OFFICIAL SITE - Quick Throttle® Magazine - Northwest Edition: Ask Arlin

Fuel Injection Dilemma
Q: Arlin, I picked up a copy of Quick Throttle and read your column. I appreciate the information you’re willing to put into print. Most of the shops clam up when I ask a “how-to-fix-it” question. I can’t blame them, I know that’s the way they get work. But I’m one of those guys that likes to work on my own bike. With all the technology these days, that’s not always possible, but I’m hoping I can get enough information to make any repairs needed.

My bike is a 2005 FLH with just over 15,000 miles on it. It started running poorly this past summer. The bike wants to jerk and miss at part throttle. I’ve been over the intake and exhaust connections, looking for air leaks, but found none. There are no codes showing, and I followed the manual for checking codes without a scanner. I’ve also been talking with our local dealer here in BC. They’re just telling me they would need to check it out at their shop before giving any advice. Have you run into this problem? If so, can you give me a hint of what to look for? — Mark & Cindy, Penticton, BC

A: Mark, I’ve run into the same thing more than a few times. I can’t guarantee my advice will solve your problem, but it will give you a few more things to check out.

When we get a problem like yours in the shop, the first thing I do is go over all the connections. Take your time and pull each sensor connector apart and check for corrosion or loose or bent pins. If they look OK, get some dielectric grease and coat the connectors before putting them back together.

Take a good look at your spark plug wires and connectors. These are cheap to replace. If you do replace them, you will get rid of the possibility that they’re faulty. You didn’t say if you had a Power Commander or some other type of controller. If you can unplug it, try it without it hooked up to see if the problem still exists. I’ve seen a few controllers with connectors that have loose pins. This can cause intermittent problems. Be sure your battery is in prefect condition. A weak battery can cause a weak signal.

If the problem still exists, I usually go straight to the CP sensor. It’s located in the left front of your motor, with an allen head bolt holding it in. The newer models have a connector under the voltage regulator. For me, this has been the number one sensor for causing problems like you’re having. The good news is, it’s easy to replace and not very expensive. Like I said, I can’t guarantee the results, but these checks have worked for me. Good luck with it. Please let me know if you find the problem.

2007 Road King Tracking
Q: Why doesn’t my bike track straight? I end up sitting and leaning to the right side of my bike to keep it going straight. The bike is brand new with less than 5,000 miles. I was told at the shop where I bought it that the bars are installed wrong. It seems like more is wrong than the bars. Have you seen this kind of problem on any other bikes? —Joe, Tacoma, WA

A: Yes. I’ve seen this problem more than once on both new and old bikes. The first time was with a wrecked bike I bought to fix up. It looked OK when I bought it, but when I got it home and started looking at it from the back, I could see the bike wasn’t sitting straight. When I sat on it the rear wheel was leaning to one side. A friend of mine, a long-time Harley technician, took me to a dealership to show me other bikes with the same problem. Even new ones! I was totally surprised as I’m sure some of you are after reading this. You mean new bikes can come from the factory wrong?!?

Well, let’s just say they can come from the factory out of adjustment. After putting Joe’s bike on the lift and doing an alignment procedure, the bike still leaned to one side. Following is what I learned to do from my friend. It’s not in the service manual and shouldn’t be considered a final fix, but it will get you sitting straight with the road:

First, you’ll need to prop the bike up so the front wheel is perfectly straight up and down. This should only be done after you’ve gone through the alignment procedure outlined in your service manual. Using a jack, get the bike to a straight position. You can measure this by using a magnetic level on one of your front disks. Once the bike is stationary and sitting straight up, go to the rear of the bike and stick the level on the rear disk. If your bike is out of alignment, it will show on the level. Be sure you check your set-up several times before making any adjustments.

Once you’re sure it’s off in the front, find the top stabilizer bolt and strut. It’s under the tank on the left side and ties the top of the motor to the frame. When you tighten or loosen the strut, it tilts the motor right or left. Since the motor and transmission are connected to the swing arm through rubber washers and bushings, this adjustment will twist the motor right or left—whichever way is needed to get the motor straight with the rear wheel. The rubber washers in the ends of the swing arm may be mismatched or one of them may be defective. Something is causing one of the sides to sag, dropping one side of the swing arm, causing the bike to lean to one side. It’s a good idea to check the swing arm washers as well as the bushings inside of the arm. If any of these are damaged, it will allow the bike to sag to one side.

The manual says the strut bolt in the top motor mount, should drop in with no tension on it, once it’s adjusted. In this example, we’re using the strut to pull the drive train straight. That’s why you need to examine the rubber parts holding the swing arm in place. Be sure to take a good look at your shocks. If one spring is weaker than the other, this would cause the same off-center lean or sag. We got Joe’s bike 98% straight, so Joe can sit in the middle of the seat now and the bike goes straight when you let off the bars. I don’t think of this kind of problem as a poor quality thing. It’s just a fine tuning adjustment.

Q: Arlin, I just bought my second Harley. It’s an almost-new 2007 Fat Boy. The guy that had it installed a set of Vance & Hine exhaust, a Screamin’ Eagle air cleaner and a closed-loop fuel injection controller. The bike runs OK, but still pops when decelerating, and surges at cruise speed. My question is, will a Dyno tune and remap help the popping and surge? — Marcie, Boise, ID

A: Marcie, you need to have your bike looked over for air leaks. You could have one in the intake, or, more than likely, the exhaust. Both will cause both problems. The whole idea of the closed-loop system is for the wide band sensors to control everything. Some of these units claim their sensors will make data changes up to 500 times per second. As long as these sensors are working, they’re making their own map—at least that’s what they claim. If your air leaks are bad enough, the oxygen sensors won’t be able to adjust the injection enough to take care of the problem. If your controller has a record feature, you should be able to go for a ride and record the problem. Then you can see it on a chart.

A Dyno session will give you the same kind of information, only in real time, using a different oxygen sensor. I think if you get the air leaks handled, your problems will be over. Follow the manufacturer’s instructions for setting up the controller and your bike should perform like it was designed to. Enjoy your new ride!

Arlin Harmon, Owner
Full Throttle Cycle Performance
5212-A Washington Street, Tacoma, WA
253.472.7633
info@v-twinperformance.net


QUICK THROTTLE® MAGAZINE - NORTHWEST EDITION Your Free Local Monthly Motorcycle Magazine!
NATIONAL HOME ABOUT US ARCHIVES BIKER FRIENDLY BIKER GALLERY BIKER NEWS EDITORIAL OUR ADVERTISERS RIDE & EVENTS CALENDAR ADVERTISING INFO H-D's FOR SALE LINK TO US SUBSCRIBE	Fuel Injection Dilemma Q: Arlin, I picked up a copy of Quick Throttle and read your column. I appreciate the information you’re willing to put into print. Most of the shops clam up when I ask a “how-to-fix-it” question. I can’t blame them, I know that’s the way they get work. But I’m one of those guys that likes to work on my own bike. With all the technology these days, that’s not always possible, but I’m hoping I can get enough information to make any repairs needed. My bike is a 2005 FLH with just over 15,000 miles on it. It started running poorly this past summer. The bike wants to jerk and miss at part throttle. I’ve been over the intake and exhaust connections, looking for air leaks, but found none. There are no codes showing, and I followed the manual for checking codes without a scanner. I’ve also been talking with our local dealer here in BC. They’re just telling me they would need to check it out at their shop before giving any advice. Have you run into this problem? If so, can you give me a hint of what to look for? — Mark & Cindy, Penticton, BC A: Mark, I’ve run into the same thing more than a few times. I can’t guarantee my advice will solve your problem, but it will give you a few more things to check out. When we get a problem like yours in the shop, the first thing I do is go over all the connections. Take your time and pull each sensor connector apart and check for corrosion or loose or bent pins. If they look OK, get some dielectric grease and coat the connectors before putting them back together. Take a good look at your spark plug wires and connectors. These are cheap to replace. If you do replace them, you will get rid of the possibility that they’re faulty. You didn’t say if you had a Power Commander or some other type of controller. If you can unplug it, try it without it hooked up to see if the problem still exists. I’ve seen a few controllers with connectors that have loose pins. This can cause intermittent problems. Be sure your battery is in prefect condition. A weak battery can cause a weak signal. If the problem still exists, I usually go straight to the CP sensor. It’s located in the left front of your motor, with an allen head bolt holding it in. The newer models have a connector under the voltage regulator. For me, this has been the number one sensor for causing problems like you’re having. The good news is, it’s easy to replace and not very expensive. Like I said, I can’t guarantee the results, but these checks have worked for me. Good luck with it. Please let me know if you find the problem. 2007 Road King Tracking Q: Why doesn’t my bike track straight? I end up sitting and leaning to the right side of my bike to keep it going straight. The bike is brand new with less than 5,000 miles. I was told at the shop where I bought it that the bars are installed wrong. It seems like more is wrong than the bars. Have you seen this kind of problem on any other bikes? —Joe, Tacoma, WA A: Yes. I’ve seen this problem more than once on both new and old bikes. The first time was with a wrecked bike I bought to fix up. It looked OK when I bought it, but when I got it home and started looking at it from the back, I could see the bike wasn’t sitting straight. When I sat on it the rear wheel was leaning to one side. A friend of mine, a long-time Harley technician, took me to a dealership to show me other bikes with the same problem. Even new ones! I was totally surprised as I’m sure some of you are after reading this. You mean new bikes can come from the factory wrong?!? Well, let’s just say they can come from the factory out of adjustment. After putting Joe’s bike on the lift and doing an alignment procedure, the bike still leaned to one side. Following is what I learned to do from my friend. It’s not in the service manual and shouldn’t be considered a final fix, but it will get you sitting straight with the road: First, you’ll need to prop the bike up so the front wheel is perfectly straight up and down. This should only be done after you’ve gone through the alignment procedure outlined in your service manual. Using a jack, get the bike to a straight position. You can measure this by using a magnetic level on one of your front disks. Once the bike is stationary and sitting straight up, go to the rear of the bike and stick the level on the rear disk. If your bike is out of alignment, it will show on the level. Be sure you check your set-up several times before making any adjustments. Once you’re sure it’s off in the front, find the top stabilizer bolt and strut. It’s under the tank on the left side and ties the top of the motor to the frame. When you tighten or loosen the strut, it tilts the motor right or left. Since the motor and transmission are connected to the swing arm through rubber washers and bushings, this adjustment will twist the motor right or left—whichever way is needed to get the motor straight with the rear wheel. The rubber washers in the ends of the swing arm may be mismatched or one of them may be defective. Something is causing one of the sides to sag, dropping one side of the swing arm, causing the bike to lean to one side. It’s a good idea to check the swing arm washers as well as the bushings inside of the arm. If any of these are damaged, it will allow the bike to sag to one side. The manual says the strut bolt in the top motor mount, should drop in with no tension on it, once it’s adjusted. In this example, we’re using the strut to pull the drive train straight. That’s why you need to examine the rubber parts holding the swing arm in place. Be sure to take a good look at your shocks. If one spring is weaker than the other, this would cause the same off-center lean or sag. We got Joe’s bike 98% straight, so Joe can sit in the middle of the seat now and the bike goes straight when you let off the bars. I don’t think of this kind of problem as a poor quality thing. It’s just a fine tuning adjustment. Q: Arlin, I just bought my second Harley. It’s an almost-new 2007 Fat Boy. The guy that had it installed a set of Vance & Hine exhaust, a Screamin’ Eagle air cleaner and a closed-loop fuel injection controller. The bike runs OK, but still pops when decelerating, and surges at cruise speed. My question is, will a Dyno tune and remap help the popping and surge? — Marcie, Boise, ID A: Marcie, you need to have your bike looked over for air leaks. You could have one in the intake, or, more than likely, the exhaust. Both will cause both problems. The whole idea of the closed-loop system is for the wide band sensors to control everything. Some of these units claim their sensors will make data changes up to 500 times per second. As long as these sensors are working, they’re making their own map—at least that’s what they claim. If your air leaks are bad enough, the oxygen sensors won’t be able to adjust the injection enough to take care of the problem. If your controller has a record feature, you should be able to go for a ride and record the problem. Then you can see it on a chart. A Dyno session will give you the same kind of information, only in real time, using a different oxygen sensor. I think if you get the air leaks handled, your problems will be over. Follow the manufacturer’s instructions for setting up the controller and your bike should perform like it was designed to. Enjoy your new ride! Arlin Harmon, Owner Full Throttle Cycle Performance 5212-A Washington Street, Tacoma, WA 253.472.7633 info@v-twinperformance.net
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