To port or not to? RM 250

NorcalVet
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Nor-cal, CA US
Edited Date/Time 3/13/2015 5:49pm
So I'm looking for more power everywhere, but mostly off the bottom to mid. Should I look for the the right person local or wait and do a 265/295. Vet nov

05 RM 250, it's actually running real good right now. But some tracks/ obsticals it just feels like it needs a little more sometimes.

Will some porting do the trick, or should I suck it up and save my $$$ for more seat time, tires, etc. Btw the suspension is revalved and good.

Oem top end
V-3 reeds
PC works pipe and 304 silencer
Oem clutch & WC perch
10oz ffw
JD jet kit (sea level)
165 main
42 pilot
Red taper needle / 3rd clip

Also>> using Sunoco 110 leaded
-- for consistantcy & crispness
927 @ 32-1 (zero smoke & spooge) Smile



I know a vortex ignition would be probably a good option,but I can't locate one.

But would the right port job deliver


|
bvm111
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Las Vegas, NV US
3/11/2015 9:50pm
I sent my 2006 KX250 cylinder and head to Tom Morgan and talked to him directly on the phone about what I wanted and he delivered..... smoother pick up on the bottom, broader mid range and more over rev! I love it, not pipey at all and fun to ride.... that being said I was just thinking to myself... what if I did a big bore Wink Laughing
JM485
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Davis, CA US
3/11/2015 10:15pm
Have you tried messing with the powervalve spring to move the power around a bit? I screwed with it a bit on mine before I tore the bike apart for a rebuild, but once I get it back together I'm definitely going to test it a bit more. Maybe try turning it 1/8 turn looser to get the valve to open a bit earlier?
Bruce372
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3/11/2015 10:29pm
i had a 2005 RM250 and bumped it to a 265, and it was different but not really better.

it really is a good stock engine, with pipe etc. if you port it, it might make more power but not necessarily better.

if you can find some ultimate 4.4 VP race fuel, that will make more power than anything!
urbanlift707
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Humboldt, CA US
3/11/2015 11:42pm Edited Date/Time 3/11/2015 11:44pm
NorcalVet wrote:
So I'm looking for more power everywhere, but mostly off the bottom to mid. Should I look for the the right person local or wait and...
So I'm looking for more power everywhere, but mostly off the bottom to mid. Should I look for the the right person local or wait and do a 265/295. Vet nov

05 RM 250, it's actually running real good right now. But some tracks/ obsticals it just feels like it needs a little more sometimes.

Will some porting do the trick, or should I suck it up and save my $$$ for more seat time, tires, etc. Btw the suspension is revalved and good.

Oem top end
V-3 reeds
PC works pipe and 304 silencer
Oem clutch & WC perch
10oz ffw
JD jet kit (sea level)
165 main
42 pilot
Red taper needle / 3rd clip

Also>> using Sunoco 110 leaded
-- for consistantcy & crispness
927 @ 32-1 (zero smoke & spooge) Smile



I know a vortex ignition would be probably a good option,but I can't locate one.

But would the right port job deliver


Try and FMF pipe, I've heard the pc has less bottom than stock even and focuses it up top. I've never tested that as I've only had one pipe but that's the word.
I'm hopefully headed to e street next weekend for the Othg race.
I've got an 06 rm 250
Stock porting
FMF fatty and power core
V3
Stock flywheel
sunoco 110 with 927 32:1 as well. She runs crisp, I'd love to swap bike for a lap or two and see what the pipe and flywheel weight are all about.

The Shop

3/11/2015 11:48pm
stock front pipe will give you better power delivery bottom to mid than a pro circuit- fmf gnarly pipe will give you even more (but you sacrifice a bit of top end) - 165 main jet seems very lean!! we run 178 main jet in mine- I run a lot less oil than you aswel (use motul 800 factory line at 50:1
3/12/2015 1:35am
@bruce 372 , u can use u4.4 in a 2stroke? im not sure , I used it in my 450 all year last year and it works alsome!! never tried it with a smoker, I know it oxygenated but it works good with the smokers? made my 450s efi very finicky until I found the proper mapping
nytsmaC
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3/12/2015 3:30am Edited Date/Time 3/12/2015 3:33am
If it were mine..

How many hours on the top end?

Optimize your deck height with the appropriate thickness base gasket, then measure the head.

Use those measurements to get your head modded for race gas.

Switch to Renegade SX2 gas, you will have to rejet.

After doing that if you're still looking for more try a Bill's or FMF pipe, get the cases matched and porting touched up.

Head mod, SX2 gas and jetted accordingly will give amazing results.
3/12/2015 3:48am
nytsmaC wrote:
If it were mine.. How many hours on the top end? Optimize your deck height with the appropriate thickness base gasket, then measure the head. Use...
If it were mine..

How many hours on the top end?

Optimize your deck height with the appropriate thickness base gasket, then measure the head.

Use those measurements to get your head modded for race gas.

Switch to Renegade SX2 gas, you will have to rejet.

After doing that if you're still looking for more try a Bill's or FMF pipe, get the cases matched and porting touched up.

Head mod, SX2 gas and jetted accordingly will give amazing results.
the fmf fatty pipe is actually very similar to stock on the suzukis- its almost an exact copy just with a slightly larger overall volume. The fatty works well with big bore kits

sst would be no good if he's wanting more bottom end power...

wish we could get race gas as cheap as it is in America!!! costs so much over here we just run on pump fuel
3/12/2015 3:49am
The cheap and effective way: ditch the PC pipe and add a tooth or two to the rear sprocket.

Also make sure to keep your top end fresh.
nytsmaC
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Frig Off CA
3/12/2015 4:21am
nytsmaC wrote:
If it were mine.. How many hours on the top end? Optimize your deck height with the appropriate thickness base gasket, then measure the head. Use...
If it were mine..

How many hours on the top end?

Optimize your deck height with the appropriate thickness base gasket, then measure the head.

Use those measurements to get your head modded for race gas.

Switch to Renegade SX2 gas, you will have to rejet.

After doing that if you're still looking for more try a Bill's or FMF pipe, get the cases matched and porting touched up.

Head mod, SX2 gas and jetted accordingly will give amazing results.
the fmf fatty pipe is actually very similar to stock on the suzukis- its almost an exact copy just with a slightly larger overall volume. The...
the fmf fatty pipe is actually very similar to stock on the suzukis- its almost an exact copy just with a slightly larger overall volume. The fatty works well with big bore kits

sst would be no good if he's wanting more bottom end power...

wish we could get race gas as cheap as it is in America!!! costs so much over here we just run on pump fuel
It's expensive up here too, $20-25 USD per gallon. The oxygenated, leaded stuff runs incredible though.
Trav138
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PA US
3/12/2015 6:06am Edited Date/Time 3/12/2015 6:52am
How long have you had the flywheel weight? Have you tried bike without it. You may like it better without the fww. Just a thought and others have suggested good ideas.
slipdog
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3/12/2015 6:47am
Yes, you should get it ported. There's a lot of room for improvement in port timing and head design.
Bruce372
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3/12/2015 6:49am
from memory, the 2005 head spec was pretty good, it was either 1.2 or 1.5mm squish gap.

I ran the PC with the 304 shorty, but the bottom end wasn't there- the factory fatty with the stock silencer worked best with great top end. the 304 shorty would crack at the bracket too.

be careful messing with base gaskets, the engine cases aren't machined totally flat where the cylinder bolts up, and if you aren't careful you can get an air leak.

the single ring wiseco YZ250 GP piston works good.

on the 2005, you can also upgrade by using the carb manifold and reed spacer from a yz250, its shorter and makes the engine noticeably crisper- they did this upgrade on the 2006 models

I always ran jetting 162-165 main with 110 leaded.

and yes, you can run the U4.4 in a smoker, IMO it is the best way to make more power. oxygen and lead, good stuff.
Ted722
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3/12/2015 6:56am
I have a stock pipe from an '06 you can have. Worked great on mine if your looking for more low to mid. It's worth mounting just to feel the difference from a PC.
JM485
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3/12/2015 7:56am
Ted722 wrote:
I have a stock pipe from an '06 you can have. Worked great on mine if your looking for more low to mid. It's worth mounting...
I have a stock pipe from an '06 you can have. Worked great on mine if your looking for more low to mid. It's worth mounting just to feel the difference from a PC.
If the OP isn't interested, any chance I could hit you up for that? I live in Davis during the week and could pretty easily make the drive to pick it up.
NorcalVet
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3/12/2015 9:18am
Thanks for all the feedback everyone, keep it coming.

I'm interested in specific in porting/ altering timing which is probably the direction I want to go..... Not interested in a pure built race motor. Just closer to my RMZ 450 out of some the corners/ shorts exits before jumps/ doubles etc!


At Ted, got your text. I'll take it to try it out. Maybe est or Oatfield

At anyone wanting to try it for some laps, come on over a run it.

Top end is less then 10 hrs (guesstimate). And I just added the ffw not to long ago. Smoothe the hit somewhat, but what I was looking for was to clean up the wheel spin and have the suspension settle down on some tracks especially later in the day. Worked!

Slip..... Any suggestions on who Whistling
Ted722
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3/12/2015 9:27am Edited Date/Time 3/12/2015 9:27am
NorcalVet wrote:
Thanks for all the feedback everyone, keep it coming. I'm interested in specific in porting/ altering timing which is probably the direction I want to go...
Thanks for all the feedback everyone, keep it coming.

I'm interested in specific in porting/ altering timing which is probably the direction I want to go..... Not interested in a pure built race motor. Just closer to my RMZ 450 out of some the corners/ shorts exits before jumps/ doubles etc!


At Ted, got your text. I'll take it to try it out. Maybe est or Oatfield

At anyone wanting to try it for some laps, come on over a run it.

Top end is less then 10 hrs (guesstimate). And I just added the ffw not to long ago. Smoothe the hit somewhat, but what I was looking for was to clean up the wheel spin and have the suspension settle down on some tracks especially later in the day. Worked!

Slip..... Any suggestions on who Whistling
I think what you're describing is why Suzuki made so many changes to the '06 motor. There's a lot of write ups on what they did. Crankcase volume, porting, intake, etc.

Riding it back to back with the RMZ is almost a curse...(I know I've ridden you're '11 and it's sweet). Knowing that you're going to EStreet, I'd pull that 10oz flywheel weight and try it out on the sand without it.

I used to run a 7oz on my KX250 for offroad and that's all I wanted. Didn't want to smooth it out too much. But for moto? Never messed with a flywheel weight on a stock motor for moto.
NorcalVet
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3/12/2015 7:01pm
Hey Ted
- I say adding the ffw helps more w/ smoothing out the busyness of the suspension especially in acceleration bumps because it lessens the wheelspin which helps it hook up better and doesn't jar the "f out your back if you don't happen to sit up right away... IMO Smile

I just threw a new set of chain and sprockets on .... Maybe I'll order a 52 to try at Hangtown & Oatfield

But back to porting... Any pros and cons for specifically the '05?

Paging Digger to the white courtesy phone.... Any input on specifics !!
Chadillac661
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Phoenix, AZ US
3/12/2015 11:39pm
NorcalVet wrote:
So I'm looking for more power everywhere, but mostly off the bottom to mid. Should I look for the the right person local or wait and...
So I'm looking for more power everywhere, but mostly off the bottom to mid. Should I look for the the right person local or wait and do a 265/295. Vet nov

05 RM 250, it's actually running real good right now. But some tracks/ obsticals it just feels like it needs a little more sometimes.

Will some porting do the trick, or should I suck it up and save my $$$ for more seat time, tires, etc. Btw the suspension is revalved and good.

Oem top end
V-3 reeds
PC works pipe and 304 silencer
Oem clutch & WC perch
10oz ffw
JD jet kit (sea level)
165 main
42 pilot
Red taper needle / 3rd clip

Also>> using Sunoco 110 leaded
-- for consistantcy & crispness
927 @ 32-1 (zero smoke & spooge) Smile



I know a vortex ignition would be probably a good option,but I can't locate one.

But would the right port job deliver


I have a Varner built 2006 RM250 and it is amazing. Super fast with a wide, easy to ride powerband and tons of over-rev.

Cylinder and head mod, 39.5 mm taper bored carb, matched cases and a Vforce.

I did a fair amount of testing (Bills, PC, FMF and DEP) and I feel the Bills pipe is hands down the best (rider preference of course)

You can see in the pic below how far off the cases were when he started grinding on them, something like 3mm if I remember correctly?

I will post a pic of the carb mods too, pretty trick carb setup.

I run a 185 main, JD red needle in the 4th clip and a 45 pilot at sea level. Its hungry.





Ted722
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3/13/2015 5:43am
NorcalVet wrote:
Hey Ted - I say adding the ffw helps more w/ smoothing out the busyness of the suspension especially in acceleration bumps because it lessens the...
Hey Ted
- I say adding the ffw helps more w/ smoothing out the busyness of the suspension especially in acceleration bumps because it lessens the wheelspin which helps it hook up better and doesn't jar the "f out your back if you don't happen to sit up right away... IMO Smile

I just threw a new set of chain and sprockets on .... Maybe I'll order a 52 to try at Hangtown & Oatfield

But back to porting... Any pros and cons for specifically the '05?

Paging Digger to the white courtesy phone.... Any input on specifics !!
Trust me I love flywheel weights...for the right application. 10oz is a lot for a stock motor on a 250! I have an 11oz for my 500 for off-road only right now...haven't tried it yet for moto.

Last time I checked you're not doing woods riding on the East Coast. I left my '06 gearing stock (49 on back). I've had many people ride it of all abilities with no issue. I wouldn't go anymore than a 50 out back on your '05. A 52 will no doubt get you that un-intended wheel spin you're not looking for in motocross. Supercross? Sure, run the 52. But outdoor loamy/hardpack (and in some cases sand) stay close to stock gearing....less is more my Team Suzuki brother! Smile
3/13/2015 6:00am
Sheriff245 wrote:
The cheap and effective way: ditch the PC pipe and add a tooth or two to the rear sprocket. Also make sure to keep your top...
The cheap and effective way: ditch the PC pipe and add a tooth or two to the rear sprocket.

Also make sure to keep your top end fresh.
Jody?
3/13/2015 8:08am
Sheriff245 wrote:
The cheap and effective way: ditch the PC pipe and add a tooth or two to the rear sprocket. Also make sure to keep your top...
The cheap and effective way: ditch the PC pipe and add a tooth or two to the rear sprocket.

Also make sure to keep your top end fresh.
Jody?
Common sense?
Bruce372
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3/13/2015 8:15am
MXA has never given a bad review on a PC pipe! its almost like there is some conflict of interest or something! Wink
NorcalVet
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3/13/2015 8:32am Edited Date/Time 3/13/2015 8:33am
Here's some specific info on some of the changes for the diff years
Here
Post #6

A lot more changes from 03-08 then I thought !!

@ Ted so your 06 came w/ a 49

I guess Suzuki in 06 misplaced Jody's memo, because my 05 came w/ a 50 Smile

They were probably going for more of a mellow-trackable motor set up just like their new 05 RMZ .... Which I drank the koolaide on!
Chadillac661
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3/13/2015 8:39am
Bruce372 wrote:
MXA has never given a bad review on a PC pipe! its almost like there is some conflict of interest or something! Wink
Look at the paid advertising in MXA by Pro Circuit and it will all make sense.
Bruce372
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3/13/2015 8:42am
Bruce372 wrote:
MXA has never given a bad review on a PC pipe! its almost like there is some conflict of interest or something! Wink
Look at the paid advertising in MXA by Pro Circuit and it will all make sense.
I think there is even more to it than that! Wink
3/13/2015 8:58am
Bruce372 wrote:
MXA has never given a bad review on a PC pipe! its almost like there is some conflict of interest or something! Wink
Look at the paid advertising in MXA by Pro Circuit and it will all make sense.
Bruce372 wrote:
I think there is even more to it than that! Wink
Well, they do publish their whole catalog inside MXA, so there's that. But yes, there's probably more.
Madmax31
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3/13/2015 10:48am
Bruce372 wrote:
MXA has never given a bad review on a PC pipe! its almost like there is some conflict of interest or something! Wink
You're wrong. I did see an article once where they tested a few pipes on a bike and the PC didn't come out on top. Can't remember the article but was surprised. Also they've noted certain pipes as being the best on a certain bike, such as a Dr D on the older CRF450's.
3/13/2015 1:12pm
I run an 8 oz steahly on my 03 RM250 and it can still get an ugly hit when I don't want it to. Then again, I think I forgot how to properly ride a 2-stroke! Didn't seem t be a problem in the 80's/90's...
I have also heard about the Bill's pipe to be a great match for the RM's. I have a fatty and a stock pipe. I will have to try the stock again. I did a slide change on the carb and that cleaned up the power delivery.
NorcalVet
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3/13/2015 1:52pm
Just remember... RM = Race Machine


Best $$$ spent for an extra spare fun/ race bike !!! Smile

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