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**SlytlyDeranged** · 03-28-2005, 01:49 AM

If it was a full V&H it was probably rejetted to stage one. Cyber Poet had a stock jet kit on ebay. Not sure if it sold or not, you should pm him and ask. Would be willing to bet Special K has some stock jets. Why would you take off the V&H and go back to stock????

**md86** · 03-28-2005, 02:03 AM

You should try to find out WHERE it's running rich . If it's just down low , you can adjust that easy enough with a screwdriver . Midrange , even easier to adjust . All ove , maybe try different jets . That's the thing about jet kits and pipes and stuff , you gotta "tune" them .

**89katana750** · 03-28-2005, 01:00 PM

I changed back to stock because the guy I bought it off decided to saw off the canister and put some $40 replacement on it. He thought it was too loud so thats why he did that... it didn't get much quiter IMHO. I've been basically rebuilding the bike back to stock for almost a year now, this is the last thing i have to do. Can't wait to bring it out on the road!

How did I adjust the fuel/air mixture then?

**89katana750** · 03-28-2005, 01:02 PM

It looks exactly like
<---------- my avitar
<----------
<----------

**SlytlyDeranged** · 03-28-2005, 01:32 PM

Good looking bike. I am going to leave this one to the experts. Cyber, Thaz, where are youuuuuuu?????

**ThAzKat** · 03-28-2005, 01:51 PM

Uni's are no good with stock system in my opinion.
Everyone goes to the aftermarket exhuast for performance, why would you want to go back to stock?
General rule on jetting is 2 # sizes and then go from there. Ivan is the one that coulc give you the jetting that is best for that setup. SS could mean Stainless Steel, Super Sport, Stage 2, I would guess stage 2 is in it if he had a aftermarket pipe and stock air box, stage 3 with pods.

**89katana750** · 03-28-2005, 02:23 PM

Im going back to stock so my bike reliability is better

I've never seen a stage 2 kit for the pre98 kats before. only 1 and 3.

**The CyberPoet** · 03-28-2005, 06:13 PM

I think I've covered parts of this before:

(A) I have no clue what the cams are doing to the intake and exhaust times, because I'm not sure how they compare to the Kat cams. The normal GSXR engine for your time-frame has a longer stroke and a narrower bore, so I would suspect that means the valves stay open longer, but don't know for sure.

(B) The best way to return to reliability is to go back to a "known good" solution, and the factory set-up as the bike originally shipped is the best "known good solution" on the planet -- especially if you bought the bike without the current mods on them (and thus don't know exactly what to do with it).

(C) Ivan's probably not going to help you unless you buy one of his kits -- he makes a living selling them, and he'll support you if you buy one, but not under other circumstances normally.

(D) Running rich causes several problems, the biggest of which is carbon build-up. This will foul plugs in the short run, but will also cause carbon build-up in the cylinders over a longer period of time, which can lead to a large variety of problems, including serious engine damages. Carbon is harder than steel, so for example, if enough of it builds up on the face of the cylinder to hit the valve as it opens, the valve can get bent. Carbon can also hold heat, so it can start triggering misfires once it gets hot enough to ignite the inbound mixture before the spark plug goes off. Finally, carbon displaces volume, and that change in volume can increase the compression rate to the point of compress-based combustion, which would cause both severe knocking and dieseling (with likely resultant damages to the various bearings among other parts).

(E) If you know the mix is running too rich, the question becomes where is running too rich -- at idle, in the mid-range, at top end, or all-over?

If you're getting after-pops on decelleration blowing out the exhaust, it's not too rich at idle, but too lean. For that, turn the pilot screws up a 1/4 turn at a pop until it doesn't do this any more.

If you're getting poor performance at high RPM's (and resultant clogging), go down on your jets by 2.5 to 5 sizes at a time (i.e. - if you have 120 mains, install 115's or 117.5's and retest).

(F) Get rid of the UNI Filter. Put the stock filter back in there. This will reduce the speed of the inbound charge (which may richen the mix more), but it will filter air a ton better and get you closer to being back to stock. If you don't know where you're running too rich, get an exhaust gas analyzer (Gunson, check ebay), or a get a garage to check it with theirs (most car garages have them and will let you test for $5 - $15 if you ask nicely) -- then figure out which RPM's you're lean, you're rich, etc, and get back to me. Remember to test only after the engine is warm.

Q: Why did you put in the GSXR 750 cams, or did a previous owner? Do you still have the old cams?

Oh, and for the record, the bike ships with what could be considered a stage zero jetkit -- a stage 1 is not the same the OEM jetting & needles.

Cheers
=-= The CyberPoet

**ThAzKat** · 03-28-2005, 09:33 PM

I wonder if you have Gixxer carbs also, you should check the carb #, I think Cyber might have the stock Kat #'s

**89katana750** · 03-28-2005, 10:35 PM

The guy who first owned the bike put on the V&H SS full exhaust with the GSXR Cams/rockers and stage 1 jets, the guy before me decided to saw off just before the canister and attach some "cherry bomb" muffler. Thats when I got it. (stock gearing also 15/47)

I rode it for the summer and I tested once how fast it went and it showed 230km/h or 145mph and it probably could have gone slightly faster but barely (its probably off by 5-10km/h). My low end was what the problem was for me. 2000rpm-3500rpm was not smooth, but then above it moved very quickly smoothly and obnoxiously loud (cherry bomb muffler).

So I rode back 5000km home and was annoyed by the loudness and decided to get a stock exhaust system. And I did.

Low RPM's are much smoother now, I can't discern the difference between the mid RPM's, and top RPM's are a bit harder to climb (only when travelling fast already, 130km/h) Idle is perfect.

In my entire time owning the bike there were no sputterings, no back fires/misfires, no flames, no problems starting, no smoke.

Im going to get a hold of an exhaust gas analyzer and see my rich/idle problems once my bike is together. 2 weeks.

**The CyberPoet** · 03-28-2005, 11:18 PM

Originally posted by 89katana750

In my entire time owning the bike there were no sputterings, no back fires/misfires, no flames, no problems starting, no smoke.

So what makes you think it's running rich/lean/out-of-wack if you're not getting any issues with sputtering, back-fires, misfires, etc? How old were the plugs? If the plugs were on there since you bought it (over 5k ago), they might simply be old...

Cheers
=-= The CyberPoet

**ThAzKat** · 03-29-2005, 12:13 AM

What you explained tells me there was no back preasure meaning no idle. there has to be some back preasure, if there isn't then you have a problems at idle. top end should be better without back preasure because of the gases being forced throught the system and Cyber might agree with that. You need the intake breathing to be equal with the exhaust breathing for a good running bike, so to speak.

**The CyberPoet** · 03-29-2005, 12:54 AM

Originally posted by 89katana750

With the stock exhaust on it it still doesn''t misfire/sputter. The only thing I noticed different was the low rpms being smoother and the high rpms climb slower, but not unusually slow, just slower in comparison.

That sounds simply like the different natures of the exhaust -- the larger headers breathed better at high RPM's than the smaller stock ones do... If you're not getting any signs of misfire, and the plugs weren't reasonably new when you checked them, be happy -- it sounds like there's really nothing wrong (and you can always go back the old exhaust header and simply put a better sounding can on it, like a Hindle).

Cheers
=-= The CyberPoet

**89katana750** · 03-29-2005, 01:09 AM

It funny how you mentioned the spark plugs being old. They are actually very old. 12,000km old

. Don't worry I bought new ones.

The reason I am concerned about the richness is because the info I gathered was that I had to rejet. I didn't know that it would sputter/misfire etc. if it was too rich/lean. I don't think I have much of a problem anymore but I am still going to see with the gas analyzer.

THAZKAT, what do you mean about the backpressure? what does that feel like?

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