AIS to the Rescue (AGAIN)

Come and listen to my story about a man named Jed . . . no, wait, wrong story . . .sorry (and appologies to Flatt - or maybe Scruggs).

This story is about how glad I am that I have a functioning AIS system on my RSV.

My bike has been running perfectly, no popping or anything else odd, but when I had it all torn down last Saturday to check the valves, I thought it was a perfect time to go ahead and replace the plugs anyway. It was a little early for me with only about 15,000 miles on them, but I had the old ones out, so why not? Well, on the 200+ mile ride home from Tom's place, I was getting a lot of loud popping and bangs rolling through the small towns. Bummer!

You can probably imagine how disappointed this made me - here I had just done major work on the bike and put in new plugs and all - I expected to be getting about 150 miles to the gallon and roll through town to cheering crowds! But alas, instead of basking in the adoration of pretty women and admiration from all the wannabe bikers, I found myself having to hide my face in shame.

Now the odd thing is, I didn't notice anything else wrong with the bike - gas mileage might have been down just a tad, but considering the 105 degree heat and high speeds I was running, it wasn't really lower than normal. And I had zero problems hitting an indicated 100 MPH passing a couple of long strings of cars, so all four jugs had to be hitting OK, right? But there is no denying the evidence - popping from the exhaust on these bikes absolutely proves something is wrong with the way the fuel is burning.

So today I finally drug my rear out to the garage to check things out. I fired the bike up and began checking how fast the header pipes were heating up with my fingertips, and it was obvious that the RF (#4) pipe was different. The other three were too hot to keep my finger on for more than a second or two within 15 seconds of starting the bike, but not #4. It was fairly warm, but not burning. Even tho these were brand new plugs, I pulled it and put an old one in - problem solved!

And THAT's why I am so tickled my AIS is working - without the warning signs from the exhaust popping, I would have almost certainly ridden the bike with that bad plug in there for 20,000 miles or so before I accidentally fixed it during the next major service. The interesting thing is that this was the EXACT same symptom Ponch had with his bike up at Don's maintenance day - same cylinder, same symptoms, same fix. And his only real indication that something was wrong was the popping when he tried to reconect his AIS system!

Goose

Come and listen to my story about a man named Jed . . . no, wait, wrong story . . .sorry (and appologies to Flatt - or maybe Scruggs).

 

This story is about how glad I am that I have a functioning AIS system on my RSV.

 

My bike has been running perfectly, no popping or anything else odd, but when I had it all torn down last Saturday to check the valves, I thought it was a perfect time to go ahead and replace the plugs anyway. It was a little early for me with only about 15,000 miles on them, but I had the old ones out, so why not? Well, on the 200+ mile ride home from Tom's place, I was getting a lot of loud popping and bangs rolling through the small towns. Bummer!

 

You can probably imagine how disappointed this made me - here I had just done major work on the bike and put in new plugs and all - I expected to be getting about 150 miles to the gallon and roll through town to cheering crowds! But alas, instead of basking in the adoration of pretty women and admiration from all the wannabe bikers, I found myself having to hide my face in shame.

 

Now the odd thing is, I didn't notice anything else wrong with the bike - gas mileage might have been down just a tad, but considering the 105 degree heat and high speeds I was running, it wasn't really lower than normal. And I had zero problems hitting an indicated 100 MPH passing a couple of long strings of cars, so all four jugs had to be hitting OK, right? But there is no denying the evidence - popping from the exhaust on these bikes absolutely proves something is wrong with the way the fuel is burning.

 

So today I finally drug my rear out to the garage to check things out. I fired the bike up and began checking how fast the header pipes were heating up with my fingertips, and it was obvious that the RF (#4) pipe was different. The other three were too hot to keep my finger on for more than a second or two within 15 seconds of starting the bike, but not #4. It was fairly warm, but not burning. Even tho these were brand new plugs, I pulled it and put an old one in - problem solved!

 

And THAT's why I am so tickled my AIS is working - without the warning signs from the exhaust popping, I would have almost certainly ridden the bike with that bad plug in there for 20,000 miles or so before I accidentally fixed it during the next major service. The interesting thing is that this was the EXACT same symptom Ponch had with his bike up at Don's maintenance day - same cylinder, same symptoms, same fix. And his only real indication that something was wrong was the popping when he tried to reconect his AIS system!

Goose

And That my Friend is why I was LISTENING to you as you spoke to me about that very same thing! I may kid ya at times but definitely know when to shutup and listen. Tom

Glad you figured it out Goose. So you had a (bad) new plug.. Mmmm, I put a new set in a 90 Horse Mercury outboard one time, wich was a in line six cylinder. The plugs where what was reccomended from factory and what was in the motor to start with(NGK). I was doing a service and thought this would also be good to replace plugs also. The motor never ran right after that.

Well to make a longer story short, I ended up taking it to a dealer and the problem was that one of the new plugs was boken inside the class of the plug. You could actually pull the tip and the long inside steel shank right out of the plug. The motor would run ok idling and then go down the lake and misfire. You could see the burnt markings on the piece of shank. I probably still have that plug. I had a mind to send it to NGK and tell them they owed me $100.00 for all my trouble and the expense.

But I never did. Glad you got her fixed Goose, I new when I started reading that you would figure it out.

James

So, Goose, are you planning another maintenance day down there? I'd love to come down and let you impart some knowledge on me in terms of carbs and the whole AIS system. Although, come to think of it, my bike probably needs more work than could be done in a maintenance day setting.

My problem is, I'm a visual person. You can tell me, or I can read, how to do something but I can't visualize it. If I can see it done it sticks and then I can do it fine after that. I know, I'm weird.

So, Goose, are you planning another maintenance day down there? I'd love to come down and let you impart some knowledge on me in terms of carbs and the whole AIS system. Although, come to think of it, my bike probably needs more work than could be done in a maintenance day setting.

 

My problem is, I'm a visual person. You can tell me, or I can read, how to do something but I can't visualize it. If I can see it done it sticks and then I can do it fine after that. I know, I'm weird.

My personal opinion is to get a bike, no more than 2 and help but watch at the same time.We had 4 bikes tore down and for me it was Overwhelming to say the least. Even though with the tools I think I can do it I will feel more comfortable watching and helping one more time with only 1,maybe 2 bikes tore down. A knowledgeable wrencher could probably tear his down at the same time and learn as he is watching.

Oh I'm all about the helping and learning. To me, learning by doing is the best possible way to learn. Thanks for the advice on a lower number of bikes for this type of job. I agree that keeping the number of bikes down helps, that's why I cast doubts on a "Maintenance day" setting for working on my bike .

So, Goose, are you planning another maintenance day down there? I'd love to come down and let you impart some knowledge on me in terms of carbs and the whole AIS system. Although, come to think of it, my bike probably needs more work than could be done in a maintenance day setting.

 

My problem is, I'm a visual person. You can tell me, or I can read, how to do something but I can't visualize it. If I can see it done it sticks and then I can do it fine after that. I know, I'm weird.

I have resisted the idea of calling for a real maintenance day here simply because I don't have the room in this neighborhood to have 10-20 bikes squeezed in. Seems to me that 5 or 6 is about the number I'd be comfortable with at the house.

But I have repeatedly told people I was available for help - even tried to organize a carb clinic here once. If you want to ride on down, that's great. Let's set a date and see who else wants to show up too. I've already got someone coming up from Houston to do carbs on the 25th - is that too soon for you?

Goose

Unfortunately, yeah, that is too soon, I think. I'll think about it and see if I can jostle some things around but I don't think it's feasible.

Question. How would a person know, from feeling the exhaust, if the problem was the plugs or if the A/F mix was off in that (those) cylinders or if the sync was off etc. By that method I noticed that my rear cylinders were too hot to keep my finger on but both of the fronts were hot but not as hot as the rear two.

Question. How would a person know, from feeling the exhaust, if the problem was the plugs or if the A/F mix was off in that (those) cylinders or if the sync was off etc. By that method I noticed that my rear cylinders were too hot to keep my finger on but both of the fronts were hot but not as hot as the rear two.

Feeling the header pipes is just one indicator of an issue, and the best way is to touch them as close to the exhaust port as possible immediately after the engine is started cold. This is because even a partially firing cylinder will get too hot to diagnose pretty quick, and a cold start is when the bike might have the biggest problem firing cleanly. But you have a VERY short window before the pipes get too hot up there (must always be testing the inside pipe, not the chrome cover). Then you can try touching them further down - the front pipes are easy to access by the floor boards, and you probably have a couple of minutes for a good comparison between them at that point.

But to your actual questions - no way to tell just from the heat what is causing the poor combustion, but typically if just one pipe is much cooler than the others it will be an ignition problem from coil or plugs. At least that is a good place to start.

As for the difference between the back and front pipes - I don't have a good explanation for that, but it has not been uncommon. One thing is that the rear header pipes are much shorter, and they will pick up heat from both ends (front exhaust gas blowing by). Even when the bike is fully warmed up, I get lower temps from an IR thermometer on the front clamps than I do on the rear two. I petty much figured that was caused by different angle and less access for the thermometer, but maybe it is a design thing? But for the fingertip test, the fronts should still be getting too hot to handle about as fast as the rear ones.

Goose

Another way to see if your hitting on all 4 cylinders is to find a mechanic who has a non-contact IR thermometer and shoot all 4 pipes...

Goose, so when I was having a bad #3 Coil on the rear and did that

same pipe check. is it cuz the coil was warmed you enough yet?

Just wondering. ?? hardly had any spark going to that plug. however

I did have my AIS removed. (all pipes warmed up even)

Thanks,

Jeff

If your pipes warmed up evenly on startup, then your coil was working fine when it was cold. It is not uncommon to have a coil break down under heat and fail then. But remember, the heat test is only good within the first few minutes after starting the engine cold - after it has been running a while, heat will seep through everything and even out.

Goose

Gatcha, thanks goose

If your pipes warmed up evenly on startup, then your coil was working fine when it was cold. It is not uncommon to have a coil break down under heat and fail then. But remember, the heat test is only good within the first few minutes after starting the engine cold - after it has been running a while, heat will seep through everything and even out.

Goose

Many thanks for this explanation Goose.. a local RSV rider was going to be removing his AIS (even though there wasn't any blurpling noises coming from his pipes) as he always removed his AIS from his other bikes (VStar).. I mentioned this article to him and now he's decided to leave everything as is.. just in case, ya never know..

I'll be checking my exhaust ports today when I cold start the bike.. just for the ****z and giggles.. ya never know!

Cheers M8

Hey Goose. Any idea what temp the exhaust will run at when warmed up? Looking to get a IR Thermometer.What temp do I need?

Hey Goose. Any idea what temp the exhaust will run at when warmed up? Looking to get a IR Thermometer.What temp do I need?

It is over 400 degrees, IIRC - I've checked it that way before, but you really don't get decent readings to compare, and it will be impossible without a laser dot to allow precise aiming. I found the the temperatures vary by huge amounts just by moving the dot only 1/4 inch. The most reliable reading is directly off the header clamp, not on the pipe.

Goose

Range of themometer would need to go how high to handle everything would need to be 500? 600? Have seen several. Higher they read more they cost?? This would be my main use for it. To read exhaust pipes but want to read cold engine up to operating tempts.