oct 2005
Posts: 3,872
Likes: 83
From: Canton, Michigan
What year Dyna?
Is the engine 'stumble' more like a 'miss' or 'cough'? My 93 FLHS would 'cough' and 'miss' (randomly) at around a steady 70 mph when I slightly rolled the throttle on. Turned out it was the intake manifold seals leaking. Replaced all three (at the heads and the carb), and that cured it.
Another possibility is the ignition pickup going bad.
At 50k, even with stock cam (and inner bearing) and lifters, it's time to install new ones. JMO. If you choose to upgrade the cam, you can use the stock fixed pushrods with certain cams. Adjustables are convenient, but they are not without their drawbacks. An aftermarket cam will have negligible effect on you gas mileage, unless you start blasting around with the new found power. My 93 FLHS with Andrews EV27 cam, street ported heads, 'tuned' CV carb, Dyna 2000 ignition, performance air cleaner. and Thunderheader exhaust gets a reliable 39 mpg on my daily 30 miles commute (10 miles interstate, 5 miles side streets each way). I expect it would get over 40 if nothing but interstate riding at 70 mph. I'd caution you that a cam swap, will necessitate other modifications: Carb re-tune (or re-map if EFI - but your's has the CV carb), air cleaner upgrade, exhaust work. Along with the possibility of an ignition upgrade. This would be all to get the maximum benefit from the cam choice.
Personally, I'd get rid of that hypercharger, and install a Ness Big Sucker 1.
FWIW: The FSM is far and away better than any Haynes manual IMO. I'd also recommend getting a FPM (Factory Parts Manual).
Is the engine 'stumble' more like a 'miss' or 'cough'? My 93 FLHS would 'cough' and 'miss' (randomly) at around a steady 70 mph when I slightly rolled the throttle on. Turned out it was the intake manifold seals leaking. Replaced all three (at the heads and the carb), and that cured it.
Another possibility is the ignition pickup going bad.
At 50k, even with stock cam (and inner bearing) and lifters, it's time to install new ones. JMO. If you choose to upgrade the cam, you can use the stock fixed pushrods with certain cams. Adjustables are convenient, but they are not without their drawbacks. An aftermarket cam will have negligible effect on you gas mileage, unless you start blasting around with the new found power. My 93 FLHS with Andrews EV27 cam, street ported heads, 'tuned' CV carb, Dyna 2000 ignition, performance air cleaner. and Thunderheader exhaust gets a reliable 39 mpg on my daily 30 miles commute (10 miles interstate, 5 miles side streets each way). I expect it would get over 40 if nothing but interstate riding at 70 mph. I'd caution you that a cam swap, will necessitate other modifications: Carb re-tune (or re-map if EFI - but your's has the CV carb), air cleaner upgrade, exhaust work. Along with the possibility of an ignition upgrade. This would be all to get the maximum benefit from the cam choice.
Personally, I'd get rid of that hypercharger, and install a Ness Big Sucker 1.
FWIW: The FSM is far and away better than any Haynes manual IMO. I'd also recommend getting a FPM (Factory Parts Manual).
Last edited by Hackd; Jul 20, 2018 at 03:16 AM.
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Cruiser
Joined: Oct 2017
Posts: 210
Likes: 39
From: SoCal
Thats good advice, thanks guys. I don't have any particular love for the air cleaner but it isnt causing any problems and I'm short on funds for stuff that isnt broken yet. I'll swap it with a better one at some point.
My bike is a 1994, it has a screaming eagle jet kit, I believe a 180 main and 45 slow, exhaust is vance and hines short shots. I'm considering the ev27 cam too, how was it cruising on the highway at 75-80?
When the bike cuts out when I've been on the freeway it doesnt stumble or backfire, the engine just suddenly stops for half a second then comes right back on. The lights stay on. Its happened a couple times in a neighborhood in 2nd gear and while waiting at a stoplight, it sort of stumbles like it was running out ouf gas those times.
The rivets on the cam cover plates are still there, so I'm assuming the original inner cam bearing hasn't been changed yet.
My bike is a 1994, it has a screaming eagle jet kit, I believe a 180 main and 45 slow, exhaust is vance and hines short shots. I'm considering the ev27 cam too, how was it cruising on the highway at 75-80?
When the bike cuts out when I've been on the freeway it doesnt stumble or backfire, the engine just suddenly stops for half a second then comes right back on. The lights stay on. Its happened a couple times in a neighborhood in 2nd gear and while waiting at a stoplight, it sort of stumbles like it was running out ouf gas those times.
The rivets on the cam cover plates are still there, so I'm assuming the original inner cam bearing hasn't been changed yet.
Thats good advice, thanks guys. I don't have any particular love for the air cleaner but it isnt causing any problems and I'm short on funds for stuff that isnt broken yet. I'll swap it with a better one at some point.
My bike is a 1994, it has a screaming eagle jet kit, I believe a 180 main and 45 slow, exhaust is vance and hines short shots. I'm considering the ev27 cam too, how was it cruising on the highway at 75-80?
When the bike cuts out when I've been on the freeway it doesnt stumble or backfire, the engine just suddenly stops for half a second then comes right back on. The lights stay on. Its happened a couple times in a neighborhood in 2nd gear and while waiting at a stoplight, it sort of stumbles like it was running out ouf gas those times.
The rivets on the cam cover plates are still there, so I'm assuming the original inner cam bearing hasn't been changed yet.
My bike is a 1994, it has a screaming eagle jet kit, I believe a 180 main and 45 slow, exhaust is vance and hines short shots. I'm considering the ev27 cam too, how was it cruising on the highway at 75-80?
When the bike cuts out when I've been on the freeway it doesnt stumble or backfire, the engine just suddenly stops for half a second then comes right back on. The lights stay on. Its happened a couple times in a neighborhood in 2nd gear and while waiting at a stoplight, it sort of stumbles like it was running out ouf gas those times.
The rivets on the cam cover plates are still there, so I'm assuming the original inner cam bearing hasn't been changed yet.
The EV-27 seems like the standard aftermarket cam for Dyna Evos.
Listening to your video, I don't hear anything mechanical that sounds like it needs attention. I think I heard the "whine or chirping" you were talking about, and I think Dr. Hess is probably right. I think something might be rattling around in that intake. But I don't hear anything that seems like it could be related to the cutting out problem.
With the riveted on timing cover, it's almost guaranteed you still have the stock cam and stock inner cam bearing. The bearing should be swapped out now, no matter what else you do. Unless money is ultra-tight, replacing the cam while you have everything apart is a no-brainer as well. Replace the lifters (use either Johnson or S&S).
From there it depends on budget and ambition. Simplest thing is to cut the stock pushrods, leave the top end of the motor alone, and go to adjustables. Or you can pull the top end and re-use your solid pushrods (more work/less money, assuming you select a compatible cam like the EV27). Evos are always going to have some amount of valve train clatter, so I wouldn't worry about trying to dial out every last bit.
Seasoned HDF Member
Joined: Aug 2007
Posts: 8,199
Likes: 3,087
From: NW AR
When the bike is running, but cool so you don't burn yourself, grab the wire coming out of the cone down at the bottom, between the cone and the frame, and move it around/give it a little tug. If the bike dies, the wire is broke inside the insulation, which will cause the cutting out problem you describe.
Cruiser
Joined: Jul 2015
Posts: 166
Likes: 13
From: Beaufort, NC
I think the noise you are hearing, is the valve noise coming back out the intake.
If you have a screaming eagle or big sucker style backing plate and a round oiled filter with a round cover laying around... I'd toss it on and see if your noise goes away.
Did a cam swap last week and left the cover off mine, and just about shut it down instantly thinking the extra valve noise was way out of bounds... But listening to the left side of the bike all was fine. Intake noise can drive you nuts if it harmonizes.
I would swap the coil, just on principle as an overheating almost shorted coil will cut out at steady speed once up to temperature but not show any bad antics otherwise.
If you have a screaming eagle or big sucker style backing plate and a round oiled filter with a round cover laying around... I'd toss it on and see if your noise goes away.
Did a cam swap last week and left the cover off mine, and just about shut it down instantly thinking the extra valve noise was way out of bounds... But listening to the left side of the bike all was fine. Intake noise can drive you nuts if it harmonizes.
I would swap the coil, just on principle as an overheating almost shorted coil will cut out at steady speed once up to temperature but not show any bad antics otherwise.
Elite HDF Member
Joined: Oct 2005
Posts: 3,872
Likes: 83
From: Canton, Michigan
There are a number of good aftermarket cams for the EVO, and everyone has their favorites. Try to pick one that matches your riding style and your bike. You will get an increase in valve train 'noise' with most cam swaps. It's just the nature of the valve train geometry on an EVO. Some cams have a bit less, some have more.
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