How do we "unplug" TTR 125 exhaust ? ? ?

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#1
I have seen several posts where people mention that they have their stock exhausts unplugged. Is there a removable restrictor in the pipe somewhere? I have put a thrust chamber on my sons bike, but if there is something else we can do to the stock pipe I would like to do it. I have also seen one persons post that says he drilled additional holes in the end cap for better flow . . . Is this a good idea? Any advice here will be greatly appreciated :)
 
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#2
What I did was remove the 3 bolts on the end cap and pulled out the spark arrester/restrictor combo. Once the part is out, you'll see that the restrictor looks like a piece of pipe with a closed end facing upstream with a spark arrester around it, all tacked to the end cap. I just hacksawed the spark arrester/restrictor off tight to the end cap and rewelded the spark arrester only back on the end cap. Cheap, easy, works well and looks like what the stocker should have been. Better than drilling holes IMO.
 

Obee

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#3
Vegas, I don't know if the bikes sold in the States are exactly the same set up as in Aus, but you might want to check the join between the header pipe and muffler. I know my 250 had a restrictor welded in there - simply a matter of grinding it out - carefully. If you can't get the muffler end cap off easily, a mate of mine drilled 4 x 1/2" holes in his muffler and it worked quite well. Doesn't look 100% though. You might also want to look at your air box as well. Is the snorkel too restrictive ??
Obee
 
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#4
Obee,

We have opened up the airbox and now we are trying to open up the exhaust as well. I will definitely go check and see if there is a restrictor between the headpipe and the silencer. Thanks for that tip! :)
 
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#5
Gardener,

That is a great idea . . . I am pulling it apart to do that today. Thanks for the reply! :)
 
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#6
holes

Drilling the holes will help and it is free.

You will feel the difference with as few as three 1/4" holes, but the more the better.

When you opened up the airbox, did you also bore out the filter cage?

Mike
 
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#7
Yes we opened up the filter cage as much as possible . . . now I think I will need to go get some new jets for it too. Reading the htreads makes me think that I should try a 110 main first. I have the end cap ready to remove the restrictor and I am going to drill some holes also . . . I figure if I mess it up too bad I will just have to buy him a new BBRpipe. :p
 

ACS

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#8
The Australian and right across the world the TTR and TTRL 125 are the same. Just some countries only get one or the other or both. The first ones were released in Japan and sold out a years production in 2-3 months and the ones we get are the second generation ones. They made minor updates to the bike when released to the world. The Yamaha Japan site has archived press releases on it. It just depends where you are when or what you got.;)

If you check out http://www.ttr125l.com under the exhaust mods there is a pic of a new end plate with a short pipe for the TTR that any small engineering /home welder can make. I did one for the TTR first off and they work well. Nice note and more zip. The BBR pipe is better but the end plate was an hour of time and a bit of welding and was a free. I used 1 1/4 OD pipe for the snout and a bit of I think 16 gauge steel and cut it out with a jig saw.
 
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#9
Obee,

If I remember correctly from seeing your other posts you have a TTR250. The TTR125 does not have the restrictor in the exhaust. The head pipe and silencer are welded together. I took the complete exhaust off and there is no restrictor plates anywhere :( Sounded like a great idea! I will definitely pass the idea on to my Brother-in-Law who has a TTR250!
 

Obee

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#10
Vegas,
Yeah thats right 01 TTR250. I initially removed the snorkel completely, but then once I got a powerpipe (Staintune), they recommended cutting the snorkel down and at angles that give more direct flow to the air filter. Also drill 2 x 1'" holes in the filter access panel, about 2" above and to the right of the centre line of the panel. This, in conjunction with the snorkel mods seems to have given enough air flow without as much water and other crap reaching the filter. If he hasn't already purchased a power pipe, tell him to lash out and spend some $. The difference in power and improved sound is well worth it. He'll have to muck around with the jetting - float postion for a while to get it right.
Obee
 
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#11
ttr 125 exhaust

i too cut open the airbox, stuck a 117.5 main in(needs a 115) pulled out the end cap cut the restrictor out as stated by Gardener, i also cut the exhaust hole totally open up to te arrestor i.d.,( if you pull it out this will be obvious), i had a stainless tip welded on the end in a turn down fashion, works great sounds good looks good and still has a functional spark arrestor!! great mod.now if i can just get rid of the top end sputter!!...cw
 
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#12
First time - On my son's TTR125 I removed the spark arrester screen then removed the exhaust snorkel and enlarged the resulting exhaust flange opening to about 1.25 inches and then rewelded the spark arrester screen to flange. It made an improvement but was loud.

Second and current mod to exhaust tip - installed a short section of pipe much like the original snorkel (with a projection into the exhaust chamber canister of approximately 3/4 inch). The new snorkel has an internal diameter of approximately 1.1 inches verses the orignal 0.8 inch diameter. Reinstalled the spark arrester screen. Result is better seat of the pants torque, acceleration, and its also quieter.