103 Upgrade Gone Wrong - Re-posted From Tech Forum
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.
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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.
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Stellar HDF Member
Joined: Sep 2007
Posts: 2,459
Likes: 674
From: Vancouver Island B.C.
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.
2. Yes. With your mileage it is definately rich. Excess fuel washes the cylinders causing ring wear = lower compression and blowby. Even though the fuel line looks ok on the dyno sheet it doesn't represent the afr anywhere else.
3. Loose pushrod would cause low compression, broken spring would cause running issues.
4. See 2.
I'll bet your oil smells like fuel. Compression and leakdown test will tell a lot. I would think that combo should be north of 100tq/90hp sae.
Ultimate HDF Member
Joined: May 2008
Posts: 7,439
Likes: 884
From: 'Noke, VA
For starters, your mechanic's claims are completely realistic. A stock 96 makes around 65 horsepower and 77 ft-lbs of torque. 50% more horsepower would be right around 98, 40% more torque would be right around 108. That's child's play to achieve with headwork. Additionally, you shouldn't take any mileage hit. I have a "B" motor 103 with a 625 cam that'll turn 45mpg all day long.
Now with all that said, something's very, very wrong with your build. Your engine shouldn't smoke, period. If it's doing that, the mechanic needs to fix it. If it's blowing oil, there's a problem, and your mechanic needs to fix it. It sounds like you're sumping, and I'd bet your cam timing is off as well. And I'd also be willing to bet your tune is no good.
Now with all that said, something's very, very wrong with your build. Your engine shouldn't smoke, period. If it's doing that, the mechanic needs to fix it. If it's blowing oil, there's a problem, and your mechanic needs to fix it. It sounds like you're sumping, and I'd bet your cam timing is off as well. And I'd also be willing to bet your tune is no good.
For starters, your mechanic's claims are completely realistic. A stock 96 makes around 65 horsepower and 77 ft-lbs of torque. 50% more horsepower would be right around 98, 40% more torque would be right around 108. That's child's play to achieve with headwork. Additionally, you shouldn't take any mileage hit. I have a "B" motor 103 with a 625 cam that'll turn 45mpg all day long.
Now with all that said, something's very, very wrong with your build. Your engine shouldn't smoke, period. If it's doing that, the mechanic needs to fix it. If it's blowing oil, there's a problem, and your mechanic needs to fix it. It sounds like you're sumping, and I'd bet your cam timing is off as well. And I'd also be willing to bet your tune is no good.
Now with all that said, something's very, very wrong with your build. Your engine shouldn't smoke, period. If it's doing that, the mechanic needs to fix it. If it's blowing oil, there's a problem, and your mechanic needs to fix it. It sounds like you're sumping, and I'd bet your cam timing is off as well. And I'd also be willing to bet your tune is no good.
Ultimate HDF Member
Joined: May 2008
Posts: 7,439
Likes: 884
From: 'Noke, VA
I mean that your combination should easily be making well over 100/100. Your map controls the overall AFR, your VE tables, and your spark tables (as well as several other parameters). I'm not familiar with the PC3, but I'm not a fan of tuners that don't utilize the O2 sensors. The dyno is simply a tool that the tuner uses to gather the data needed to create the map.
Hey guys, I'm not doing this on purpose, but everything you tell me gets me thinking about something else. One additional point, I use an LCD oil level and temperature dipstick on my bike, which since the build, has developed a leak, pushing oil into the display area of the dipstick head. Didn't matter much to me since the display stopped working some time back and I planned on replacing it anyway. Could this be because of increased pressure in the crankcase caused by a ring failure? I guess the compression check will verify that, huh? You guys are making me look at things a lot closer. Thanks, ...Don
Old story in the hot rod world "Speed cost money, how fast can you afford to go" also
"More horsepower equals less mileage"
"More horsepower equals less mileage"
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Okay, here's an update. Compression test showed 180 psi on both cylinders. Great! After riding almost 170 miles through the countryside, and a few small towns, mileage is up to 41.7 - best ever since the build...and, I pushed it some along the way
So where are we? Runs good, compression is good, over-the-road mileage is improving, and it feels like I would get higher numbers if I put it on the dyno again. Could it be that the engine was super tight and that was restraining the original dyno numbers?
Should I proceed with the bleed-down test? What will it rule out?
So where are we? Runs good, compression is good, over-the-road mileage is improving, and it feels like I would get higher numbers if I put it on the dyno again. Could it be that the engine was super tight and that was restraining the original dyno numbers?
Should I proceed with the bleed-down test? What will it rule out?
