Jump to content

Top 5 things you would do to a 05 yz125 for motocross


Recommended Posts

I had a different thought.

Being its a 2005 yz 125 in a class filled with 4 strokes, you are going in down on power. I believe I might keep the bike in perfect condition and work on being the best rider you can be. If that means riding courses with the money, so be it.

Mods for the bike are much more fun, and the direction I went, but in the long run a mod adding .35 horsepower probably does nto matter as much as a good rider who can shave seconds from a lap time.

Link to comment
Share on other sites

Suspension is number one, then depending on how much money you have or what you want send the motor out to a professional engine builder like Eric Gorr and have him work his magic getting the engine how you want it. You'd be amazed what they can do with these things. Alot of people called the 02+ CR125s garbage and in stock form I'd agree but after riding one of Eric Gorrs engines I seriously considered buying one just to have the chance to ride it every time I go out.

Link to comment
Share on other sites

I had a different thought.

Being its a 2005 yz 125 in a class filled with 4 strokes, you are going in down on power. I believe I might keep the bike in perfect condition and work on being the best rider you can be. If that means riding courses with the money, so be it.

Mods for the bike are much more fun, and the direction I went, but in the long run a mod adding .35 horsepower probably does nto matter as much as a good rider who can shave seconds from a lap time.

👍 I was going to post the same thing. Hard to beat a good rider no matter what he is on.

Link to comment
Share on other sites

If you haven't already, replace the shift stopper on that '05. My '06 is sitting with the cases split because of said shift stopper.

Like some have said above, suspension first, nice crisp carb. tuning, keep the engine fresh.

Link to comment
Share on other sites

If you haven't already, replace the shift stopper on that '05. My '06 is sitting with the cases split because of said shift stopper.

Like some have said above, suspension first, nice crisp carb. tuning, keep the engine fresh.

So why did you split the cases to change your shift stopper? All you had to do was take the clutch basket out!!

Link to comment
Share on other sites

Sorry, I didn't clarify. Two broken clutch push rods and you have to split cases to find the problem. The problem was that the outer race and bearings from the shift stopper damaged the counter shaft bearing on the opposite side, putting stress on the push rod.

Link to comment
Share on other sites

Well here is what I have done on my 05 yz125 (most done when I bought it)

Renthal Bars

Asv Levers (life saver)

Fresh Top end (please do it)

Updated shift stopper (please do it)

Renthal Sprocket/did gold chain

Race tech suspension

Pro Circuit pipe/exhaust

Just got new tires today

I would say suspension is the best thing (top end and shift stopper for maintenance not performance)

Next is the right tires

and then maybe a pipe/exhaust for the type of power you want.

Just ride the crap out of it and get used to riding a 2 stroke pinned, I ride mx recreationally and this is the best thing you can do. You dont need any engine mods necessarily yet, even on suspension I would wait if its your first time riding a big bike and if you think itll take time for you to adapt. That way youll suspension will be done for your intermediate or fast riding.

I made the same switch as you (4stoke trail bike to 125) its a way different bike so it will take time to adapt. This is assuming your previous bike was the crf150 thats in your signature.

Link to comment
Share on other sites

Well here is what I have done on my 05 yz125 (most done when I bought it)

Renthal Bars

Asv Levers (life saver)

Fresh Top end (please do it)

Updated shift stopper (please do it)

Renthal Sprocket/did gold chain

Race tech suspension

Pro Circuit pipe/exhaust

Just got new tires today

I would say suspension is the best thing (top end and shift stopper for maintenance not performance)

Next is the right tires

and then maybe a pipe/exhaust for the type of power you want.

Just ride the crap out of it and get used to riding a 2 stroke pinned, I ride mx recreationally and this is the best thing you can do. You dont need any engine mods necessarily yet, even on suspension I would wait if its your first time riding a big bike and if you think itll take time for you to adapt. That way youll suspension will be done for your intermediate or fast riding.

I made the same switch as you (4stoke trail bike to 125) its a way different bike so it will take time to adapt. This is assuming your previous bike was the crf150 thats in your signature.

Thanks for all the good info everyone. yes i did ride a crf150f, and got the 125 a few weeks ago. took it to the track and did great i love it. When should i do a top end? i did a compression test and got 144, then i did a compression test WOT and got 148? also can someone send me a link or explain how to replace the shift stopper? and what parts to order. thanks everyone 👍

Link to comment
Share on other sites

Thanks for all the good info everyone. yes i did ride a crf150f, and got the 125 a few weeks ago. took it to the track and did great i love it. When should i do a top end? i did a compression test and got 144, then i did a compression test WOT and got 148? also can someone send me a link or explain how to replace the shift stopper? and what parts to order. thanks everyone 👍

Just search shift stopper, but all you need is the updated shift stopper (automatically updated so just order a new one and theyll give you the 07 part), then the clutch cover gasket. This will require you to remove the clutch basket. Your compression looks good but I always like to replace a piston on a used bike. I would put in a good forged piston over the stock cast piston, I recommend wiseco. Theres some discussion over oem pistons or wiseco, but I run a wiseco (just make sure you warm your bike up properly or else it will cold seize if you just hop on and go wfo). Have fun on the 125! I know I love mine!🤣

Link to comment
Share on other sites

  • 2 weeks later...

When my son was on 125s the biggest things we did to improve the overall performance of the bike were.

1= Suspention,We had FTI do the suspention and it made an awsome bike even better.

2= Pipe, we installed a Pro Cuircut pipe and silencer and that not only made more power but it was a much better power.

Thats all we did to our 125s and they were awsome. My son always said that after the pipe and suspention he didnt want me to touch the bike.

PM me if you want I still have the pipe.

John

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

×
×
  • Create New...