Feels like clutch slipping...

[TileGuy]

I've put a little over 500 miles on my 08' STT since I got it a few weeks ago. So far I'm pretty happy with the bike but I have a couple concerns. I was riding it yesterday and had two instances where I was accelerating out of a right hand turn in second gear and it felt like the clutch was slipping. I got on the throttle and the engine sounded like it was increasing rpm's but the bike didn't accelerate accordingly. It was only for a second or so each time so I didn't really have a chance to watch the tach and see if it was really revving or just sounded like it. I tried a few times to accelerate hard and drop the clutch hard and could not get it to slip. Maybe just the heat causing some hesitation in the engine? The bike has under 7k miles so I can't imagine the clutch is shot. I am going to do a clutch adjustment and change the oil as soon as I get a chance. Just wondering if there is anything else I should look for or if this is just another one of the Buell "quirks".

My other concern is the erratic idle at startup and general inconsistency of power. When I bought the bike he told me that it had always stalled at first startup. It will fire and run for a few seconds then stall. After that you start again and it stays running. After I got it I changed to NGK Iridium plugs, did the breather mod, and modded my exhaust. For a while after the plug swap the startup problem was gone. Now it is back, occasionally, along with a surging idle and sometimes stalling before it warms up. It really runs like crap until fully warmed up which I think is a typical Buell trait. I have done a TPS reset a couple times with no change. I wondered about dirty injectors since the PO only rode it twice last year and not at all this year. It just seems to be so random. Some times I hop on and it runs great and feels really strong. Other times it feels like power is really lacking. I really thought going to a fuel injected bike it would run a lot more consistently than it does. When I get more time/money I plan to try datalogging and tuning but in the mean time is this typical to Buells or should I be looking for something?

Thanks,
-Sean-

 

[go cytocis]

I agree it's tough to imagine a burned out clutch after only 7000 miles, unless the PO really abused it. Try an adjustment if you haven't already.

The cold stalling sounds like an electronic engine management issue to me. I recall others with a similar problem. I am sure someone will respond with the answer you are looking for. In the meantime try searching on here for it.

 

[Jmal18]

Gumout fuel system cleaner and then tune.

Here's a link that might be helpful when you're ready to tune.

Xopti

 

[sicsteeth]

Just tinker around with the cable adjustment, links on utube. Really easy

 

[TileGuy]

I took it out today and it happened again. This time I gave it more throttle and it definitely wasn't slipping. There is a certain range in the throttle where the engine sounds like it's trying to rev, but power isn't there. If I give it enough throttle it springs back to life. Really weird. Must be fuel or tuning related, right? I'm going to adjust clutch and change oil anyways. I need to get it hooked up to a computer.

 

[user_deleted]

on your clutch...do the simple things first as i doubt it needs replaced. replace the primary fluid with 1 quart of a quality oil such as 20-50 amsoil motorcycle oil, castrol act-evo, silkolene red, Bel-Ray #80 gearsaver. any of them are top quality. the drain plug is o-ringed and on bottom of primary. let it drain several hours if you can. you can refill either thru derby cover or chain inspection cover.
adjust clutch cable and lever as per service manual. if you don't know how post back and i'll be happy to walk you thru it. very simple procedure.
for what it's worth i have 4 buell xb's and they all need a bit of "throttle help" at cold start to stay idling until sufficiently warmed up. lastly, your ecm unit is under your seat. are the connections tight and does the unit itself look pristine? no cracks, gouges or other cosmetic signs of a problem?

 

[TileGuy]

I adjusted the clutch and changed the oil. The clutch feels better. Still have the dead spot in acceleration. I figure it's tuning related. Changed my exhaust a little and that seemed to help, but only slightly.

Another thing I'm curious about is the breather mod. I did it as soon as I got the bike. I T'd the two breathers together, ran the line back under the seat, T'd it again to a breather filter under the seat and a leg running down behind the footpeg. I have put several hundred miles on with nothing accumulating in the line. Is this strange?

 

[Simple Guy]

Tuning is everything on the new bikes the hesitation that you are felling when you ride could be a air stall the flow is kinda siting still and the fuel is still coming in so the bike is flooding itself or the complete opposite and the air is good and there is not enough fuel there for it either way a good tuner should be able to fix that. for the cool start and stalling same thing there needs to be tuned for the idle rpm's.

 

[user_deleted]

Another thing I'm curious about is the breather mod. I did it as soon as I got the bike. I T'd the two breathers together, ran the line back under the seat, T'd it again to a breather filter under the seat and a leg running down behind the footpeg. I have put several hundred miles on with nothing accumulating in the line. Is this strange?

no. as it should be.

 

[TileGuy]

This thread title doesn't really apply any more but i'm going to keep this all under one thread.

The bike is still not running well. I'm becoming more and more disappointed the more I ride it. Its a shame because I think its a really cool bike. The power just isn't there. I knew going into this bike that I wasn't going to be "wowed" by the power. But from spending countless hours reading through forums I feel like mine must be way underpowered right now. Sometimes I will hit the throttle and it will feel great. Other times it falls flat on its face. I'm still leaning towards tuning issues, but I build engines, I don't tune them. That area is completely new to me. I have read the threads and walkthroughs and I feel I'm capable, I just have to get the software and do it. For my 08' I need ECMSpy "mono" correct? I couldn't find where to actually donate and download it. I have a friend with the cable so I'm set there.

The dead spot around 3k is what really bothers me. It is sometimes lower rpm's too. I have searched around and found thinks like intake leaks that I need to check for. I had some misconception that a fuel injected bike should perform pretty well right out of the box. Sounds like its good for some and not for others.

Anyways I pulled the plugs again to check them. There is some soot built up on the bottom of the threads, but the insulators look pretty white. Front has some color. I'm used to seeing the brown color on a good running engine.

Rear Cylinder:

Front Cylinder:

Sorry for the crappy cell phone pics. Wires look good too. It would appear I have the leaky rocker boxes, or at least the rear. Also looks like oil coming out around the breathers. More crappy cell pics:

Also here is my breather mod setup. I don't see any reason why it shouldn't work this way. If I'm wrong please tell me why.

I love this bike and I love riding. Its just not quite what it should be. With only 7k miles I was hoping I had some time before the problems started. Luckily I can fix anything. Buell's are new to me though so there's a learning curve. Thanks again for all the help guys!

-Sean-

 

[user_deleted]

are they NGK DCPR9EIX plugs sean? front appears to be excessively high heat range and leanness.

 

[go cytocis]

The dead spot around 3k is what really bothers me....I had some misconception that a fuel injected bike should perform pretty well right out of the box.

I am certainly not dismissing the potential that you have a real problem that needs to be corrected, but the XBs do have a well-documented issue with FI hesitation & stumbles below ~4000 rpm. It's especially pronounced if you have experience on other nicely-mapped I-4 FI bikes.

The tuners of the stock map would have had a very challenging time trying to meet EPA emissions AND getting this old Harley lump to make decent power at the same time. It's no surprise to me that smoothness got compromised. Having said that, the later models, like your 08, are generally better mapped so you shouldn't be having serious rideability issues.

In my case with my 06 Ss, I wouldn't have called the stock map "unrideable", but it was surely disappointing! I found that the EBR race ECM greatly transformed the smoothness & power right across the rev range and almost completely eliminated any low rpm stumbles.

 

[TileGuy]

are they NGK DCPR9EIX plugs sean?

Yes, found them as recommended on this form.

 

[TileGuy]

I just found and burned new fuel maps. They are 06 race maps modified for 08's. I'm going to try it out and see if that helps. Then I will try to datalog and tune further. I have been doing tons of reading and rereading about tuning. I get the jist of it, but I'm not quite ready to dive in yet.

 

[Simple Guy]

Plugs look very lean to me. Will add on the Harley twin cams there Ecm's use the plugs as the Knock sensor and have heard that you shouldn't change from the stock plugs not sure if Buell is the same or not. Anyone care to share on that so that I may know??