EFI - CARB SPROCKETS
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Seasoned HDF Member
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From: (Toronto) Canada
EFI - CARB SPROCKETS
Does anyone know why a EFI bagger has a engine sprocket of 24 compared to a carb model of 25 and a clutch sprocket of 37 compared to a carb of 36? Can I change?
FYI, for anyone who does not know, a smaller sprocket at the engine means that the engine will have to revolve more times in order to turn the back wheel. A 24 takes 10.81 and a 25 takes 10.11 revs.
FYI, for anyone who does not know, a smaller sprocket at the engine means that the engine will have to revolve more times in order to turn the back wheel. A 24 takes 10.81 and a 25 takes 10.11 revs.
Road Warrior
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RE: EFI - CARB SPROCKETS
So what your saying is:
EFI 24Eng-37Clutch
CARB 25Eng-36Clutch
In theory I would think the CARB to have more bottom end, and the reason I can only speculate in that maybe it has something to do with a lag in fuel delivery, and this is used to compensate. If anyone really does know, lets have it.
EFI 24Eng-37Clutch
CARB 25Eng-36Clutch
In theory I would think the CARB to have more bottom end, and the reason I can only speculate in that maybe it has something to do with a lag in fuel delivery, and this is used to compensate. If anyone really does know, lets have it.
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From: (Toronto) Canada
RE: EFI - CARB SPROCKETS
The dealer told me that there is no reason mechanically for the sprocket change on the EFI. There is no timing or electronic reasons. He says that the efi is just more efficient in power delivery so the change was made not to lug the engine. This doesn't really make sense to me. The bike show is in Toronto this week, and I will pose the question to some other mechanics. Maybe I should just go to a six speed tranny for the extra highway speed, but since I have the primary case off now, this change is easily possible, at a much smaller cost than a six speed.
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Seasoned HDF Member
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From: (Toronto) Canada
RE: EFI - CARB SPROCKETS
ORIGINAL: pilot1996
How much of a difference do you expect in RPMs in 5th?
How much of a difference do you expect in RPMs in 5th?
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Seasoned HDF Member
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From: Texas! Ya mean there's someplace else?
RE: EFI - CARB SPROCKETS
Got your e-mail and figured I'd just answer it here.
Since you have it apart and seem to want to make the change, go ahead. You might notice the difference in acceleration, but it'd be minimal. If you do a lot of 5th gear riding, dropping the rpm by a couple hundred would probably be a good thing, if it puts you in an rpm range that results in less vibration.
Since you have it apart and seem to want to make the change, go ahead. You might notice the difference in acceleration, but it'd be minimal. If you do a lot of 5th gear riding, dropping the rpm by a couple hundred would probably be a good thing, if it puts you in an rpm range that results in less vibration.
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Road Warrior
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RE: EFI - CARB SPROCKETS
I would be interested in dropping rpm's on the top side also. I would love to have the 6speed but I feel it to be a little more than Im currently willing to pay. So by me having a carb model I could change this to a EFI model sprockets and drop top end rpm's?
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From: Texas! Ya mean there's someplace else?
RE: EFI - CARB SPROCKETS
>So by me having a carb model I could change this to a EFI model sprockets and drop top end rpm's?<
Yup. Something else that can be done is change the countershaft and/or rear wheel sprocket(s). It used to be really common on chain bikes, but isn't done as much on the belt drives. Sloptails are a real pain because not only do you have to take apart the primary, but the swingarm has to come off also. HD made two sizes in rear wheel sprockets, 65t & 70t. Good way to change a final gear ratio if your bike has a 70t. There are aftermarket sprockets available, too. J&P has a good selection of sizes, but they can be had from other sources, often for less bucks. If you've got the miles and it's time to replace the rear belt anyway, look at changing the sprockets, yoo. At any rate, if you are repalcing a worn belt inspect the sprockets closely. Once they wear through the hard anodizing, the aluminum wears very rapidly.
Yup. Something else that can be done is change the countershaft and/or rear wheel sprocket(s). It used to be really common on chain bikes, but isn't done as much on the belt drives. Sloptails are a real pain because not only do you have to take apart the primary, but the swingarm has to come off also. HD made two sizes in rear wheel sprockets, 65t & 70t. Good way to change a final gear ratio if your bike has a 70t. There are aftermarket sprockets available, too. J&P has a good selection of sizes, but they can be had from other sources, often for less bucks. If you've got the miles and it's time to replace the rear belt anyway, look at changing the sprockets, yoo. At any rate, if you are repalcing a worn belt inspect the sprockets closely. Once they wear through the hard anodizing, the aluminum wears very rapidly.