Posts
527
Joined
2/1/2015
Location
Lakeland, FL
US
Edited Date/Time
8/31/2015 9:57pm
Hi
Deciding on a carb upgrade. Your opinions valued. My 83 RM250 has 82 head, DG pipe, V-force reeds. I think she has stock ports.The carb is stock flat slide. Jetting is good and she runs well. Looking for more power. I've had good results with PWKs,,and decising between a 38mm air strike from 99 CR250,,,or 39.5 from a 500. I race sand MX primarily in intermediate level.
Thanks
Brian
Deciding on a carb upgrade. Your opinions valued. My 83 RM250 has 82 head, DG pipe, V-force reeds. I think she has stock ports.The carb is stock flat slide. Jetting is good and she runs well. Looking for more power. I've had good results with PWKs,,and decising between a 38mm air strike from 99 CR250,,,or 39.5 from a 500. I race sand MX primarily in intermediate level.
Thanks
Brian
My advice, if you haven't done so already, would be to invest in suspension upgrades, you will be able to attack the track much harder a 1mm bigger carb will not make you any faster. Bore the stock 38 and try it, have someone log lap times.
I have already got gold valves in both ends and been tweeking front and back to my taste.
Normally I wouldn't go bigger than the 38 on a 250,,,but I have had amazing results going from 32 VM round slide on my 1980 YZ125 to a 35mm PWK. I gained not onlyon top but off idle all the way up.
I know micro sprints using 250s often go 39-41 with PWKs so I was thinking I maybe able to gain on top more with the PWK.
Brian
I've thought about going a similar route on my '82 RM250. It's kind of exciting that as much as a top-end stormer the bike already is, going to a different carb (perhaps slightly larger) would give it even MORE top-end.
Have y'all looked at taper-boring the carb instead? Wouldn't that increase the Venturi effect, kind of a best of both worlds? I recall this was a popular mod on SCR bikes in the early '90s.
I'm sure excited to see the results of this project. I've wanted to mount a PWK to my '82 250Z to see how it would work .. But have never gotten around to it! Maybe this winter.
Most of the 40s I see, do not have the air striker fins,,which is I think a important feature for MX with the on/ off nature.
I'll give this 38 a try,,,then decide if I'll want more. The worst is I'll have a extra carb for another bike.
I'm wondering if the Dicks Racing mod of a power jet in the venture with dial is worthwhile? I've had 1-2 old mikunis with this that I never got to play with. Any experience on this?
Last weekend I raced the RM and stayed with a heavily modified 86 YZ490 to the first corner(4th gear),,,I thin pivoted under him and stole the holeshot award at the first jump at corners exit. The 83 RM250/with 82 head and DG pipe/vforce has sum spunk. I find 1-2 more bike lengths of power on the starts and she'll be a missile.
The Shop
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