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All your engine questions here......

53526 Views 416 Replies 165 Participants Last post by  wrennus
You guys have a bunch of good questions on this forum, but they are spread out. I thought we could put together a thread to consolidate them all.

We are a professional race shop/engine shop that specializes in GSXR motors. We build race motors for Roadracing, dragracing, flat track, street, and SCCA D/C Sportsracers. We also run a 2 rider Pro AMA Roadrace team.

So...if you have any engine building questions what so ever, post them here and I will try to answer them.
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When are you getting the codes to come on? Like give me all the details, speed, rpm, amount of boost.

Do you have a fuel pressure gauge?

The reason its breaking up is because its way too rich.
When are you getting the codes to come on? Like give me all the details, speed, rpm, amount of boost.

Do you have a fuel pressure gauge?

The reason its breaking up is because its way too rich.
When i first noticed the problem it would breal up around 6k-7k rpm and would have a hard time pulling past that. The FI light would only come on under hard acceleration. Normal round the town driving seemed fine. I changed the plugs to see if that was the problem and put good gas in it. Plugs looked good upon inspection, no white spots on the plugs signaling detonation. Took it out for a long ride normal driving. Stopped and made a few blast and it seemed to pull alot better with out breaking up but still with some hesitation but not nearly as bad as before. Made about 4 passes all together. 2nd pass the FI light came on. Accidently turned off bike so i cldnt get the code, on the 4th pass got it to come on and thus the Codes. All 4 passes where way better than before; maybe because of the plugs, im not sure? But it wasnt nearly as bad and Rpms reached up to 14k if memory serves me correct. I noticed some hesitation during all these runs but nothing nearlly as bad as before. The FI light goes off when the bike it shut off and doesnt come on again until hard acceleration; sometimes. I also just noticed what looks like coolant leaking from some where? Not sure what its about, but im about to take the fairing off and see where its coming from. I thought the issue was being caused by a lean condition? What should Fuel Pressure be at idle, so I can check next time.
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You might have a high spike in a spark stick? Gotta get that code out. It is saved in memory and it may take so many key starts to clear the ECU itself. I think I read that in the FSM. So, even if in phantomode is what you are experiencing, that phantom code is stored and if you can get that spark stick code say, it might be a spark stick #3 is just a diagnostic guess over the net. Might not be it at all me chasing tail not knowing that code. Fun trying though.

Then again, it could be the ECU. Might be a registry someplace in the upper a-N signal not making it in the diode is circuit board relay or some sort of internal integrity breakdown is another possibility, but I doubt it.

Could be a harmonic connection at the connectors are momentarily losing a signal, spike the code, reconnect inside the connector pins and the code clears on it's own which is an ECU working correctly.

Yes, the plugs could be the better tune most likely in my opinion, (might agree with yours on plug swap). That was your only change to the same phantom code spike(s). Fuel pressure is about 43 pea yes I would give or take a pound either way idle or running.
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I've got a '95 750. The previous owners only rode it 7600 miles in the last 13 years, with only 1,000 miles being put on in the last 8yrs. I rode it 3700 miles and then it started losing power. I checked all the valve clearances and they are all within spec except one that was .001 off. Compression is 50's to 80's across the board. Could this be carbon deposits built up on the piston rings keeping them from expanding which wore them and is causing blowby? Any other thoughts on what it could be? I'm going to clean the pistons w/ induction cleaner over the next couple days and then try to see if I get compression back. Any thoughts would be helpful.

I have a few random questions if you don't mind.

Have you ever tried zero gap rings and if so what was your experience? I am interested in them to be sure.

Building an 07 G1K motor for drag racing and hopefully lots of N2O. What top and 2nd ring gaps should I be looking for? It's J&E + 2mm (or is it 3?)

I was told .013 top, and .014 2nd. But I do not understand why the 2nd would be more? Also the stock ring end gaps butted together causing this build, and I don't want the same thing to happen again. Want the gaps as tight as possible for the non N2O pass's, but don't want to take a chance of running it too tight and having them fail again.

what squish for this motor? I was planning on trying to get to .027, as I have tried that before on a NA 04 G1K and it did not touch :) But honestly I am new to motor building and don't know if a tight squish is bad with N2O?

the bike has 8 injectors. My understanding is that the bottom four run most of the time, and the top 4 only come on at high rpm at big throttle settings. When they come on are the bottom 4 still working? We just got another power commander to use in conjunction with our other one so we can map it using all eight, though to be honest I have never hooked two up to the same bike and don't really understand how it works.

We have a multi function hub with the user switch and currently have custom street and N2O maps, which will be retuned once the motor is back together.

any power to be found with valve clearances?

does a Busa oil pressure relief valve have a higher release pressure than a G1K's?

what can be done to increase the reliability of this motor? we already have the higher volume oil pump gear. We are using stock crank and rods.

Does KWS have a cnc program for 5 vlave R1 heads?

Thanks, sorry for all the questions.
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Hey, im new to the forums. I am having a hard time finding engine parts for my 93 gsxr 750. I just purchased the bike form a neighbor who had the top end completely disassembled. I need to purchase a new cylinder, rings, and possibly a new piston. Do you guys have any advice as to where I should look to purchasing these parts.
I've been having the cutting problem that many on the forum have written in about. I put the bike into dealer mode and got the following codes. C32 thru C35 which appear to be the secondary injectors codes, and C49 which I can't find a reference to. Any help would be appreciated.:banghead
'05 ecu corroded connector pins

Hello all,

I managed to cartwheel my bike last year at a track day and destry the rear subframe and crush the PC3. I've just managed to put it all together with a new PC3 but the bike wouldn't start. Showed Chec on the guage. Tried to get the eroor code but it wouldn't show. I pulled the ecu to check for a clean connection and notice corrosion at the base of some of the pins and on the one side it appear that there is a pin missing/broken from corrosion. Having never taken this off before I don'y know if it's a broken pin or should there be a space there. Can anyone tell me if there should be 2 full rows of pins or is there supposed to be a gap where one pin may go?

Any help appreciated,

OK guys, have answered my own question....managed to fish a broken pin out of the plug so it's quite obvious there should be a full row of pins. What a waste of a good ecu...can't use it with a missing pin...........

Great forum. thanks for all the help from the guys who know what they're doing.....
I have an 04 GSXR 600 with 26k on the clock and just bought an engine with 1.8k on it to swap out. The new engine has been sitting for 2.5 years.... any suggestion before putting it in other than obvious ones (New oil, new filter)? Any advice would be greatly appreciated.
i would prime it by hand and while priming turn the motor over by hand a few times. also it wouldnt hurt to spray some WD40 in the cylinders before doing this. other then that new oil, plugs etc.
question about idling problem...

sup guys im brand spankin new on this website and ridin bikes... i just traded my 88 supra for a 1992 suzuki gsxr 750.. it has 30,000 miles.. now.. i researched alot about this problem i have but nothing is really exactly how mine is.. okay so when the choke is off, even after i warm up the bike, it will die. and it only stays alive if the choke is half way on which revs about 3k. but if the choke is off i would have to open the throttle a little to keep it alive.. anyone know what i can do? once again i am brand spankin new with this bike stuff :dunno .. so i dont really wanna get into taking the bike apart unless i get specific instructions n stuff.. haha.. please get back to me asap.. thanks!

p.s i bought some seafoam and put it in the tank today.. also got some carb cleaner.
OH and another thing! when i go on speed bumps, after the back tire comes off the bump the bike would stall sometimes.. even with the clutch down..
Guys. have a question for yall. Im from Moscow (Russia), and Im planning to have a turbobike from US to the next summer. I dunno will I order an already turboed bike, or just a turbokit. We got a few dynostands here, but the prices for the each run are really high (300$), and my question is: is it possible to tune fine AFR using wideband commander only testing bike on a streets, without dynostands? Or it is not accurate enougth to do it?

much appriciated in advance.
I have a 2003 gsxr 600 thats is missinge around 11000 to 13000 under load. If if run through the rpms slowly it does not miss buth when your on the throttle wide open it misses horribly. any ideas of what it could be?
I have a 750 water cooler which I really like. Want to increase engine power was thinking about either putting a 1100 motor in or boring it to a 907 cc motor . What do you think? Will I need to make head modifications if I do the 907?
i am looking at skimming the head or top of the block on my 01 gsxr 600 k engine am using in my hovercraft instead of using thinner yoshi head gasket. how much could i machine of them without the valves hitting the pistons. i will bw using gsxr750 intake cam on intake and 1000 exhaust on the exhaust side with adjustable sprockets so can dial them in and either 2 0r 4 degree ignition advance. i am looking at getting the power in mid to top end as engine will be at max revs 90% of the time.

Any help will be much appreciated

cheers all:burnout

I have a 2000 750 and currently at the shop to swap out for a 2003 750 engine. My question is - Are there after market engine mounting brackets available ? Holes are not aligned.
Hey. What do I need to mount a 2003 750 engine on a 2000 750 frame ? Sorry about the double post new to the forum . Trying to get answer ASAP because I am on my way to the bike shop after work.
I received a 95 gsxr 1100w from my cousin that he had sitting in his garage for a few years. The bike only has 45,000 miles on it but is not running well, I have no compression in cyclinder #2. Is it going to be cheaper to have the engine rebuilt or to purchase a new engine. I was also wondering if I am doing any damage to the bike by riding it? It runs just obviously not much pick up.

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