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Premix ratios for plated 2 strokes?

Posted: December 13th, 2010, 4:16 pm
by Widow Maker
Does anyone run a different ratio for their plated bikes versus dirt only?

Posted: December 13th, 2010, 6:07 pm
by seanmx57
I mix for the RPM I'm turning not the cylinder makeup.

I have a nikasil jug on my CR5. 40-1 for MX,

The 250 gets 32-1

Posted: December 13th, 2010, 6:25 pm
by qkenuf4u
im running 32:1 with 927 or YAMALUBE (927 is to much $$$$) but ive also geared it to keep it off the pipe at cruise.. still need to get my DGN/DGJ/DGL needle :? ....

Posted: December 13th, 2010, 6:48 pm
by Widow Maker
I appreciate the input, guys.

I think I'm going to run my usual 32:1 with 927 and see where the RPMs are at with the type of street riding I'll be doing and go from there.

Posted: December 13th, 2010, 7:00 pm
by NightBiker07
He's talking plated, like for the street, not the plated cylinder bore.

depending on the RPM you will be turning, i would go with 32:1 if your pegging her out a lot. if not, 40:1 would be perfectly safe. if you really "lug" her around, 50:1 wouldnt be unreasonable with good oil, and if you are gonna put some miles on her, it would be cheaper for sure.

Posted: December 13th, 2010, 7:06 pm
by 100hp honda
brit mixes for the amount of sand that will pass through the bearings on that particualr day :lol:

Posted: December 13th, 2010, 7:11 pm
by Widow Maker
NightBiker07 wrote:He's talking plated, like for the street, not the plated cylinder bore.

depending on the RPM you will be turning, i would go with 32:1 if your pegging her out a lot. if not, 40:1 would be perfectly safe. if you really "lug" her around, 50:1 wouldnt be unreasonable with good oil, and if you are gonna put some miles on her, it would be cheaper for sure.
Yeah, I think cruise RPM is going to be perhaps the biggest factor here. I won't be jumping on the interstate with the thing, but there are some stretches of country road where the speed limits are in the 45-55mph range. Most are single lane stretches where riding the "slow lane" isn't an option. It's either I keep up with traffic or I'll have traffic backed up. Regearing to keep it off the pipe at cruise would hurt my ability to run tight single track.

I think 927 at 32:1 should keep me in the safe zone and that also simplfies things as I'll be running the same ratio for my other CR500. No dealing with different premixes for different bikes.

Posted: December 13th, 2010, 7:28 pm
by qkenuf4u
if only it was that easy.....

my first motard was built by a hare-scramble guy outta new york and it was set up TITS !!!!
BAJA DESIGNS light kit
E-LINE stator
IMS 4 gallon tank
IMS WIDE RATIO TRANS
not sure of porting/gearing/carburation since i bought it set up... all i know is it would cruise down the road at 60mph as smooth as my zrx1100 street bike... i could run all day long (well 75 miles anyways) and it never acted like a 2-stroke other than riding wheelies outta the corners, exhaust note and leaving my street bike buddies 5 corners back :cool:

fast forward to my 92 i just got done building. im running 15/46 gearing and it still wants to be on the pipe at cruise. im gonna try the RIGHT needle in my PWK first before i change my gearing anymore. that might help in how it runs at cruise but im guessing im gonna have to gear it a bit more to get it a bit tamer/off the pipe..

Posted: December 13th, 2010, 7:30 pm
by Widow Maker
What was the first year for the wide ratio trans?

Posted: December 13th, 2010, 7:33 pm
by qkenuf4u
i seen it listed awhile back.. i know my 92 is NOT a wide ratio... but i dont think the OEM wide ratio trans is gonna be WIDE ENUFF with normal gearing... :?

wish they still made the IMS trans kit.... i missed one on ebay when i was building my motor... :cry:

Posted: December 13th, 2010, 7:34 pm
by NightBiker07
Widow Maker wrote:What was the first year for the wide ratio trans?
the wide-ratio trans he is talking about is an aftermarket get-up....practically unavailable.

I would think that setting her up to cruise 60mph off the pipe shouldnt be too much of a problem after fiddling with gearing. and short bursts to 100 shouldnt be out of line either.

Posted: December 13th, 2010, 7:37 pm
by qkenuf4u
NightBiker07 wrote:
Widow Maker wrote:What was the first year for the wide ratio trans?
the wide-ratio trans he is talking about is an aftermarket get-up....practically unavailable.

I would think that setting her up to cruise 60mph off the pipe shouldnt be too much of a problem after fiddling with gearing. and short bursts to 100 shouldnt be out of line either.
yep exaclty.. mine would run out to 90mph+ without a problem... :cool:

Posted: December 13th, 2010, 7:41 pm
by Widow Maker
NightBiker07 wrote:
Widow Maker wrote:What was the first year for the wide ratio trans?
the wide-ratio trans he is talking about is an aftermarket get-up....practically unavailable.

I would think that setting her up to cruise 60mph off the pipe shouldnt be too much of a problem after fiddling with gearing. and short bursts to 100 shouldnt be out of line either.
I know the IMS is aftermarket. The mention of a wide ratio trans made me think of when Honda changed the ratio in the 500. The year they changed it eludes me.

Posted: December 13th, 2010, 7:54 pm
by Rhino89523
88 - 92 was the close and '93 they switched to the wider gears until death of the beast.

Posted: December 13th, 2010, 7:56 pm
by Widow Maker
Thanks.

Posted: December 13th, 2010, 11:40 pm
by bearorso
Do as you said you were going to do with oil ratios. Makes it easy. No re-jetting etc. I've always run much leaner than 32:1 on oil, and had no problems, but you should stick to what you've got it jetted to.

Something to think about is the Intelajet - it's on another thread here. I'm going to put one on, as, whilst currently most of my riding is in tight stuff, so I have the jetting perfect, a couple of times I've gone riding with blokes who do more open stuff, thread links between trails on fast stretches of tar, or wide open fire trail. And over the Xmas / New Years break I'll be going on a long ride with these blokes. The Intelajet would enable me / you to fatten up the jetting for peace of mind, then turn it back to what you want when back in the real dirt. It's a simple, adjustable power jet (sort of - it sprays pre-emulsified fuel in, not a stream of raw fuel that a conventional power jet delivers), from what I can see. A good idea for a 2t that is going to see a lot of variety in riding conditions / areas.

Posted: December 14th, 2010, 4:16 am
by Widow Maker
bearorso wrote:Do as you said you were going to do with oil ratios. Makes it easy. No re-jetting etc. I've always run much leaner than 32:1 on oil, and had no problems, but you should stick to what you've got it jetted to.

Something to think about is the Intelajet - it's on another thread here. I'm going to put one on, as, whilst currently most of my riding is in tight stuff, so I have the jetting perfect, a couple of times I've gone riding with blokes who do more open stuff, thread links between trails on fast stretches of tar, or wide open fire trail. And over the Xmas / New Years break I'll be going on a long ride with these blokes. The Intelajet would enable me / you to fatten up the jetting for peace of mind, then turn it back to what you want when back in the real dirt. It's a simple, adjustable power jet (sort of - it sprays pre-emulsified fuel in, not a stream of raw fuel that a conventional power jet delivers), from what I can see. A good idea for a 2t that is going to see a lot of variety in riding conditions / areas.
Interesting. I'll give it a look. Thanks!

Posted: December 15th, 2010, 12:59 am
by 2T500
On my street legal 500 I'm running premix 40:1, gearing is 42/15, engine is 87 in a 97 steely so the same tranny ratios as the 93 onwards, jetting in the 39 PWK is only slightly rich with 55 pilot and 180 main, still altering the jetting to suit back road use but it really likes the 55, probably spends a lot of time on the pilot, keen to look at a power jet for extra fueling on demand and then should be able to drop the main a size or two.

street

Posted: December 16th, 2010, 3:03 pm
by kball1313
I run 50:1 Amsoil Dominator in all my 500's and 250's. This includes a street legal supermoto, a bike I only run in the dunes and a woods 250. The biggest problem with all these posts is people not knowing how to jet an engine in the first place.

32:1, 40, 50 whatever. I've never had a top end seizure that wasn't my own fault (sucking a base gasket in and not wanting to wait for a tow out of the sand)

You'll find on the street your throttle will be only about 1/4 open at cruise speed, you'll never get rid of the surge completely no matter what others say.

I run 50:1, 17" wheels, 14 or 15/40. Don't ride like a pussy, but i'm not a pro either. When you do ride with pros, like a few of my friends are, you really realize how slow me and most other riders actually are.

There's a million different oils and ratios that a million more guys have had success with. That's my recipe and it works for me.

Another tip is keep a mixing bottle in your backpack and make 1/2 gal graduated marks on the side of your tank so if and when you have to mix fuel in your tank, you'll get the ratio as close as you can to perfect.

Re: street

Posted: December 16th, 2010, 5:31 pm
by qkenuf4u
kball1313 wrote: you'll never get rid of the surge completely no matter what others say.
my first cr5 tard i had back in rainsylvania would cruise 60mph as nice as my zrx1100...no surge, no blubbering nothing but PERFECT cruise.. sadly i didnt build that bike so i dont know the porting/jetting :cry: .... one big thing that helped it was the IMS WIDE RATIO trans that was in it..... would do 90+mph all day ... would cruise all over the back roads and not complain.... really wish i knew ALL the specs on that bike... :( but YES the surge can be dialed out if you want to mess with it long enough.. i need to gear my new AF500 up a bit more (45 now) and it will be alot better at cruise... :cool:

surge

Posted: December 16th, 2010, 6:55 pm
by kball1313
Let me know when the gearing fixes how an engine runs it and i'd love to come try it out.

Re: surge

Posted: December 16th, 2010, 7:04 pm
by qkenuf4u
kball1313 wrote:Let me know when the gearing fixes how an engine runs and i'd love to come try it out.
well going from the 48 to the 15/45 made a huge difference in how it runs at cruise but its still not 100%.... still gotta do some jetting (DGN needle) ..
youre gonna tell me LOWERING the rpms isnt gonna change how a bike runs at cruise ??? :?:

Re: street

Posted: December 16th, 2010, 7:08 pm
by AlisoBob
qkenuf4u wrote:..my first cr5 tard i had back in rainsylvania would cruise 60mph as nice as my zrx1100...no surge, no blubbering nothing but PERFECT cruise..
Would the ZRX take off from a red light in 5th too?

:roll:

cruise

Posted: December 16th, 2010, 7:17 pm
by kball1313
Sure it will if you're talking about a specific speed. Dial it best you can at 60. More importantly the bike should be ridden hard enough you'll never know the difference anyway.

Everyone's got their own bikes, and they're all a bit different in some way, so when you do come up with your combo, post it up. I'm curious to see what it ends up at and it's more productive than arguing simple things.

I'd rather help than piss on each others feet. Mines 50:1 dominator, 94 pump gas, 39pwk, 14/40 for around town, pc pipe, Q silencer, 178/52 at sea level. Now my porting is the factor that throws anything out the window. Runs strong and works. Clean burn, no spooge.

My steely motard was all stock, down to the pipe and I ran it stock 175 main and one up on the pilot. Pretty decent, but always had a surge at some speed.

Having a street legal 500 to jet is a problem we're lucky to have. There's a lot of dudes that would love to have a problem like that.

Re: street

Posted: December 16th, 2010, 7:39 pm
by qkenuf4u
AlisoBob wrote:
qkenuf4u wrote:..my first cr5 tard i had back in rainsylvania would cruise 60mph as nice as my zrx1100...no surge, no blubbering nothing but PERFECT cruise..
Would the ZRX take off from a red light in 5th too?

:roll:
actually i have in 3rd and never knew it... remember its called TORQUE.... :roll: