GSXR400 SP race bike info

**Quasievil** · 3rd October 2005, 11:04

Hi all a bit off a long shot but Im trying to find some information on how some other GSXR400 SP race bikes are set up , mostly interested in gearing and other mods done to the bike.
I have searched heaps on the net for some info but getting nought in return ,of interest anyway.
I raced Yesterday and had a few problems with speed, Im running a 47 tooth on the rear and a 13 tooth on the front (recently reduced from a 14 ) the bike was spluttering after about 11000-12000 rpms , I need the last 2500rpms to get the max speed out of the bike, My mates gsxr400 (not an SP) was whipping me on the straights. I should be getting more speed out of it.
Any advise or help or other will be appreciated.
Im thinking of getting the bike Dyno tuned soon to get it right as well

**bugjuice** · 3rd October 2005, 11:07

if it's spluttering at high revs, then that would point to a fuel starvation, wouldn't it..?? If you get the fuel flowing right, then you get the power sorted, then get the gearing sorted - would have thought.. Have the carbs had any work done on them? Compression in the cylinders good? and a good spark? May be get a compression test done

**Quasievil** · 3rd October 2005, 11:12

Originally Posted by bugjuice

if it's spluttering at high revs, then that would point to a fuel starvation, wouldn't it..?? If you get the fuel flowing right, then you get the power sorted, then get the gearing sorted - would have thought.. Have the carbs had any work done on them? Compression in the cylinders good? and a good spark? May be get a compression test done

Yeah hear ya mate, fuel is likely. will be getting the Carbs soughted out at the shop soon.
I really have no idea about the condition of the engine and carbs as I have focused on other things clutch suspension etc, the engine does run sweet and I have had zero issues with it, but now I think yes its time to examine this further

**James Deuce** · 3rd October 2005, 11:12

Coil. 10 chars.

**FROSTY:Me** · 3rd October 2005, 11:13

Originally Posted by Quasievil

Hi all a bit off a long shot but Im trying to find some information on how some other GSXR400 SP race bikes are set up , mostly interested in gearing and other mods done to the bike.
I have searched heaps on the net for some info but getting nought in return ,of interest anyway.
I raced Yesterday and had a few problems with speed, Im running a 47 tooth on the rear and a 13 tooth on the front (recently reduced from a 14 ) the bike was spluttering after about 11000-12000 rpms , I need the last 2500rpms to get the max speed out of the bike, My mates gsxr400 (not an SP) was whipping me on the straights. I should be getting more speed out of it.
Any advise or help or other will be appreciated.
Im thinking of getting the bike Dyno tuned soon to get it right as well

Mate I told ya --you need to gear it up

**FROSTY:Me** · 3rd October 2005, 11:15

actually mate I think ya need to talk to Mr slim (slims partner)
Theres a guy he bought his bike off of that really knows gixxers

**Quasievil** · 3rd October 2005, 11:21

Originally Posted by Jim2

Coil. 10 chars.

Explain Mr Jim for a retard ?

**Quasievil** · 3rd October 2005, 11:23

Originally Posted by FROSTY

Mate I told ya --you need to gear it up

The gearing would have been perfect if I could rev it out.......... I think, Im going to put the 14 back on it anyway. this should give me more top end right, slower of the mark but better on the straights

**bugjuice** · 3rd October 2005, 11:41

Originally Posted by Quasievil

Explain Mr Jim for a retard ?

if the coil is poked, it won't be able to fire a spark fast enough at high revs, which is also cause spluttering and misfiring. High voltage replacement coils (for your bike) could be an idea over stock ones if they do need replacing, since the bike is going to be spending more time at higher revs. Also check the leads too (no cracks, tight seals at the connections).. But as for the question, do they need replacing, that could/would be part of the elimination process of engine work. If they look knackered (and check for cracks in the unit), then the could be past their peak. But I'd get the carbs looked over and a compression check done too, to start with

Sorting out the clutch and suspension etc is obvisouly needed, but don't forget to look at the bike as a whole package! Brakes etc too!
Regular oil changes, checking plugs often, even take the head off the block (if you know what you're doing) and inspect the cylinders and fit a good compression gasket etc.. Depends on how far you (and your wallet) want to go. Looks like a sweet bike too, so it'd be a shame not to have the performance to go with the looks

**FROSTY:Me** · 3rd October 2005, 11:41

Im beginning to be suspicious of that bike mate-- given our convo the other day.I just wonder if its soposed to have flat slides fitted to it.
Brett Please PLEASE -do yaself a favour and give it to Gary at GP trading.
Let him run it up on the dyno for ya and see if some jetting changes will let it rev out propperly.
The trouble with a race bike is the only way to tell how well its gonna go is on the track BUT a really good second place is the dyno.
You're going through the same shit I did with mella yella last year.As soon as it was rejetted and a couple of minor tweaks gary did it started to show its true potential.

**James Deuce** · 3rd October 2005, 11:41

Originally Posted by Quasievil

Explain Mr Jim for a retard ?

I KNOW you're not one of them.

Are you running total loss? Check that your power supply is sufficient to generate spark at high RPM. Lack of electrical juice will manifest itself in a high RPM misfire, just when you don't want it. If your ignition coil is not generating enough energy for a decent spark it may also do the same thing.