103 Upgrade Gone Wrong - Re-posted From Tech Forum
Posting the dyno sheet might reveal something.
A proper compression and leakdown check is necessary to help eliminate possible problem areas. You need to know where your compression is. I'd be looking at cam timing, re-checking pushrod adjustment, checking to make sure the intake manifold went back on correctly. If the compression checks out, I'd start taking the top end back down and checking for problems.
A proper compression and leakdown check is necessary to help eliminate possible problem areas. You need to know where your compression is. I'd be looking at cam timing, re-checking pushrod adjustment, checking to make sure the intake manifold went back on correctly. If the compression checks out, I'd start taking the top end back down and checking for problems.
Stellar HDF Member
Joined: Dec 2009
Posts: 2,561
Likes: 280
From: North Cental Iowa
Mileage also depends on engine efficiency, I have a 103 with 10-1 comp, P&P heads, .570 lift cam, 240- 248 duration & I regularly get between 42-50 mpg. Last year at Sturgis my buddy with a stock 08 96" averaged 3-4 less mpg than me. It takes X # of HP to move a bike at any given speed, if that HP is achieved with less stress & pull on the engine you will get better mileage. Sounds to me like the tune is off, the A/F ratio can be spot on, but if the timing is off, too low, the bike will run like crap & get lousy mileage. Too bad you had to learn the hard way, a reputable shop is usually worth the extra $$.
Stellar HDF Member
Joined: Oct 2007
Posts: 2,950
Likes: 234
From: Kentucky
Let me ask the question right up front. What could be wrong with my upgrade?
The guy who wrenches my bike talked me into a 103 upgrade when I went to him for just a cam change. His promise? Increase in the power band, a 50% increase in HP and 40% in torque, all without any real change in mileage. The cylinders and heads were sent for the rework and damaged in shipment. Although the damage was supposedly done during shipment to the shop, the shop replaced them with "fresh pulls" because the damage was not reported in time to make a valid shipping insurance claim. The cylinder was bored and the heads ported. New cams, gaskets, and pistons accompanied the modified heads and cylinders, then re-installed.
Right away I noticed a positive change in the torque range from the cam upgrade (what I asked for to begin with); however, the power was just not there and the mileage sucked royally (as low as 29 mpg vs. the 44 I was getting). My problem is that a post break-in dyno revealed numbers in the stock range w/stage I changes - 74 max hp and 79 torque. If I really baby the ride by not getting over 3,000 rpm or above 55 mph, I can get 37 mpg on a 150 mile ride.
I knew there was a problem when I took the bike back to have a compression and bleed down test done. The mech (I don't consider him a full blown mechanic now, so I just refer to him as "mech") had to borrow a compression gauge and the fitting was the wrong size (automotive vs HD). He could not do the compression test and I'm not sure what he planned for the bleed down. He checked the cam timing which looked okay. The mech wants me to take the bike by another shop to have the tests done at my expense. I don't plan to do that. As a matter of fact, if the mech does not step up to the plate to fix this problem, then I'm probably going to another mechanic and then to small claims court to get back some of what I'm out.
All I want is for my bike to perform at or near expectations. My question is what could be wrong with the upgrade that lends itself to what I described above?
The guy who wrenches my bike talked me into a 103 upgrade when I went to him for just a cam change. His promise? Increase in the power band, a 50% increase in HP and 40% in torque, all without any real change in mileage. The cylinders and heads were sent for the rework and damaged in shipment. Although the damage was supposedly done during shipment to the shop, the shop replaced them with "fresh pulls" because the damage was not reported in time to make a valid shipping insurance claim. The cylinder was bored and the heads ported. New cams, gaskets, and pistons accompanied the modified heads and cylinders, then re-installed.
Right away I noticed a positive change in the torque range from the cam upgrade (what I asked for to begin with); however, the power was just not there and the mileage sucked royally (as low as 29 mpg vs. the 44 I was getting). My problem is that a post break-in dyno revealed numbers in the stock range w/stage I changes - 74 max hp and 79 torque. If I really baby the ride by not getting over 3,000 rpm or above 55 mph, I can get 37 mpg on a 150 mile ride.
I knew there was a problem when I took the bike back to have a compression and bleed down test done. The mech (I don't consider him a full blown mechanic now, so I just refer to him as "mech") had to borrow a compression gauge and the fitting was the wrong size (automotive vs HD). He could not do the compression test and I'm not sure what he planned for the bleed down. He checked the cam timing which looked okay. The mech wants me to take the bike by another shop to have the tests done at my expense. I don't plan to do that. As a matter of fact, if the mech does not step up to the plate to fix this problem, then I'm probably going to another mechanic and then to small claims court to get back some of what I'm out.
All I want is for my bike to perform at or near expectations. My question is what could be wrong with the upgrade that lends itself to what I described above?
Sorry to hear about the problem, that's rough. Hope you get it all worked out and get the power you should have. This is one of the reasons I'm letting the dealer where I bought my bike do mine. It may cost a little more but they are doing this on bikes every week and I trust their experience. There is no reputable indys in my area, at least in my opinion.
Stellar HDF Member
Joined: Aug 2008
Posts: 2,404
Likes: 11
From: Southern Nevada (Pahrump)
That sucks! Find a reputable builder with a dyno. If the mechanical build tests ok a good tune should be achievable & you'll be happy with better performance & fuel mileage than your currently seeing.
Outstanding HDF Member
Joined: Feb 2007
Posts: 2,710
Likes: 6
From: Spokane, WA.
Sorry to hear about the build not coming out and running as hoped for. It sucks when in good faith a person puts out some hard earned bucks has an expectation from an indy, that hopefully has a reliable rep, and you only get half of the smile per mile factor.
I had a few items that with my 103 build on my 07 flstf, that if I had it to over again- I would have changed some things.... i no longer have the bike.
Hope you are able to get issues resolved.
I had a few items that with my 103 build on my 07 flstf, that if I had it to over again- I would have changed some things.... i no longer have the bike.
Hope you are able to get issues resolved.
Cruiser
Joined: Mar 2011
Posts: 210
Likes: 6
From: N/A
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Dyno sheet is posted and my son-in-law is reminding me of more details, so here goes.
1. Pipes should not be a big issue; however, I'm running true duals with SE stock slip-ons (that came off a SE getting aftermarket slip-ons).
2. I'm running a PC III USB w/o O2 sensors. Could this be a limiting factor? If so, why?
3. I have a loud tapping noise on the top end that the mech said is not unusual. I'm/we're wondering if a broken valve spring or out of adjustment push rod could play a role.
4. I never see this because I'm on top of the bike, but my son-in-law has told me several times that smoke comes out of the exhaust when I'm pulling off. This may be that it is running rich at idle.
Commentary: The cam seems like it is doing what it is supposed to do because of the curve characteristics, so maybe the problem is in fuel delivery or compression loss.
1. Pipes should not be a big issue; however, I'm running true duals with SE stock slip-ons (that came off a SE getting aftermarket slip-ons).
2. I'm running a PC III USB w/o O2 sensors. Could this be a limiting factor? If so, why?
3. I have a loud tapping noise on the top end that the mech said is not unusual. I'm/we're wondering if a broken valve spring or out of adjustment push rod could play a role.
4. I never see this because I'm on top of the bike, but my son-in-law has told me several times that smoke comes out of the exhaust when I'm pulling off. This may be that it is running rich at idle.
Commentary: The cam seems like it is doing what it is supposed to do because of the curve characteristics, so maybe the problem is in fuel delivery or compression loss.
Cruiser
Joined: Mar 2011
Posts: 210
Likes: 6
From: N/A
Got start with the basics. Need to know what they set the head volume at what head gasket was used & what the deck height was along with what pistons flat tops or domes.
Then ye need to check the CCP & also follow up with the leak down test.
Was that dyno performed when the build was new?
Then ye need to check the CCP & also follow up with the leak down test.
Was that dyno performed when the build was new?