Yamaha Star Stryker banner

Running lean with Cobra Fi2000. What gives?

14189 Views 58 Replies 24 Participants Last post by  rarebit
Well, guys, I put my shiny new exhaust on earlier this week and now there's trouble. A little background:

I drilled my stock exhaust a bit at first, no issues there. Then I got the Fi2000 CVT, installed that. No issues there. The old butt-dyno even told me it did some good with the low-rpm lugging through town.

Next I got the Baron's BAK put on there. That was a bit disappointing. The holes in the cover plate weren't tapped properly - I had to tap them out myself. For what that thing costs, you'd figure... well, anyway, I thought it made throttle response a bit snappier through the whole range.

Now, for the bit where it turns bad. I finally got my V&H Twin Slash Staggered pipes. In black. I put them on without any issues. They look fantastic. They sound great. But the bike's performance has gone a bit strange. It misses at odd times. Weird flat spots. If I'm accelerating hard through the gears, it's got some serious oomph and no issues. If I'm just cruising at 60 in 5th, it misfires at random.

It got really bad this morning when I was putting around in 2nd gear, 30-40mph. It was stuttering so bad I thought it was going to keel over. Quite a jerky ride. So I got home this morning and checked the spark plugs, and they're very, very white.

Obviously, I've got a problem. The question is, what else should I check before I start making angry calls to Cobra?
1 - 8 of 59 Posts
Well now I'm really confused. I pulled them out when the bike was still hot this morning and they were whiter than a sheet of paper, but after sitting all day, I have this:

Which one is the proper read :-? Sometimes I almost wish I knew what I was doing.

Thanks for the replies, guys
See less See more
Another question about the PowerPro CVT. The installation instructions say when it's working properly, the lights will behave like this: Turn the key on, it blinks "several times" then turns off. Turn the bike on, and the light comes on solid. Any blinking after that is bad.

So, mine does all this, except when it's running and I give the throttle a good twist, the light blinks off one time. Every time I twist the throttle, except if I really baby it. Is this normal?
Well, I'm puttering around double and tripple checking that I dont have any intake or exhaust leaks before I get Cobra tech support involved - I'm sure there's nothing wrong with the intake, and I haven't figured out a conclusive test for the exhuast yet... I started the bike up in the dark, no flames... there's no soot buildup anywhere... don't hear anything odd... blew some smoke around the exhaust ports and didnt see anything..

Anyhow, happened to get a good look at the pipes under the heat sheilds during all this, and holy crapola. The front header is bright blue for at least 10", and the back is blue for 2" or 3". I thought I noticed the fan running more than usual right after I put the pipes on, but I didn't think it was getting that hot...

I'm not even sure I should be riding this thing any more until I figure something out.
Just got off the phone with Phil from Cobra - with a minimum of questions, he decided it was probably a bad unit and said he was going to make a new unit for me today, test everything on it and hopefully have it shipped out to me this afternoon.


Well, I just got back into town from a work trip and my replacement Fi2000 PowerPro was waiting for me. Had it installed in a jiffy.

Out on the test ride - no difference. It's still leaning out so much it starts sputtering at the same spots. :'(

Guess I'll be on the horn with Cobra again on monday. Don't have any idea where it will go from here - this unit was supposedly hand-made and function tested for all functions personally by Phil at Cobra, so I can't very well tell them it just doesn't work.
SFCMcGan said:
That reddish around the bottom part of the plug sorta indicates the use of a fuel additive / octane booster. Are you running anything in the fuel?
SmokenJOE said:
Must be nice to be Cobra's test pilots. 8)
I'm less than enthused. I bought this thing so I wouldn't have to mess with it. Now I've been messing with it for weeks, my brand new pipes are blued all to crap, and it doesn't seem we're any closer to a solution.

edit: oh, and I'm worried about getting caught in traffic or riding on hot days because if it overheats I'm pretty sure my warranty is useless.
1 - 8 of 59 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.