porting

[brucegregory]

i want to know who is the best person to use to port my kx500 and modify the cyl.head i am going to need the cylinder replated and i am going with the windowed piston but i am at a loss who is the person to use

[kaw rider]

Tell us more about the bike and what you plan are.

[Polar-Bus]

Eric Gorr is reguarded as one of the best porting massager for Kawasakis' but I believe in the past few years he has not been actively porting cylinders anymore.

[brucegregory]

i just plan to play on it i have a friend with a machine shop and i just need to know what works as far as porting i know from my jetskis by raising and widening the exhaust port it really wakes them up but i know the power valve might be in the way for this to have much effect i bought a cylinder from ebay and it need replated so i would like to have it ported and replate the cylinder and also use the windowed piston and mill the head a few thousands but i still want to keep my low end i know porting robs the bottom end,also the reeds i have changed the petals and i was wondering about them i just dont know if it will make a lot of difference using the other reeds i went with the boydson reeds

[jfabmotorsports.com]

If you just plan to play on it I would not raise the compression ratio. If you change the cc's the head more than a little bit you will be have to run better than pump gas, I'm sure you know that but I'm just pointing it out. If it were mine I would leave the ports alone, port the piston, freshin it up and go play with it.

JFAB

[brucegregory]

well i bought the bike last year it is an 2003 for $1700 dollars it had maybe 10 hours on it the first thing i did was put a good clutch in it and changed the reeds just the petals,it is in excellent shape starts first good kick and it really is strong but i want more power i bought another cylinder and i want to port it and mill the head but i still want to run pump gas,i like the bike and it will wheelie in the first 3 gears just rolling the throttle it will in 4th but only if the tire has quit spinning so much but i have a one tooth larger front sprocket on it i didnt like the orignal counter sprocket it was geared too low i thought i weigh 240 so i am not a light weight and i have had a lot of bikes i just thought the kx would hit harder when it got on the pipe i remember my friend had a honda cr450 they only made it one year in 1981 and it would flip over in all 4 gears when it hit but that was years ago when i rode it and i was 100 pounds lighter my bike was running 92 on the gps and it probably could of got a little more if i tucked in but it is hard to do when i was on the street holding my trucks gps in my hand

[ShadeTreeFab]

i just went through my motor, i could not believe the amount of casting flash in cylinder. clean up the ports, windowed piston, cometic hi per gasket kit, v2 reed block, pc2 pipe. with the piston, v2 and gasket kit you would not even know its the same bike.

[Hillclimb#42]

i just went through my motor, i could not believe the amount of casting flash in cylinder. clean up the ports, windowed piston, cometic hi per gasket kit, v2 reed block, pc2 pipe. with the piston, v2 and gasket kit you would not even know its the same bike.

Agreed. Leave the head alone unless you plan on running VP fuel. Pipe and Vforce reeds add alot of power to stock cylinder. Power does cost money, but guessing at porting just costs money without the desired results. Its also easy to jet when mostly stock configuration.

[Polar-Bus]

well i bought the bike last year it is an 2003 for $1700 dollars it had maybe 10 hours on it the first thing i did was put a good clutch in it and changed the reeds just the petals,it is in excellent shape starts first good kick and it really is strong but i want more power i bought another cylinder and i want to port it and mill the head but i still want to run pump gas,i like the bike and it will wheelie in the first 3 gears just rolling the throttle it will in 4th but only if the tire has quit spinning so much but i have a one tooth larger front sprocket on it i didnt like the orignal counter sprocket it was geared too low i thought i weigh 240 so i am not a light weight and i have had a lot of bikes i just thought the kx would hit harder when it got on the pipe i remember my friend had a honda cr450 they only made it one year in 1981 and it would flip over in all 4 gears when it hit but that was years ago when i rode it and i was 100 pounds lighter my bike was running 92 on the gps and it probably could of got a little more if i tucked in but it is hard to do when i was on the street holding my trucks gps in my hand

By adding 1 tooth larger on the front sprocket, you are gearing higher, and your acceleration will suffer. It's just the way gearing reacts. The additional fact you weigh 240 is not helping either. Run 14/49 gearing and you will get a great compramise of acceleration and good top end speed. Don't waste your time with high compression porting IMO. Here's my famous words quoted from a long time respected engine builder: "It's far easier to loose 5 hp than it is to gain 3 hp "

[jfabmotorsports.com]

I run 15/50 on the AF. It is almost the same as stock gearing for a KX500(14/47) but the larger counter shaft gear is easyer on the chain. I also run 50's on my KX450's so the the bonus is I can swap wheels if I need to. I keep 3 different tires mounted on 4 wheels all with 50 tooth sprockets.

JFAB

[RoostDaddy]

Eric Gorr is reguarded as one of the best porting massager for Kawasakis' but I believe in the past few years he has not been actively porting cylinders anymore.

Eric is still doing KX500 motors, along with about all others, I have talked to him recently.

[DoldGuy]

Eric Gorr is reguarded as one of the best porting massager for Kawasakis' but I believe in the past few years he has not been actively porting cylinders anymore.

Eric is still doing KX500 motors, along with about all others, I have talked to him recently.

Roost,
What did he have to say about your head (16-18*)?

[Polar-Bus]

Eric Gorr is reguarded as one of the best porting massager for Kawasakis' but I believe in the past few years he has not been actively porting cylinders anymore.

Eric is still doing KX500 motors, along with about all others, I have talked to him recently.

Nice,
I do remember reading a few years ago Eric opted to take some time away from porting to focus on family issues.... I have heard first hand Eric ports some killer hp cylinders...

[RoostDaddy]

Eric Gorr is reguarded as one of the best porting massager for Kawasakis' but I believe in the past few years he has not been actively porting cylinders anymore.

Eric is still doing KX500 motors, along with about all others, I have talked to him recently.

Roost,
What did he have to say about your head (16-18*)?

Doug,
I really didnt have much time to talk to him because he was busy, it was just an update on how things were working and some other feedback.  All i know is what I've already posted about the head.  Reducing comp. and letting it rev.

[cbxracer30]

Eric didn't step away with family issues , he was working tightly with a couple MX teams trying to make the new 250F's out run the competition. A couple of years ago it was tough to get him to work his magic, But I just talked last Tuesday about a go fast 80 cylinder and I'm packing one up to ship to him, the last one he did for me the competition couldn't touch, just ask Big Hair  .CBX