Tunning help needed, 750 gsxr cams

[Sharp Shooter]

Proud owner 93 Katana 750.
Running a V&H SSR2 full exhaust system a Factory Pro stage 3 jet kit & K&N air filter. Dyno was 100 hp last season and she ran great.
Dropped in a new set set of GsxR 750 cams and she ran even better, however needed tunned in a bit.

Ok, so I took her back to local shop that installed the jet kit & dyno tunned her last season and here's the big issue. Got her back and runs like Sh%t !!! around 93 hp w/a giant hole in my mid-range!

Starts and runs great until gets to 6-7+ grand, missing and surging sounds really fat, add some throttle and the r's drop baddly, but once she pulls out and above 8 grand or so she comes back to life. The shop can't get the bad spot out infact it's way worse than it was before I took her in to get dyno tunned.
The shop said they dropped the needles all the way down took out plastic spacers on the needles played w/air fuel and basically gave up!! Really need tunning advice.
CP.. someone anyone please!

[ThAzKat]

SERIOUSLY,go back to your stock jets and needles!!!!
set the a/f screws at 2.5 turns out!
I have a 93 with the S1 slingshot motor from factory that way. I have 110's in #1, #2 and #4 and a 112.5 in #3, no flat spots thru the whole rpm range. I have stock needles with no shims. floats are at 14mm. a/f's are at 2.5. If you do gixer cams on my engine, bad idea unless you degree them.

[yngveny]

A lot of people here would tell you to loose the K&N's and go back to stock airbox and filter.

Could be a good place to start..

That been said I am in no way an expert in these matters.....

[Court93kat]

I have done the cam swap same as you. Here is an issue I ran into after double checking my work. I needed to triple check apparently. Make sure that one of the cams are not ONE tooth off from each other and they are perfectly lined up with each other. It caused some really funky symptoms with my bike until I went back and fixed that.

[Sharp Shooter]

She ran great just a small flat spot @4500 or so and a small spot at 6500. nothing major just a little hesation. Ran her 200 miles after cam swap, Rechecked cams and they are dead on the marks, adjusted valves a hair and all good, sound great w/no adnormal valve noise. then took 2 shop to get dyno done.

[GregS]

Did they do an initial dyno run? What was the baseline HP and torque?
You said it ran good when you brought it in and what they did was lean it out by dropping the needles. That implies it is too lean in the range of the flat spot.
What throttle opening is the flat spot at? They may have done all the "tuning" for full throttle at the expense of part throttle. So it may be way too lean at that RPM and part throttle so that it makes best power wide open.

[ThAzKat]

I am more interested in the ega chart. Lets see the dyno chart of your run before cams!

[Sharp Shooter]

pre cam swap dyno

[Sharp Shooter]

shop didn't give new dyno run sheet said would... but did'nt. I think they did'nt want me 2 see it till after I paid them the 160.00 bucks I just paid 4 nothing.
I pick her up last night, just before they closed. Rode home 15 miles or so as it started to rain... so no real test ride! Need 2 get 2 work so i wil check back soon.
p.s. thanks guys I really look forward to your help and reply's.

[GregS]

Now compare that to the initial run with the cams and then the final run.
Also as pointed out it would be good to see the A/F ratios and the throttle openings at which they took the readings.
For a good explanation of CV carb tuning, go to Factory Pro's website. In the Tech Support section you'll find CV carb tuning. Look under the High RPM section. It is surprising how close you'll get the tuning using these "seat of the pants" instructions.

[ThAzKat]

ok, tuning tip that many of us tech's use. tape on throttle with idle, 1/4 turn, 1/2 turn, 3/4 turn and wot marks. that way you can establish exactly in that range your stumble or flat spot is!

[Sharp Shooter]

I used my stock cam chain sprokets w/new gsxr 750 cams. I read this was a drop in deal w/pre98? How do you index the cams?

[ThAzKat]

I used my stock cam chain sprokets w/new gsxr 750 cams. I read this was a drop in deal w/pre98? How do you index the cams?

You must give me my bike back!

Cam gears have to be slotted for degreeing. about 3 degrees I believe but I can stand corrected on that!

[Sharp Shooter]

LoL sounds like yours may be running better than mine right now, so mabey u have mine!

[ThAzKat]

well you are one step ahead of me, I haven't dyno'd mine since 2003 and it was just after I got it and it was untouched. After sitting for a few months and not carb cleaning or anything else I ran a 97 hp at sea level in AZ! Now that it is a bit tuned and exhaust I believe I have reached what you can do without opening the internals!