Jump to content
Sign in to follow this  

04 TTR-125 Bottom End Torque;

Recommended Posts

This is my Son's bike. 

 

I have changed the pilot jet from the #15 to #17.5, which only helped on the "long" warm up process and did not any bottom end torque.

 

To me the TTR 125 is a revver, which is somewhat shocking.

 

It is almost dimensionally exact to the XR200R, except ~ 37% smaller in cc's.

 

It has the some bore x stroke ratio and the same compression ratio.

 

My XR200 has ample torque and can be a revver as well even with the stock exhaust. 

 

From my perspective it has more in common with the YZF line vs. the TTR line. 

 

If I undo the airbox lid and perhaps put on a power tip, will this give it any additional bottom end torque ???

 

Is this just cammed to be a revver ???

 

Many Thanks in Advance !!!

 

Michael 

Share this post


Link to post
Share on other sites

What's the past history of this bike?

Who had it, and what was or wasn't done to it?

 

No, a TTR125 ain't a revver.

In my opinion, it has similar power characteristics as an XR-200R, just less everywhere because of the obvious displacement difference.

That is:

It's just the opposite of a YZ - quiet and mild with very old-fashioned 4-stroke dirt bike kind of power, just like back in the olden days.

 

I'd measure the valve clearances and make sure they are in spec.

They are the old-fashioned screw-and-locknut type of adjustment, so there's no excuse not to check.

 

I'd service the air filter.

Often, just as with any other dirt bike.

 

I'd change the main jet to a 107.5 or a 110, which ever runs better for you.

This is assuming the carburetor isn't plugged-up to start with.

The fuel screw on my TTR125LE is set at 1.5 turns out.

 

The stock airbox and air filter and air filter cage are pretty restrictive in order to cut all of that harmful-to-the-environment intake noise so none of the trees or tweeting birdies get scared out of their habitat permanently.

Same for the muffler.

On the previous 4 TTR125Ls I've owned and ridden, I uncorked the bike with the above mentioned carburetor jetting, aftermarket exhaust (Yamaha's GYT-R was what I used back in 2003), and the BBR Hi-Flow Air Filter with a big hole cut in the airbox top.

On the 2013 model I currently have, I decided to keep the stock muffler due to consideration for my neighbors (who are now in their mid-70s in age), but did the rest of the mods mentioned above.

The bike has as much bottom end torque as I can expect a 125cc 4-stroke to have without a big-bore kit.

Edited by YZEtc

Share this post


Link to post
Share on other sites

No particular history other than modification upgrading to the #17.5 pilot. It does not smoke and is easy to start, estart, or kick.

I had read that the #15 pilot made it so it took forever and a day to warm up, which I found to be true, so I changed to a #17.5 pilot, warm uptook about 1 to 2 minutes, vs. 4 to 6 minutes. Fuel screw is set at 1.5, so good there. Air Filter is clean and fine.

I was thinking perhaps the stock exhaust was so restrictive that perhaps this was the reason for the revvy power, vs. torque feeling it has to me. It has a very linear power delivery from bottom to top, however it is weak to me. I have set up friends XR100R's that seemed to have more torque than the TTR 125, just not as much horsepower, hence my question is it cammed that way.

At this point, I would disagree with the smaller version of an XR200R when it comes to torque. I can ride my XR200R like a trials bike, or I can torque up a long hill, with slight clutch slip and it also can be revved out. The XR200R is anything else but a torque monster, or a horsepower king, it just puts all of it's power to the ground. I was hoping for the smaller version for my son.

I guess the next thing for me to do is take out the baffle to see if it gives me the torque I think the bike is missing and or open the air box. The #110 main may be in order as well, but that has nothing to do with bottom end torque I am seeking, but still might help in the top end.

I can't see anyone endorsing the power tip, but then again, it's hard to isolate both together in the search engine, because it searches for both, "power" and "tip", instead of "power tip".

Thanks for help !!!

Michael

Share this post


Link to post
Share on other sites

OK so I took the intake screen out, this TTR came with a K&N filter, so serviced, which was not to bad. 

 

I drilled 6 holes with a 1/8th drill bit in the baffle plate.

 

Originally was getting best performance with the #17.5 at 1 turn out, I am now at 1.5, so seems to have worked. 

 

I think the lack of torque I am feeling is the "huge" flywheel weight.

 

Still on the fence to remove 22oz's from flywheel.

 

I think that is the difference of the XR100 vs. the TTR125, 

 

My 15 year old is on the short side wants to move up to my spare XR200R and my youngest on a TTR90 wants to make the move the TTR125. 

 

Youngest struggles with the whole transmission gears and gear selection, so I might be in the market for an auto clutch which Rekluse has discontinued. 

 

Michael 

Edited by KTM520EXC

Share this post


Link to post
Share on other sites

Try lowering the gearing with a 12-tooth front sprocket if you want quicker acceleration.

Sprocket Specialists sells them.

It's what I've done to all 5 of the TT-R125Ls I've owned over the years because I ride them on my wooded 2-acre lot and it's tight.

Share this post


Link to post
Share on other sites

YZEtc,

 

Did you ever remove any weight from the flywheel on any of your TTR125's, if so, your thoughts ???

 

Thx !!!

 

Michael 

Share this post


Link to post
Share on other sites

Negative.

For the riding I do with mine (threading through the stick trees on the side of a hill on my lot), the power characteristics are good as is.

Just remember while a lighter flywheel will accelerate quicker, it also decelerated more easily, as in stomping on the rear brake pedal without pulling the clutch lever in.

 

How did the valve clearances check turn out?

Edited by YZEtc

Share this post


Link to post
Share on other sites

YZEtc,

 

Did not check the valves, seems to run fine as is.

 

I always knew something was wrong with clearances when the bike was difficult to start, due to the the valves clearances tightening up. 

 

Bike starts fine.

 

Gotcha on the flywheel, double edged sword. 

 

Thanks !!!

 

Michael 

Share this post


Link to post
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:

Sign in to follow this  

×