I need more power 650L

Thanks guys. I am gonna add a Wiseco 101mm 10.25:1 piston (I got on Ebay much cheaper the JE) and a order a hotcam. I will do the work myself this winter when its to cold to ride, and here in Nebraska it isnt far away. There are 2 dyno's nearby Ill post my results when its in.

No, I don't mean worn out bearings, although I agree they too should be changed.

What I'm saying is that the small end of the rod has no bearings where it meets the piston pin. You need to check the difference between the OD of the new pin and the ID of the rod hole. If it's beyond service limit you may get a knocking sound that is sometimes mistaken for valve train noise.

...just something to check before it's all buttoned up.:thumbsup:

yeah i havent heard anyone who has put hi comp piston/cam combo with an aftermarket rod. If your only going to 11-1 or less im sure it will last quite a while.

rod knock? you mean worn out bearings but that has nothing to do with the strength of the rod just fare wear and tear that you have to up keep. Hi comp just puts a tad more strain on the rod so bearings wont last quite as long as with stock compression of 8.3-1, but these motors are proven for 15 years now with MANY MANY Ls that have had highly modded engines with very low failure rates. Any engine hop-up or rebuild should consist of all new bearings and all, But this goes for ANY engine you just dont upgrade one thing without usually doing something else to make the whole package strong and reliable

Thanks guys. I am gonna add a Wiseco 101mm 10.25:1 piston (I got on Ebay much cheaper the JE) and a order a hotcam. I will do the work myself this winter when its to cold to ride, and here in Nebraska it isnt far away. There are 2 dyno's nearby Ill post my results when its in.

studded ice tires!

With the mods youve mentioned you should make high 40's RW HP.

My 675 (102.4mm wiseco) made just under 50 with hotcam, 10.25:1, 42.5 slide carb, open intkae and open exhaust with mild gas flowed head. So Id expect you'll notice the difference! :oD

Getting anywhere near 55-60HP takes a lot more work and careful rebuilding Im afraid :thumbsup:(

basically you cant build a "streetable" xrl with 55-60 HP.

IMHO, I think its possible (assuming you can get 97RON+ fuel), but it takes a lot of effort and would possibly difficult to start.

Ive found that Ive lost no bottom end power with extra tuning/porting, but just gained a lot of top end and midrange. The D shaped exhaust ports help a lot here. They flow more than a round port but the D shaping gives extra midrange power due to less exhaust gas recirculating back into the comb. chamber. I think cosworth were possibly the first to use it and its now standard practice in a lot of race engines.

One thing is for sure, a XRL with 50 HP should be achievable without sacrificing too much practicality.

IMHO, I think its possible (assuming you can get 97RON+ fuel), but it takes a lot of effort and would possibly difficult to start.

Ive found that Ive lost no bottom end power with extra tuning/porting, but just gained a lot of top end and midrange. The D shaped exhaust ports help a lot here. They flow more than a round port but the D shaping gives extra midrange power due to less exhaust gas recirculating back into the comb. chamber. I think cosworth were possibly the first to use it and its now standard practice in a lot of race engines.

One thing is for sure, a XRL with 50 HP should be achievable without sacrificing too much practicality.

you dyno that yet? how about the cdi?

Not yet Im afraid....

Ive rebuilt my 675 (blown cyl base gasket) and have a problem with the CDI (NX650). The engine was making just under 55RWHP at 7200rpm with the HSR48 carb, but I have now gone back to my overbored VM40 Mikuni (bored to 42.5 to match the intake) as I found my long manifold for the HSR48 was restricting the intake too much. Ive fitted the VM40 for now as its already set up to fit onto the OE inlet manifold.

Dyno runs will be done very soon as the engine is running, but have a wild erratic pulse (like adouble spark) to the HT coil which has shown on my last three rev counters. I am planning on buying a new CDI to make sure its sorted. Im not sure if to try another NX650 CDI or go with a new XBR one and advance the pulse generator position with the aim of gaining a few RPM. The CDI is now running total loss with no generator and so the clutch is slipping heavily. New Kibblewhite clutch springs are on order off ebay.

I think maybe the CDI has gradually broken down with vibration and the time has come to get it sorted out.

Once I have a baseline for the current set-up I will try the XR600 CDI and genny I have to see if there really is any difference with power/torque. Will also try and change the pulse coil position a few degrees to see if that gives more top end power.

I also have a XBR500 motor to rebuild. New 100mm wiseco piston, hotcam, hotrod, ported head, XL600 lightweight crank and various worn cyl heads to repair (NX650 or XL600) and try. That wont be done till the spring though as I also have a Suzuki RGV285 two stroke engine conversion to build!

I live 4 miles for a dynojet dyno and expect to have a few sessions on there in the winter here in the UK. I promise I will post what I find out as I dont competively race the bike (nothing to hide), just do track days on it for something to break the GSXR / ZX / R6 / R1 etc monotony!!:thumbsup:

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