rm1125er01

Member
Jun 16, 2010
14
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Ok so I'm going to put a new top end on my 93 rm 125. I have heard that since I'm boaring the cyl 20 over I'm going to have re-jet.. My question, is there any truth to this?!?

Thanks to all
 

whenfoxforks-ruled

Old MX Racer
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Oct 19, 2006
8,129
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Merrillville,Indiana
I did not jet my first dirtbike, not even the second one. But, at 14 I did read the manual and adjusted the air screw and needle. 15 and a new CR125, I started changing jets. Then I also started metal masturbation porting. Thats another story. But, jetting can make more power changes than any bolt on mod. Except an efi set up!
 
Oct 8, 2010
40
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well i will say, if its being bored .020 thats a .5mm and when i was asking about my bike with a .020 bigger bore i was told probally not needed , but i decided to run with a .080 over bore and that is a 1.0mm bigger bore, i do notice a MASSIVE difference cuz as of right now the jets are HORRIBLY off. ive ordered a few different sizes off ebay cuz i found them quite cheap like 6$ each, and with my like 80$ in ebay bucks i have it prettymuch makes them free. soo as soon as all the main jets i ordered come in cuz the poilt seems fine, for idling and low end, im going to strap the bigger jets in and work on them from there.
 

whenfoxforks-ruled

Old MX Racer
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Oct 19, 2006
8,129
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Merrillville,Indiana
Jets are machined orifices. Cheaper jets, do not flow the same as the oem. Jetting is easy, as long as you are sure you're problem is not elsewhere. Most every dirt bike sold new is jetted rich, not all. Used bikes? Oh boy.
 

rm1125er01

Member
Jun 16, 2010
14
0
I have had this bike for a lil over a year now and have not had the pleasure of jetting It yet. Where is a good place to find good quality jets at a reasonable price??

Sorry it took so long to respond, my comp is a heap-o-crap.

Thanks again for all the feedback it is very helpful!!
 

_JOE_

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May 10, 2007
4,697
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Your local Suzuki parts dealer might be a good place to try? Any shop that works on bikes/quads will have at least a small selection. Some may even let you swap them out for tuning.....
 

_JOE_

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May 10, 2007
4,697
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Your local Suzuki parts dealer might be a good place to try? Any shop that works on bikes/quads will have at least a small selection.
 

2strokerfun

Member
May 19, 2006
1,500
1
StreetLimitz89 said:
., but i decided to run with a .080 over bore and that is a 1.0mm bigger bore, ...

That would be a 2.0mm overbore. Each 0.020 roughly correlates with a 0.5 mm

And 2mm is more likely to require rejetting than 0.020. With 0.020, sometimes you have to rejet and sometimes you don't.
 

oldguy

Always Broken
Dec 26, 1999
9,419
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We went from a 125 to 144 on my 2003 RM and we had to lean it out afterwards.
I never really paid attention during the summer because it got very little use but for ice racing we now have a 450 main and a 47.5 pilot until the temp goes below 20*F. at that temp we jump the main up to a 460.
I bought all the mains from 430 to 490 (go in jumps of 5) and pilots from 35 to 52.5 (jump 2.5) at the suzuki dealer for about $4 each

When you start jetting make sure you have a new plug and a clean/oiled air filter or you will be wasting your time. also be sure to keep track of changes and what they do at certain temps and humidity. I tend to forget details so I write down the specs each time we ride, then next winter we will have a solid starting point
 

rm1125er01

Member
Jun 16, 2010
14
0
So I got a call today from the machine shop that I stopes off the jug at to get bored and he had bad news. Basically I need to re-plate or re-sleeve..... I'm leanin more towards the re-sleeve but I was wondering what you guys had to say about it
Thanks!
 

julien_d

Member
Oct 28, 2008
1,788
0
re-plate
re-plate
and
re-plate

What does EG charge for a re-plate anyway? Using Millennium?


As for jets, I like jets r us pretty good. Or pats small engine. Both offer genuine keihin or mikuni jets.

J.
 

whenfoxforks-ruled

Old MX Racer
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Oct 19, 2006
8,129
2
Merrillville,Indiana
I have not called Eric in a while. It costs what ever? And he gets quality parts, for about as good a price as any. Unless you get a killer discount, like half off? As soon as my suspenders get fixed, then I will have an up to date price!
 

whenfoxforks-ruled

Old MX Racer
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Oct 19, 2006
8,129
2
Merrillville,Indiana
I could lie, and claim the drooping pants was me being a tool? No way, and sagging britches is dangerous! Not to mention the gay overtones!!!! No, I am having the Huck valve installed, some valving and springs, (new plating on the shock shaft Julien is $125.00 or so), probably around a grand all told and done? Then, the motor. I sure hope I can drive up to see Eric, in person is always better! I have a sleeve job I want his thoughts on, it does give light to how the little cox engines work at all also. I have questions about plating sleeves? It is not real difficult to fire up a 2 stroke, but safely racing them is another story! And, jetting really is easy, as long as the rest of the bike is in order.
 

julien_d

Member
Oct 28, 2008
1,788
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I get my plating done by langcourt through a buddy that has a small shop here. I do computer work for him, he gets me parts and services at his cost (wholesale). I get a cylinder replate done for $125, $175 if it needs welding.

I think it's wise to go through someone like forward motion if you don't know what to look for when you get the cylinder back. Port chamfer, cleaning, etc. This way you get an experienced set of eyes on it before it comes back to you. Also, if you plan on having porting done or something, obviously it would be good to let them handle the re-plating as well.

If you're comfortable going over the thing yourself when you get it back, you might save a few bucks going straight to the company doing the re-plating?

Have heard of plating sleeves before. I think it'd be worth it for the longevity, but I can't imagine it would help with the basic issues a sleeve introduces. Heat dissipation, port alignment, etc.
 

whenfoxforks-ruled

Old MX Racer
~SPONSOR~
Oct 19, 2006
8,129
2
Merrillville,Indiana
I have no idea who MX Tech uses to replate the shock shafts. Bet its somehow different than cylinders? He sold me on better seal wear and less drag. When you get a jug back from Eric, it gets a porting once over just to clean up the process. I would rather he see the job through, before a factory worker. He may do a trade off with Millennium and once over all their jugs for free plating? Its not port modding as much as the proper balance and texture. Thats why I leave it to him, and I know I am getting quality parts.
 
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