PNW Riders

micknwop · 11-04-2009, 07:49 AM

So im working on a 2001 cr250r. It has a procircuit pipe. I'm trying to figure out a good jetting for seattle elevation (or close), and also climate.

It is currently running

22.5
420
6beh2-76 on the 2nd clip from top

And, where can i get just a few jets to try it out without buying a whole set?

Cheers

pscook · 11-04-2009, 09:34 AM

I buy my jets at Lake City Powersports. Aurora Suzuki more than likely has them as well, but Lake City is closer to me. Walk in with an example of the pilot and main, just because.

I don't know what you will run for specific jetting, but I wouldn't worry about needles right now, get the main and pilot close then work on needle. A lot of issues can be dialed around the needle. Do you have a mixture determined yet? What about gas, pump or race? Oil brand?

micknwop · 11-04-2009, 02:28 PM

probably 31:1 with honda red bottle.

both of those places are reasonable distance.

research shows most people running around 30+ and 400. Maybe i need to pick up a few jets

erickb · 11-04-2009, 03:01 PM

give me 2 beers, 5 min and a test ride and jets will be the last thing you will need to fix

side not I went through a lot of jets on my RM until I found one that worked, I have no idea the size but I kept changing them until I liked the way it rode

pscook · 11-04-2009, 04:50 PM

Originally Posted by micknwop

probably 31:1 with honda red bottle.

both of those places are reasonable distance.

research shows most people running around 30+ and 400. Maybe i need to pick up a few jets

32:1 is a lot easier to mix than 31:1. A side note is that 20:1 made the most power, but make sure that you are mixing according to the bottle. For example, don't run a 40:1 oil at 32:1, or vise versa. It took me the better part of a day to get my RZ even close to rideable, but with the baseline sorted it is a complete blast to come on the pipe.

Are you comfortable with jetting? Do you know what you are looking for? I have a bunch of links somewhere that I pored over when I was building my RZ. If I find them I will pass them along, unless, of course, you know what you are doing upon which time I will STFU.

Just remember that adding more oil to the gas will make the bike run leaner on a particular jet size. Basically, if it is hot out and you don't want to mess with jetting just add more oil to the mix. Conversely, subtract oil form the mix if it is colder. The oil will displace fuel during the combustion process. Just food for thought.

Alanjtc73n · 11-04-2009, 05:55 PM

Whatcha need?...

I've got some mains and pilots you can try if you like. Oh...and you're welcome to a bottle of Motorex 2-stroke oil if you like. I like redline for my dirtbike and A747 for the RS125s.

Does this mean we get to go dirtbike riding when you get it sorted out?

micknwop · 11-04-2009, 07:49 PM

Originally Posted by pscook

32:1 is a lot easier to mix than 31:1. A side note is that 20:1 made the most power, but make sure that you are mixing according to the bottle. For example, don't run a 40:1 oil at 32:1, or vise versa. It took me the better part of a day to get my RZ even close to rideable, but with the baseline sorted it is a complete blast to come on the pipe.

Are you comfortable with jetting? Do you know what you are looking for? I have a bunch of links somewhere that I pored over when I was building my RZ. If I find them I will pass them along, unless, of course, you know what you are doing upon which time I will STFU.

Just remember that adding more oil to the gas will make the bike run leaner on a particular jet size. Basically, if it is hot out and you don't want to mess with jetting just add more oil to the mix. Conversely, subtract oil form the mix if it is colder. The oil will displace fuel during the combustion process. Just food for thought.

im not an expert but i know when something isnt running how it should. Im doing a small tear down since the bike has been sitting for a while. First time it's seen sea level so im sure i need to change the jets, figured id do it while its apart.

Originally Posted by Alanjtc73n

Whatcha need?...

I've got some mains and pilots you can try if you like. Oh...and you're welcome to a bottle of Motorex 2-stroke oil if you like. I like redline for my dirtbike and A747 for the RS125s.

Does this mean we get to go dirtbike riding when you get it sorted out?

Hmmm, i would venture i'd need in the realm of 390, 400, 410.... and also 30 and 32 i would gues.

anything else you want to give me

and yes, i need to change the fork seals, greese some bearings, get a chain, rejet, and maybe some tires. Then we're she's good for a trial run.

Alanjtc73n · 11-04-2009, 09:21 PM

It sounds like you have "carburetor 2". Are the mains slotted? I've got a whole assortment of the hex but only a few of the slotted. I'll take a look and see what I've got. The 420 main you got is good for a stock bike at sea level. Your slow jet sounds weird. They should go from 25 to 45.

coastiepete · 11-04-2009, 09:35 PM

Originally Posted by Alanjtc73n

Whatcha need?...

I've got some mains and pilots you can try if you like. Oh...and you're welcome to a bottle of Motorex 2-stroke oil if you like. I like redline for my dirtbike and A747 for the RS125s.

Does this mean we get to go dirtbike riding when you get it sorted out?

Redline FTW. 50:1?

Motoxfox12 · 11-04-2009, 09:48 PM

thats too lean for an 01 CR^

coastiepete · 11-04-2009, 09:52 PM

Originally Posted by Motoxfox12

thats too lean for an 01 CR^

ahhh. that's what we were running on an RM.

pscook · 11-05-2009, 05:59 AM

Originally Posted by Motoxfox12

thats too lean for an 01 CR^

You mean rich, right? Too much gas, not enough oil.

StageRulz · 11-05-2009, 08:11 AM

WoW.....there are some really "Keyboard Jockeys" play'in tech around here.

micknwop · 11-05-2009, 08:13 AM

Originally Posted by Alanjtc73n

It sounds like you have "carburetor 2". Are the mains slotted? I've got a whole assortment of the hex but only a few of the slotted. I'll take a look and see what I've got. The 420 main you got is good for a stock bike at sea level. Your slow jet sounds weird. They should go from 25 to 45.

the main is a hex, but the slow jet is a slotted. I'm gone this weekend, i'll give you a ring maybe we can meet up next week.

Originally Posted by StageRulz

WoW.....there are some really "Keyboard Jockeys" play'in tech around here.

Im open to more suggestions.....

pscook · 11-05-2009, 09:07 AM

Originally Posted by StageRulz

WoW.....there are some really "Keyboard Jockeys" play'in tech around here.

How so? Most of the posters either have experience jetting a two stroke in general, or a CR250 in particular. How is that being a "Keyboard Jockey"?

Alanjtc73n · 11-05-2009, 09:34 AM

50:1 can be run okay if you want to try to get the most power out of it. I believe the manual says to run 32:1. My CR125 runs 20:1. It's a little smokey but works well for woods riding. I just replaced the top end this weekend and the cylinder has no wear on it. The piston had some blow-by but everything else looked great. I'm sticking to 20:1. If you plan on doing top ends more often, then you can get away with 50:1. If you don't want to hone out your cylinder every top end then run it closer to 32:1. All depends on what you want to do with it. If you're putting in a new top end, you should run it with more oil and a slightly bigger main as it breaks in. Then you can taper off and rejet if you want more power.

Hawker · 11-05-2009, 11:17 AM

Try reading this and understanding how to determine where your jetting is at, rather than looking for settings on the internet. More than once even experienced tuners have given me jetting settings that didn't work at all on one particular bike. Knowing how to diagnose jetting is a good skill to learn : http://www.thumpertalk.com/forum/sho...d.php?t=412662

moose96kx · 11-07-2009, 09:19 AM

Originally Posted by hawker

try reading this and understanding how to determine where your jetting is at, rather than looking for settings on the internet. More than once even experienced tuners have given me jetting settings that didn't work at all on one particular bike. Knowing how to diagnose jetting is a good skill to learn : http://www.thumpertalk.com/forum/sho...d.php?t=412662

holy info!!!! Nice post dude!

dakh · 11-07-2009, 09:55 AM

Originally Posted by Alanjtc73n

50:1 can be run okay if you want to try to get the most power out of it. I believe the manual says to run 32:1. My CR125 runs 20:1. It's a little smokey but works well for woods riding.

1:20

Do you repack the muffler on that thing after every ride?

Alanjtc73n · 11-07-2009, 12:57 PM

Funny you would say that. I'm on my way to grab some packing. Yes, it does get a little bit of spooge but my buddy that rides it is a noob. Although I'm sure the worn top end didn't help. It's never been a problem for me in the past but I don't ride it anymore since I got the 450. I'd rather it have too much oil than too little. He has a little problem of either not being on the gas enough or too much and being a little slow on the trail heats it up pretty good. The 20:1 prevents me from having to replate the cylinder. Plus, the manual recommends 20:1 but I know that's super conservative. I figure you can't really go wrong with what the manual says.

dakh · 11-07-2009, 01:01 PM

Originally Posted by Alanjtc73n

Funny you would say that. I'm on my way to grab some packing. Yes, it does get a little bit of spooge but my buddy that rides it is a noob. I'd rather it have too much oil than too little. He has a little problem of either not being on the gas enough or too much. The 20:1 prevents me from having to replate the cylinder. Plus, the manual recommends 20:1 but I know that's super conservative. I figure you can't really go wrong with what the manual says.

You seem to sound knowledgeable, is this "replace cylinder" conclusion coming from gobs of experience or you just like to be conservative? I just use what's recommended on my synthetic premix. Used to do 1:40 to be on the safe side but it just spits it out the exhaust and fouls packing very fast, 1:50 seem to be about where it doesn't do much of that and the motor seems to be running better too.

Alanjtc73n · 11-07-2009, 02:12 PM

My experience has always been with RS125's which are quite a bit more sensitive to oil mix and jetting. I've got 3 RS125 cylinders sitting on my bench waiting for a replate which illustrate borderline jetting with constant pre-mix ratios. I do tend to be more conservative since I'm a cheap ass. I believe my spooge problem with the CR125 is more from a jetting and riding style issue than mix ratio. The CR is a bone stock '91 still on it's original cylinder (you can still see the cross-hatching) and stock jetting which I know is a bit rich. I never intended this bike to be a racer - just a spare bike for anyone to hop on and go for a trail ride, thus no need for aggressive jetting or pre-mix. My knowledge on dirtbike "replace cylinder - think you meant replate" is admiteddly low since I haven't had a problem with this particular CR125. But if you're talking RS125 then yes - replates are a fact of life when you jet to a knife's edge.

My CR doesn't spit spooge out the exhaust. Just get a little drip when we're done riding. As for your bike running better from 50:1 to 40:1, that change makes the bike run slightly richer which can effect performance depending on the jetting. Everyone has a different preferred ratio. Engine builders like Swedetech recommend a 20:1 for their engines while others push 32:1.

In the end it's your bike and your jetting. I'm just giving suggestions on what has worked for me. If we were all riding '91 CR125's with identical jetting, same gas, riding location, riding style, etc., then 20:1 works great with a little spooge but no cylinder wear. Thus, it's kind of a moot point to argue pre-mix ratios on different bikes. Although please allow me to make one comment - changing pre-mix ratios should never be a substitute for proper jetting. I know my spooge issue is due to a rich slow jet, worn top end, and inexperienced rider. Not trying to step on anyone's toes who have more experience jetting an 01 CR250 because I have none. Just offering jets to micknwop. I'm confident he'll be able to figure out what works best for him.

dakh · 11-07-2009, 06:39 PM

Thanks for the explanation! I'm 2-stroke illiterate, just lucky my bike's previous owner knew what he was doing since it "just works" so far.


11-04-2009, 07:49 AM	#1
micknwop MotoGP Contender Joined: Sep 2006 From: Fremont I Ride: Therefore, I am!	2 stroke jetting So im working on a 2001 cr250r. It has a procircuit pipe. I'm trying to figure out a good jetting for seattle elevation (or close), and also climate. It is currently running 22.5 420 6beh2-76 on the 2nd clip from top And, where can i get just a few jets to try it out without buying a whole set? Cheers __________________ Follow PNW Riders on Facebook and Twitter


11-04-2009, 09:34 AM	#2
pscook Pit Crew Joined: Jan 2008 From: Shoreline I Ride: GSXR600, CBR600, YZ444, RZ350	I buy my jets at Lake City Powersports. Aurora Suzuki more than likely has them as well, but Lake City is closer to me. Walk in with an example of the pilot and main, just because. I don't know what you will run for specific jetting, but I wouldn't worry about needles right now, get the main and pilot close then work on needle. A lot of issues can be dialed around the needle. Do you have a mixture determined yet? What about gas, pump or race? Oil brand? __________________ Follow PNW Riders on Facebook and Twitter


11-04-2009, 02:28 PM	#3
micknwop MotoGP Contender Joined: Sep 2006 From: Fremont I Ride: Therefore, I am!	probably 31:1 with honda red bottle. both of those places are reasonable distance. research shows most people running around 30+ and 400. Maybe i need to pick up a few jets __________________ Follow PNW Riders on Facebook and Twitter


11-04-2009, 03:01 PM	#4
erickb Mr. PNW Riders 2007 Joined: Jun 2005 From: classified Blog Entries: 2 I Ride: without gear	give me 2 beers, 5 min and a test ride and jets will be the last thing you will need to fix side not I went through a lot of jets on my RM until I found one that worked, I have no idea the size but I kept changing them until I liked the way it rode __________________ Follow PNW Riders on Facebook and Twitter


11-04-2009, 05:55 PM	#6
Alanjtc73n Endorsed Joined: Mar 2007 From: Redmond, WA I Ride: 03 ZX636, 90 FZR400, 97, RS125, 98 RS125, Z50!	Whatcha need?... I've got some mains and pilots you can try if you like. Oh...and you're welcome to a bottle of Motorex 2-stroke oil if you like. I like redline for my dirtbike and A747 for the RS125s. Does this mean we get to go dirtbike riding when you get it sorted out? __________________ Follow PNW Riders on Facebook and Twitter

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11-04-2009, 09:21 PM	#8
Alanjtc73n Endorsed Joined: Mar 2007 From: Redmond, WA I Ride: 03 ZX636, 90 FZR400, 97, RS125, 98 RS125, Z50!	It sounds like you have "carburetor 2". Are the mains slotted? I've got a whole assortment of the hex but only a few of the slotted. I'll take a look and see what I've got. The 420 main you got is good for a stock bike at sea level. Your slow jet sounds weird. They should go from 25 to 45. __________________ Follow PNW Riders on Facebook and Twitter


11-04-2009, 09:48 PM	#10
Motoxfox12 WMRRA Qualifier Joined: Jan 2007 From: Vancouver, Washington I Ride: CBR600RR	thats too lean for an 01 CR^ __________________ Follow PNW Riders on Facebook and Twitter


11-05-2009, 08:11 AM	#13
StageRulz Doom Crew Inc. Joined: Jan 2006 From: Spokane Valley Chapter I Ride: 2002 Silver/Grey & 2008 Black/Grey Vespa's on Steroids!	WoW.....there are some really "Keyboard Jockeys" play'in tech around here. __________________ Follow PNW Riders on Facebook and Twitter


11-05-2009, 09:34 AM	#16
Alanjtc73n Endorsed Joined: Mar 2007 From: Redmond, WA I Ride: 03 ZX636, 90 FZR400, 97, RS125, 98 RS125, Z50!	50:1 can be run okay if you want to try to get the most power out of it. I believe the manual says to run 32:1. My CR125 runs 20:1. It's a little smokey but works well for woods riding. I just replaced the top end this weekend and the cylinder has no wear on it. The piston had some blow-by but everything else looked great. I'm sticking to 20:1. If you plan on doing top ends more often, then you can get away with 50:1. If you don't want to hone out your cylinder every top end then run it closer to 32:1. All depends on what you want to do with it. If you're putting in a new top end, you should run it with more oil and a slightly bigger main as it breaks in. Then you can taper off and rejet if you want more power. __________________ Follow PNW Riders on Facebook and Twitter


11-05-2009, 11:17 AM	#17
Hawker Pit Crew Joined: Apr 2006 From: Seattle, WA I Ride: Too many	Try reading this and understanding how to determine where your jetting is at, rather than looking for settings on the internet. More than once even experienced tuners have given me jetting settings that didn't work at all on one particular bike. Knowing how to diagnose jetting is a good skill to learn : http://www.thumpertalk.com/forum/sho...d.php?t=412662 __________________ Follow PNW Riders on Facebook and Twitter


11-07-2009, 12:57 PM	#20
Alanjtc73n Endorsed Joined: Mar 2007 From: Redmond, WA I Ride: 03 ZX636, 90 FZR400, 97, RS125, 98 RS125, Z50!	Funny you would say that. I'm on my way to grab some packing. Yes, it does get a little bit of spooge but my buddy that rides it is a noob. Although I'm sure the worn top end didn't help. It's never been a problem for me in the past but I don't ride it anymore since I got the 450. I'd rather it have too much oil than too little. He has a little problem of either not being on the gas enough or too much and being a little slow on the trail heats it up pretty good. The 20:1 prevents me from having to replate the cylinder. Plus, the manual recommends 20:1 but I know that's super conservative. I figure you can't really go wrong with what the manual says. __________________ Follow PNW Riders on Facebook and Twitter Last edited by Alanjtc73n; 11-07-2009 at 01:08 PM..


11-07-2009, 02:12 PM	#22
Alanjtc73n Endorsed Joined: Mar 2007 From: Redmond, WA I Ride: 03 ZX636, 90 FZR400, 97, RS125, 98 RS125, Z50!	My experience has always been with RS125's which are quite a bit more sensitive to oil mix and jetting. I've got 3 RS125 cylinders sitting on my bench waiting for a replate which illustrate borderline jetting with constant pre-mix ratios. I do tend to be more conservative since I'm a cheap ass. I believe my spooge problem with the CR125 is more from a jetting and riding style issue than mix ratio. The CR is a bone stock '91 still on it's original cylinder (you can still see the cross-hatching) and stock jetting which I know is a bit rich. I never intended this bike to be a racer - just a spare bike for anyone to hop on and go for a trail ride, thus no need for aggressive jetting or pre-mix. My knowledge on dirtbike "replace cylinder - think you meant replate" is admiteddly low since I haven't had a problem with this particular CR125. But if you're talking RS125 then yes - replates are a fact of life when you jet to a knife's edge. My CR doesn't spit spooge out the exhaust. Just get a little drip when we're done riding. As for your bike running better from 50:1 to 40:1, that change makes the bike run slightly richer which can effect performance depending on the jetting. Everyone has a different preferred ratio. Engine builders like Swedetech recommend a 20:1 for their engines while others push 32:1. In the end it's your bike and your jetting. I'm just giving suggestions on what has worked for me. If we were all riding '91 CR125's with identical jetting, same gas, riding location, riding style, etc., then 20:1 works great with a little spooge but no cylinder wear. Thus, it's kind of a moot point to argue pre-mix ratios on different bikes. Although please allow me to make one comment - changing pre-mix ratios should never be a substitute for proper jetting. I know my spooge issue is due to a rich slow jet, worn top end, and inexperienced rider. Not trying to step on anyone's toes who have more experience jetting an 01 CR250 because I have none. Just offering jets to micknwop. I'm confident he'll be able to figure out what works best for him. __________________ Follow PNW Riders on Facebook and Twitter


11-07-2009, 06:39 PM	#23
dakh Superbiker Joined: Sep 2007 From: Seattle, WA I Ride: the walk	Thanks for the explanation! I'm 2-stroke illiterate, just lucky my bike's previous owner knew what he was doing since it "just works" so far. __________________ Follow PNW Riders on Facebook and Twitter

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