Master Of Pain Posted April 17, 2006 Share Posted April 17, 2006 I had a dyno performed recently on my 97 at Honda of Houston. I trust their calibrations - they are the most reputable dealer and service department in this city, and anything I've brought to them in the past is pretty well dead-on for the most part. The full size is here: HTTP://COLLINSNETWORKS.DYNDNS.ORG/COLLINSN...yno_4_15_06.jpg Look at that AFR! How shitty is that? I have a K&N / Factory Jet / Full Yoshi combo on the bike that I didn't install. Any suggestions on main jet sizes/pilot/needle placement would be helpful. This bike is way down on power! Four pulls, everything basically the same. How's that for consistency? Quote Link to comment Share on other sites More sharing options...
shovelstrokeed Posted April 18, 2006 Share Posted April 18, 2006 Well, if you manage to flip that A/F ratio chart left to right you'll be a lot closer. Damn, the thing is lean on the top end and over rich in the lower to mid range. Hopefully, you'll be able to tune that out. Going to the Yosh is probably going to lean out the top end even more so maybe up 2 sizes from standard on the mains. I would start with the needles one notch down from center and then your gonna probably have to play with the idle air a bit. Not sure I wouldn't put a smaller pilot jet in there depending on what it meters in the 'birds carbs. You for sure need to lean out that bottom end. On an EFI bike this would be a simple fix, on carbs, it is really gonna take some extra work. It appears to me that the diaphragms (I assume CV carbs here) are pulling the slides up too soon which would explain the sag in the torque due to the over rich condition in that 4K range. Of course, this is all armchair stuff. I haven't been into a 'bird airbox never mind the carbs. I'm an EFI guy for good. Quote Link to comment Share on other sites More sharing options...
Justin Posted April 18, 2006 Share Posted April 18, 2006 Need someone with experience to tune the jets on the carb .. like he said above, its all wrong .. you should be able to get a bit more if its setup right Quote Link to comment Share on other sites More sharing options...
Master Of Pain Posted April 18, 2006 Author Share Posted April 18, 2006 I purchased the bike used in Apr 05. It already had the K&N, full Yoshi and a Factory sticker on the airbox. It is quite possible that the installer scammed the previous owner to an extent. When I opened the carbs a few weeks ago to clean them, I saw the hex bolts on the bowls and Ti multi-position needles, so I assumed the Factory Ti Jet kit was installed. I also saw 2 holes on the slides, but I have no clue as to whether they are drilled out or not. Perhaps someone could comment on the slides? So, what's the optimal AFR curve for a carbed bike? I researched this topic and all I found was the FI suggestion - start at 13.2 and end up at 12.8. Quote Link to comment Share on other sites More sharing options...
shovelstrokeed Posted April 18, 2006 Share Posted April 18, 2006 A/F ratio is A/F ratio, doesn't matter what the metering system is. Mid range, full throttle will best be served at around 13.2:1, top end power will be best at around 12.6:1 but should not get that rich till the motor is near max power output. Assuming all the stuff was installed, I'd go up one size on the main jets and drop the needle a notch. You won't hurt anything doing that and it should, at least, flatten out that A/F curve. This is very much a cut and try process unless you have a ton of experience with a particular combination. Could get spendy in terms of dyno time. Quote Link to comment Share on other sites More sharing options...
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