How would this 250R setup run...

[04'400ex'er]

I am kinda new to the whole 250R scene here. I am seriously contemplating buying a 250r instead of a new 450r. I am just wanting to know how a 250R with a full exhaust, K&N, airbox removed, 265 bore weisco prolite, v force reeds and cage, cool head, and a cr 250 ignition would run compare to the 450s. would that setup be a good reliable motor? I am just looking for ideas about how the power and hp range would be compared to newer machines. any help or ideas about things i should or shouldnt do are greatly appreciated.

[TheFontMaster]

With that setup the motor is enought to beat a stock, or piped 450 in a drag. The motor should be putting out 35-40 horse power, check in the dyno section, I think there was a dyno sheet from a 250r that was similar to the one you have. The CR ignition is more for MX raceing, it has a lighter CR250 flywheel. Does it have any suspension mods to it? Because you easily get a 250 to out handle any of the newer quads out there. What year is the motor? If it is using an 86 piston, you are set for many more bores. If it is using the 87-89 piston, then the cylinder is on it's last bore, so you would ether have to get a new cylinder, or get this one re-sleeved. They make the 86 piston in bigger bores than the 87-89 pistons. You could also put an 86 piston on the 87-89 rod, and add a spacer plate to the bottom of your cylinder.

[hondardr4life]

Fontmaster, I have a spacer plate setup in my motor, so I'm assuming its an 86 piston on the 89 bottom end. So what your saying is that if I bore it to a 265 (.080 over), I will still have bores left after that??

[04'400ex'er]

Originally posted by TheFontMaster
With that setup the motor is enought to beat a stock, or piped 450 in a drag. The motor should be putting out 35-40 horse power, check in the dyno section, I think there was a dyno sheet from a 250r that was similar to the one you have. The CR ignition is more for MX raceing, it has a lighter CR250 flywheel. Does it have any suspension mods to it? Because you easily get a 250 to out handle any of the newer quads out there. What year is the motor? If it is using an 86 piston, you are set for many more bores. If it is using the 87-89 piston, then the cylinder is on it's last bore, so you would ether have to get a new cylinder, or get this one re-sleeved. They make the 86 piston in bigger bores than the 87-89 pistons. You could also put an 86 piston on the 87-89 rod, and add a spacer plate to the bottom of your cylinder. I dont have a 250R yet... My main question is how the power would be with this setup on a 250R to help make a decision on whether or not to go that route or buy a new 450R. Those are just the motor mods that I would do to the motor if i got one. Also are there any other easy mods that I didnt list to help the 250 out on power? and what is the difference in years of the R? like what would be the best year to purchase because I know that honda made some changes to it during the production time. and finally, how much would a port job on the mods i listed help it out? thanks for the help.

[beerock]

you need all that and a decent port job...

[baker250r]

id say go with a bigger carb.... 38 or 39. if u want a more snappier motor, get the cr250 reed cage assembly. pretty much a good port job, and matching pipe, u shoudl tear it up all over creation.

[TheFontMaster]

Originally posted by 04'400ex'er
I dont have a 250R yet... My main question is how the power would be with this setup on a 250R to help make a decision on whether or not to go that route or buy a new 450R. Those are just the motor mods that I would do to the motor if i got one. Also are there any other easy mods that I didnt list to help the 250 out on power? and what is the difference in years of the R? like what would be the best year to purchase because I know that honda made some changes to it during the production time. and finally, how much would a port job on the mods i listed help it out? thanks for the help.


The 86 motors were a short rod design, they used a different rod, and piston than the other years. The 86 will rev higher and quicker, but they wear on the motor is also a little more. The 87-89 used the same set up, a longer rod, and a piston to match that. Somewhere along the way honda changed, I think it was the exaust ports, but I'm not shure exactly what changed. The transmission in the 86/87 had a taller 5th and 6th gear. The only other thing I can think of that changed was the clutch. The 89 had the best clutch and used a needle berring design. A port job is one of the best things you can do to get more power out of a 2 stroke motor. Ask around you will be able to find a place that does good work.