'02 Honda CR250?

[mladewig]

I know this question has been asked before and have searched through previous posts but I need some help!

Just one thing to remember that I do not have access to Eric Gorr or any other performance shops.. (I live in South Africa)

I am currently riding a 02 CR250 and as we all know the bottom end pretty much sucks. As I am pretty much a novice rider I spend alot of time in the lower rpm range!

I was wondering what single part would be most beneficial to add some more power to the bottom end? Reeds, pipe etc..

Mike


:)

 

[Studboy]

Probably running a thinner base gasket or having the cylinder base machined to take off some material with the head being modified as well. Do you have access to any sort of a machine shop?

 

[Sandy Whoops]

Start with jetting. Rideablity can be greatly improved with the right carb setup. Get an S8 nozzle and work from there. Most of us never came up with an ideal jet configuration when using the stock S9 nozzle.

After that, probably a FMF Fatty / Shorty pipe & silencer. Too bad you can't access Eric's porting work - the Mo Better port job significantly improves the '02 CR's power band.

 

[marcusgunby]

Anyone can send stuff to the states-even from SA.

 

[mladewig]

marcusgunby - yeah I know that but you obviously have no idea what the shipping charges would be!!
Studboy - There is a guy who does things like that but I am not to sure about his work quality that is why I have second thoughts about doing any machining on the engine.

Sandy Whoops - Jetting is definatly not one of my strong points.. but I guess it is something you should learn to do! When you say S8 where does this jet sit? Main, pilot....

 

[bclapham]

marcusgunby - yeah I know that but you obviously have no idea what the shipping charges would be!!
.

i ship stuff from the US all the time and its not that expensive.

the honda cylinders can be bought really cheap through Eric Gorr since he gets them direct from Service Honda- this way, you only have to pay shipping one way.

add into that, the US dollar is really weak right now so i bet you could get a new cylinder through eric that has been ported, for very, very cheap!!!!!

 

[tyesai]

I want to add more bottom to my 04 cr250 but it is brand new and I can't see sending it off for porting and such untill the engine is going to need to be rebuilt so I just bought a 52 tooth rear sprocket to replace the stock, wich I beleive is 49. I am going to change it tommorrow and hopefully ride it Sat, will try to keep you posted and let you know how it works out.

 

[Sandy Whoops]

S8 nozzle - this is the "tube" that the main jet screws into, and the needle passes through.

Search DRN for more info.

 

[2 Fat Guys Racing]

I,m also interested in this S8 nozzle, Is there a honda part # I should ask for? My honda dealer is terrible at finding stuff. This 02 CR250 has too be the hardiest bike to jet that I've ever come across.

 

[Sandy Whoops]

The S8 nozzle is a Yamaha part - the p/n is 3TC-14141-S8-00. Cost is about $20 - $25. When using an S8, expect to make some jetting changes. Probably 1 size larger main and 1 size richer (thinner) needle. At sea level I've used a 400 main with good results (stock is 380).

Using the stock S9 nozzle, I can get close to the same results as when using the S8. However, after doing some back-to-back comparisons, I prefer the S8.

I'm convinced that needle series offered by Honda for the '02 is less than ideal. A thinner (and / or shorter) straight section and slower taper seems like it may be better. I'm thinking about trying some needles from the '01 CR250 and also modifying an '02 needle. If the ideal needle was available, I don't think the S8 nozzle would be needed.

 

[2 Fat Guys Racing]

I actually have changed the needle already to a 6bey30-75 this helped. Btw the motor is 2mm over and has been ported by Eric, dual stage carbon reeds and a stock pipe. I also am at sea level. I'm running 390 main and 35 pilot. I didn't get much test and tune time before the snow fell here, but basically I'm still rich 1/2 to WOT.