SuperMoto Junkie banner

1 - 7 of 7 Posts

·
Registered
Joined
·
29 Posts
Discussion Starter · #1 ·
Bike info: 2008 SM610 that I purchased ~2 months ago with about 6600 miles. Currently it has about 7400. It has a LV slip-on with the "Power Up" kit.

I did some work on the bike last night, and took it out for a jaunt afterwards, and now it's running different. The first thing I noticed is that the idle speed was different. I usually leave the idle adjuster alone and just crack the throttle when turning it over, then hold it around 2000 for a few seconds. My first thought was that this was just the idle speed cable having been moved around, as it's pretty sensitive (idle raises slightly if bars are turned to the left and the cable tightens :rolleyes:). That still may be the case there.

One of the few things that bugged me about the bike (initially, until I got used to it) was how it was somewhat like a 2-stroke--at low RPM (less than maybe 4500ish) it was either on or off, there was an extremely small range of neutral throttle. I learned to find that 'barely cracked open' spot instinctively, and last night noticed that this was significantly reduced. It was just enough that it struck me as odd as I pulled out of the neighborhood. I did notice it again as I came back into the neighborhood. (I try to keep it quiet near home :D)

Then I got to really riding it. It seems like a lot of the mid-range punch where it feels strongest is missing. Power-wise it doesn't feel like something is terribly wrong, but more like I imagine a stock bike being before a slip-on/PU (haven't ridden one, I'm just guessing there). I also noticed that it was popping on decel a bit. I know this is common (with the carbed bikes at least), but before last night, I had never once heard it do so. Literally, never, and then last night it did it several times. Not huge backfires or anything, just the normal popping sound. Lastly it died/came-very-close-to-dying-before-I-saved-it several times when pulling up to stop lights. Again, I've never had anything like that happen. The only time it's ever shut off without the key/killswitch was when I killed it at a light my first time riding it, which was all me.

As for what I actually did to it, there were a couple of things (of course!).

The PO had checked the valves not too long before I bought it, though I don't recall the exact mileage. I wanted to go ahead and do it myself for peace of mind, so I did. I thought that they sounded a bit loud (though that sounds like it's normal for these motors), and found that they were all a bit loose, ranging from maybe .003"-.005" (the exhaust a bit larger that the intake it seemed). Being loose seemed odd, but maybe they were just set more conservatively? Better loose than tight I suppose. I'm worried that I may have set them too tight, though I set them all to where I could get the .003" feeler in there, but not too easily, and the .002" went in without much trouble beyond the difficulty of working in such a tight space. I also checked them at both TDC and IN as EX was opening, EX while IN was closing.

Now there were a few other things. One, I put the fan back on. The PO had removed it, as he said that even out in Borrego (hot desert) it never came on. I believe I noticed that it had 4 wires where I would expect 2, there's not an air temp sensor or something else in there? I didn't really look, I just noticed the 4 wires and it occurred to me after finding that it ran odd.

Another thing... the "PU Kit" was a DIY resistor, attached using butt connectors to the pigtail cut off of the O2 sensor. It hung down where the O2 used to be and bugged me, so while I had the tank off I was moving it around to tuck it up out of the way and pulled the resistor out of one of the butt connectors. Instead of putting another crimp joint on, I soldered that end and put heat shrink tubing over the whole deal. I left the crimp joint on the other side.

So, things I'm thinking that have changed that could be the culprit. (why does it always happen when you change multiple things?)

Fan? I can try unplugging it, but I doubt that's it. Of course I tucked the plug up under the tank, so it would have to come off.

PU/O2 sensor plug? I would think that if I lost connection there, or burned up the resistor soldering, or otherwise botched it, that I would have the neutral light flashing telling me that something is wrong. I would also think that if it wasn't making connection before that I would've had a code. I'm assuming that just unplugging the O2 completely throws a code, but you know what they say about assuming. I didn't think to check the resistance, either by the color code or with a multimeter, but I could certainly unplug it and check the resistance (2.2k) at the pigtail to ensure that the connection is good. That also means the tank has to come back off--maybe I should've left it hanging down...

Valves too tight? It's not the first time I've adjusted valves, though admittedly usually on cars where it's far easier to get to with the feeler gauge, but it's not my first time doing a bike either. I could certainly loosen them up a bit and see if it changes. I don't exactly want to, but just because it's a PITA, not because it would be difficult. I did notice that the feeler would bind, but then when I'd get it to the right angle, it would slide around with a slight drag like I'm used to; I think that's just because of the tight confines and short bend radius of the tiny feeler gauge (motion pro style) if it wasn't completely perpendicular to the valve stem axis. Again, I figured if I could just get the .003" in there with some significant bind it was good.

Lastly, to position the motor I was turning the rear wheel in 6th gear, and I did turn it backwards a bit. It's not like a was sitting there spinning it backwards, just back and forth to get it where I wanted, like finding the very top of TDC. With the ratchet on the ACCT, I can't imagine that the chain could've slacked and timing jumped a tooth or anything crazy like that, but I thought I'd mention it so that others can assure me I'm not a complete idiot.

On a related note, the PO said that he had checked the CCT recently and it was at 6 clicks. I'm going to check it tonight. I understand that you pull the center bolt first to relieve the spring tension so that it doesn't just extend as you pull it out. How do you count the clicks? I seem to recall reading debate over whether it's teeth showing, or teeth showing + 2?, as counted from the ratchet pivot point? The manual does seem to show the pivot point, though I haven't pulled it out yet, so I'm sort of flying blind.

Thanks for any help you can offer! Sorry for the long post.

-Kris
 

·
Registered
Joined
·
102 Posts
it honesly sounds like your moto needs a tune up. valves out of spec would be a big concern. you could seriously damage your bike. i say just tune it up.
 

·
Registered
Joined
·
29 Posts
Discussion Starter · #3 ·
it honesly sounds like your moto needs a tune up. valves out of spec would be a big concern. you could seriously damage your bike. i say just tune it up.
? I thought that's what I was doing... What do you 'tune up' on a FI bike? Adjust the valves--engine-wise that's the only thing I can think of besides standard maintenance stuff like filters and fluids. Maybe change the plug, but it looks good and I didn't change it so that can't be why it's running differently. I certainly don't want to change anything else right now until I figure out what already changed.

I have a feeling that it's something with the fuel injection just based on the way that the throttle reacts differently. I had wondered previously if it was perhaps the TPS idle value in the computer needing to be reset. I also know that choppy throttles at low RPM is just something that goes with big thumpers, and performance motors in general, so I didn't pay it much attention. That's one of the areas where fuel injection is supposed to be superior over carbs, but then the injection on bikes seems to be a bit behind the tech in comparison to cars.

Normally as valves wear they get tighter, so being on the loose side makes me think that the PO just set the gap a little wide. Neither is great for it long term, but they weren't that loose, and I'm sure that if I did get them a little too tight that they're not that tight. If someone really thinks that may be the issue then I can try setting them a little wider, but riding it down the road for a test ride isn't going to instantly burn up a valve.
 

·
Registered
Joined
·
29 Posts
Discussion Starter · #4 ·
So I looked at the fan last night and I must've been remembering the plug for the O2, since the fan is just a power and ground like I would expect, so that's definitely not it.

I pulled the "PU plug" and checked the resistance, and it's 2.2k ohm, so that's fine. Just turning the key on with it unplugged throws a code and the neutral light flashes; plugged it back in and cycled the key and it went away, so I'm going to assume that it had good contact in the past, so that hasn't changed.

Looking at how much the idle speed cable moves around, I would say that could definitely explain the difference in idle, as I had to adjust it again after pulling the tank off again.

I checked all of the valves again, and they're all .002", maybe .003" (if you get the angle of the 3 thou feeler just right it'll slide around, but otherwise hangs up a bit.) I would still say that they're tighter than they used to be, they were more like .005" before. I could see someone setting them there thinking that they were correct, as right now you have to get the feeler just right for them to slide around, a little larger and they move around with a little drag pretty easily until you get the angle right, then they feel loose. At this point that's the only thing that seems to have changed. I guess I could try setting them loose, back to where they started and see what happens.

After riding it again, it seems that I might've been tricking myself into some of my observations. The low rpm throttle 'smoothness' may have just been placebo. It still seems a little different, but could definitely be in my head. The same may go for power delivery, but I'm not sure on that one. It doesn't seem as strong, but now I'm doubting myself, wondering if I've just gotten used to the power over the last month, and am just now noticing it because I'm looking for something. The popping, however, is new, which it's still doing, though maybe not quite as much as the first night. It still wanted to die on me a bit, but again, not as much. The decel popping and idle issues sure make it seem like it's not all in my head.

On another note, I attached a picture of my ACCT. I believe that it would be counted as 7 clicks? The first notch visible is really the first, there aren't any hidden behind the aluminum plunger, so there are 7 notches exposed/it's moved out 7 clicks from full in. I'm going to go ahead and order the stuff needed so I have it on hand. Did anyone ever try that Tsubaki chain from a GSXR-1100? It looks like there were a couple of folks who were going to try it, then nothing...
 

Attachments

·
Registered
Joined
·
102 Posts
well i do know that husky has come out with an updated wiring harness. it fixed the dying at idel for me.
 

·
Registered
Joined
·
29 Posts
Discussion Starter · #6 ·
well i do know that husky has come out with an updated wiring harness. it fixed the dying at idel for me.
Interesting. I wonder if I might've tweaked something in the harness in the process of R&Ring the tank. I haven't heard about this, any info/threads on it? I'm going to do some searching right now. :hmmm:
 

·
Registered
Joined
·
102 Posts
no i just found out when my bike randomly started dying at stop lights. i took it in n they told me it was a new set up. n they wernt lying the part number wasnt the same
 
1 - 7 of 7 Posts
Top