Jump to content
Sign in to follow this  

Smart Carb on my CR500

Recommended Posts

hey man- i imagine you could add one on a cr250. i like the button a lot. it automatically pops off once the bike starts and it makes the bike substantially easier to kick over. the 500 won't usually start using the button when it is cold. however, once warmed up it will fire right up. roostius maximus did mine for me. Look him up on here and send him a pm.

 

They will fire cold with the valve open if you rabbit kick them (2 rapid kicks). It took me awhile to un-learn the 500 starting procedure myself.

Edited by jar944

Share this post


Link to post
Share on other sites

jar944 you have the slickest decomp mod I have ever seen, no welding just thread in the adaptor bushing or sleeve. how deep are you drilling into the stud boss and what thread are you taping into it? how close do you get to the hole in the stud boss and finally what size hole through to the compression chamber?

Share this post


Link to post
Share on other sites

Thank you for the info. I will get ahold of him and see if something can't be done. That can be my excuse to buy a new stock head which will raise my compression up and then see how the bike responds to that and some race fuel. Hopefully there is enough material in the head so he can do his thing. I haven't been able to find any info on anyone doing this to a 250, but surely I'm not the first.

Share this post


Link to post
Share on other sites

jar944 you have the slickest decomp mod I have ever seen, no welding just thread in the adaptor bushing or sleeve. how deep are you drilling into the stud boss and what thread are you taping into it? how close do you get to the hole in the stud boss and finally what size hole through to the compression chamber?

 

The head is tapped 8x1.25. I don't remember off hand how deep it was.  The through hole started @ .080" and i think I ended up around .120". Its a start small and work up process since it will vary depending on your valve.  You want about 115 PSI compression with the valve open. its possible to go lower but it gets hard to start.

 

I got the idea from some decomp install pics on one of the cr5 sites, they made me realize there was enough material to tap.  Same pics partway down the page (post 114):

http://forums.everything2stroke.com/threads/49513-How-It-s-Done-Projects-around-the-Shop/page12

Share this post


Link to post
Share on other sites

see next post for link

Edited by rodgini

Share this post


Link to post
Share on other sites

Great video :)

thanks man. i have bunch more video but i suck at uploading apparently. + the video quality went to shit. bike is rippin though. 

Share this post


Link to post
Share on other sites

F2200DFE-D69D-469F-ADDE-828474D9119E-225

 

 

Hey man which radiators and guards are you running?

those are unabiker cages. however, due to them not fitting my over-sized radiators, i went with mohard racing guards. man they are works of art. 

Share this post


Link to post
Share on other sites

those are unabiker cages. however, due to them not fitting my over-sized radiators, i went with mohard racing guards. man they are works of art. 

Cool I've been eye balling those too. Which oversized rads are those? Are those meant for that frame or was there a lot of modding to get them to fit?

 

Cheers

Share this post


Link to post
Share on other sites

Cool I've been eye balling those too. Which oversized rads are those? Are those meant for that frame or was there a lot of modding to get them to fit?

 

Cheerthose are chinese radiators off of ebay. they were made to fit that frame but i had to modify the spigots to accept the cr500 plumbing.

Those are chinese radiators off of ebay. they are made for the crf chassis. i had to modify the spigots to accept the cr500 pluming though,

 

mohard sells guards made for over-sized radiators. they are pricey but when open the package you see why. 

Edited by rodgini

Share this post


Link to post
Share on other sites

Sorry bud, - my preffered mount is the CRF-X and it gets no FI yet. Your logic is somewhat flawed though if your thinking its pointless to mess around with carb'ed 4 strokes --- it seems doubly pointless to dink around with bikes that have been obsolete since at least 2007, or in the 500's case, 2001

So if somebody is "wasting" their time making stuff for decades old 2 strokes - (the most current incarnation of the CR5 dates back to 1989, and a YZ250 dates back to '99 ) -- why wouldn't they apply similar logic to a 2 or 3 year old 4 stroke?

Share this post


Link to post
Share on other sites

If you are still wanting to have better carb results on your crf, I recommend you contact TokyoMods. They have a carb mod for the FCR carbs. You can send yours in or purchase an entire carb. Since I live in Canada I just purchased the entire carb for an 04 CRF250. It was bang for buck the best single add on I've ever realized. You won't be disappointed.

Share this post


Link to post
Share on other sites

I somewhat recently added a complete ignition system off a 1999 cr250. flywheel, stator, cdi etc. The bike runs even better than ever. Cold starting is no longer a problem. I had it out in below freezing temps last week and it ran great. i just clicked it a few clicks richer. So i've had it from 90+ to below freezing without making any major changes. A total of 6 clicks lean to rich from winter to summer. No real altitude test but went from 0-3500 ft without making any changes. I also changed premix from Klotz to Torco GP-7 with no changes required. Plug still looks perfect. 85 hours and counting on the SC.

 

can you guys argue about 4-strokes elsewhere that was not the point of this thread.  

Edited by rodgini

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×