300 owner here, still haven't had the time or money to fix my seized cylinder either! Will get it done after I'm finished on my current project - fitting Microsquirt electronic ignition, Yamaha R1 carburettors and a turbocharger to my car. Give me another month or so!
Current mods: Tyga 300 kit, SS GP pipes and carbon fibre cans. Modified airbox, HRC stuffers, smoothed and polished carburettor throats, Tyga carbon fibre hugger and fender, braided stainless brake lines. Custom black paint job.
Please read the "Advanced Warning" post. This form has been created specifically for 300 owners to address their issues with their motors "and will be heavily moderated [to keep threads on topic]".
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Thank you. _________________ Andy.
NSR-WORLD.COM
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I am the proud owner of 2 300 kits used on my racebike. I only have good things to say about the kit regarding my setup. Matt and I have worked on some small modifications to the kit in the past. I use Wiseco unmodified pistons. One warning which may be obvious, if the pistons get too hot on top, they can deform just slightly to pinch the ring, and thus lost compression from no ring tension, but no damage to the cylinders at all. In fact, if I could get the ring out, the groove could be modded and the piston reused. Otherwise, when jetted properly using the fuel and setup I have, I have wonderful results. _________________ I'd rather be racing on my Harc Pro 1998 NSR250SP that is really tricked out!!!
There's 4 of us in New Zealand now running well sorted NSR300s. We all have them to similar levels of tune with some differences between carbs and reeds etc, but below is the spec of my one.
-Tyga 300 barrels and pistons (Running different deck height and slight porting changes)
-Cases matched to barrels and increased case volume.
-Tyga Chambers (best one's we've tried to be honest!)
-Custom machined inserted cylinder head (not VHM) Compression is as 15.9:1
-Running total loss with Tyga trigger wheel
-Ignitech ignition with mapped power valve and ignition curve and quick shifter
-Custom made wiring loom to delete unwanted wiring
-Stubby HRC spark plugs and caps.
-PJ38 carbs with RS250 inlet manifolds (stock reeds!)
-Custom front and rear subframes
-GSXR k8 forks and wheel up front in custom triple clamps
-Honda RS250 rear wheel
-Ohlins Rear shock and soon to be cartridges up front
-Tsubaki Racing Chain on Tyga Sprockets
-Tyga Handle bars
-Tyga Step kit (with modified and shortened foot pegs)
-Tyga Bodywork
Still in the process of getting the chassis geometry and suspension dialled, however the bike is showing awesome promise getting within 1.5 seconds of the lap record at my local track on it's second outing. This lap time was done on old tyres and a bone stock NSR250 front end which left a lot to be desired.
Power output is at 85hp peak with a good spread from 8k-11.5k With the over square engine revs are severely limited to 12k topped out but with the spread of the power it's not the end of the world. It also gives the crank a much easier time. I'm lucky enough to have a dyno in my workshop so quantifying any changes and comparing results of different parts is easy. It's been a slow process to get up to this power but it certainly noticeable on track. Our competitor in this class is a called a Ozzy450 which takes a modern 600 and removes one cylinder. They are very fast and can get 90hp with the spread of a 600 which makes them very competitive. They hold the F3 lap record at all the tracks in NZ now I believe so it's time a pesky 2 stroke came and upset the apple cart!
That's a great spec of a nsr300 , the next mod you will want is custom pipes . I had a set made and they showed an improvement . I also ran electronic powerjets controlled by the ignitech .
Any pics of your graphs mister ? _________________ NSR300
I'm sure if something can be done with the nasty 150 exhaust manifold angle there are nothing but gains to be had, plus expansion chambers really need to be matched to the capacity/tune.
Matt seems to have ironed out the combustion chamber issues after we sent him an NSR500V head to measure up and cross-reference against 150 and 250 heads. We're still waiting for him to send us a motor to evaluate though! _________________ Andy.
NSR-WORLD.COM
Please keep all responses to Forum posts on the Forum so that others may benefit.
Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.
Neal wrote:That's a great spec of a nsr300 , the next mod you will want is custom pipes . I had a set made and they showed an improvement . I also ran electronic powerjets controlled by the ignitech .
Any pics of your graphs mister ?
Yeah we did experiment early on with chambers, but none that were specifically built for the NSR300.
The best of that bunch without a doubt were the New tyga pipes. The JHAs and the RS pipes offered more over rev but at huge cost to midrange performance.
Two of us here run Lectron carbs, and one of the other run KX250 carbs. Im on the RS carbs as mentioned but they are old and badly worn so I am looking at swapping to the Lectron carbs also. I rode the other NSR with the lectrons and the smoothness of the roll on was like being back on a modern 600 - amazing! They do take a while to setup however as they dont have "jets" as we know rather than fuel rods and fuel screws. But it would seem once they are sorted then they are Golden.
Andy wrote:I'm sure if something can be done with the nasty 150 exhaust manifold angle there are nothing but gains to be had, plus expansion chambers really need to be matched to the capacity/tune.
Matt seems to have ironed out the combustion chamber issues after we sent him an NSR500V head to measure up and cross-reference against 150 and 250 heads. We're still waiting for him to send us a motor to evaluate though!
Interestingly we tried straight exhaust spigots back to back with the bent ones and there was absolutely no difference. This was on the same bike, same day with same tune. It might be more "technically correct" to run the straight spigots but in reality there isn't a measurable difference in my opinion.
The combustion chamber shape is quite extreme compared to the Tyga inserts Matt sells, but there is no way he could sell what we run as a product, there would be holled pistons everywhere! They are designed around a 38m/s maximum squish velocity. We also run the plug much closer to the piston with the electrode sitting 6mm away from the crown of the piston at TDC. The heads gave us some big gains particularly in mid range performance, but I do have a suspicion that we have gone too high in comp.
Sketchy_Racer wrote:There's 4 of us in New Zealand now running well sorted NSR300s. We all have them to similar levels of tune with some differences between carbs and reeds etc, but below is the spec of my one.
-Tyga 300 barrels and pistons (Running different deck height and slight porting changes)
-Cases matched to barrels and increased case volume.
-Tyga Chambers (best one's we've tried to be honest!)
-Custom machined inserted cylinder head (not VHM) Compression is as 15.9:1
-Running total loss with Tyga trigger wheel
-Ignitech ignition with mapped power valve and ignition curve and quick shifter
-Custom made wiring loom to delete unwanted wiring
-Stubby HRC spark plugs and caps.
-PJ38 carbs with RS250 inlet manifolds (stock reeds!)
-Custom front and rear subframes
-GSXR k8 forks and wheel up front in custom triple clamps
-Honda RS250 rear wheel
-Ohlins Rear shock and soon to be cartridges up front
-Tsubaki Racing Chain on Tyga Sprockets
-Tyga Handle bars
-Tyga Step kit (with modified and shortened foot pegs)
-Tyga Bodywork
Still in the process of getting the chassis geometry and suspension dialled, however the bike is showing awesome promise getting within 1.5 seconds of the lap record at my local track on it's second outing. This lap time was done on old tyres and a bone stock NSR250 front end which left a lot to be desired.
Power output is at 85hp peak with a good spread from 8k-11.5k With the over square engine revs are severely limited to 12k topped out but with the spread of the power it's not the end of the world. It also gives the crank a much easier time. I'm lucky enough to have a dyno in my workshop so quantifying any changes and comparing results of different parts is easy. It's been a slow process to get up to this power but it certainly noticeable on track. Our competitor in this class is a called a Ozzy450 which takes a modern 600 and removes one cylinder. They are very fast and can get 90hp with the spread of a 600 which makes them very competitive. They hold the F3 lap record at all the tracks in NZ now I believe so it's time a pesky 2 stroke came and upset the apple cart!
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