get a GREAT sounding exhaust for your bike easily...

[bogieboy]

**MODS this thread is currently a work in progress, i will edit it to have pics of everything i can possibly get now that i installed the silencer. i intend this to become a How-To thread once it is finished**

well, i picked up a FMF powercore2 for a ktm 96 250,and did a bit ofmodding to make it fit my Shineray/rocketa DB07a style lifanoid, and i am very happy with the results...

to install the new silencer theres a few things you will need.

the new silencer
Tiger Patch
a cutting tool such as a cut off wheel or a hacksaw or bandsaw
1- inch and a half or 38mm exhaust clamp
basic wrenches for removal and installation of the exhaust

botht e tiger patch and the exhaust clamp are readily available at your local parts store

step one, find a pipe for a Ktm 250 smoker (i got a powercore, i would assume a turbine core, quietcore, etc would all be relatively the same, just how loud or quiet it will be) the powercore2 part # is FMF # 025025

step 2, cut the lead pipe off just after the bend, all you need is the straight piece, you dont need the bend. i used an air cutt off tool, a hacksaw or angle grinder would also do the trick, or if you got fancy tools like a metal cutting bandsaw that works too...



step 3 cut just the stock muffler off the stock leadpipe. mine had a cone shape thing leading into the muffler, i cut it off right before the cone thing, (sorry i forgot to get pics, will edit them in later) so the lead pipe was as long as it could be and still be the uniform diameter.
step 4, cut 4 1/2-1" slots in the factory pipe, so it can crush down easier on the new pipe.

step 5 put the stock leadpipe back on the bike, sans muffler

step 6 test fit the new silencer in the slip fit you created in step 4, and test mount the silencer, the front mount on the silencer should match up with the stock muffler mount.

step 7 remove the silencer, and place a few wraps of Tiger Tape around the new silencers leadpipe end. this will create a gasket seal with the stock leadpipe,and not require any welding.

step 8 place the exhaust clamp on the stock lead pipe and slip the now tiger patch wrapped lead pipe back in.

step 9 attach the silencer to the stock exhaust mount. tighten down the exhaust clamp

step 10...enjoy the new beefy sound of your China Bike (and rejet the carb as needed...it will need it...)



and for comparison to the stock, i had a bit of a leak, but you get the idea.... it sounds like a stinking scooter....

[Weldangrind]

Much better, indeed! I'd start with two sizes up on each jet.

[SpudRider]

Good job, BB! Thanks for taking the time to document your work.

Your muffler sounds great! Even more important, I'm betting you will get more performance from your engine with the aftermarket muffler.

Incidentally, you bike looks very good in Yamaha Blue.

[bogieboy]

Originally Posted by Weldangrind

Much better, indeed! I'd start with two sizes up on each jet.

thats about what i had figured as well... anyone know what type of jets the carb takes on the lifanoids? are they mikuni?

Originally Posted by SpudRider

Good job, BB! Thanks for taking the time to document your work.

Your muffler sounds great! Even more important, I'm betting you will get more performance from your engine with the aftermarket muffler.

Incidentally, you bike looks very good in Yamaha Blue.

thanks for the kind words spud, even if i dont get more performance from the bike, i shed litteraly 20# just by cutting that stock can off... that can is a PIG... the new muffler weighs MAYBE 5 pounds, probably closer to 3... it does have a bit of a spark arrestor in it, but itsno way approved by USFS...LOLits about 8 pieces of wire in a random pattern across the outlet of the can... other than that its a stright thru performance muffler...LOL its considerably quieter than a straight pipe though, so thats good, i was worried about it being REALLY loud...its not, just beefy...LOL

and i am a big fan of blue...i am very tempted to shoot all the white with flat black krylon fusion though... just something i like about flat black and gloss blue...LOL

[Weldangrind]

I'm with you on the black and blue scheme; that's how my TW ended up.

Your carb is probably a Keihin clone, vs. a Mikuni, and Mikuni clones can be difficult to find replacement jets for. Count the number of screws on the float bowl; 4=Mikuni and 3=Keihin.

Here's a Mikuni that would do the trick and be more easily jetted: http://www.ebay.com/itm/Carburetor-C...4979d6&vxp=mtr You'll easily find jets online or at your local Yamaha dealer.

[bogieboy]

Originally Posted by Weldangrind

I'm with you on the black and blue scheme; that's how my TW ended up.

Your carb is probably a Keihin clone, vs. a Mikuni, and Mikuni clones can be difficult to find replacement jets for. Count the number of screws on the float bowl; 4=Mikuni and 3=Keihin.

Here's a Mikuni that would do the trick and be more easily jetted: http://www.ebay.com/itm/Carburetor-C...4979d6&vxp=mtr You'll easily find jets online or at your local Yamaha dealer.

thanks for the link, i will probably pick one up... one could stand to reason going up to the 30 mm may already be jetted pretty close, since my bike has a 27mm on it now... gotta go get a few spark plugs and do some plug chop tuning now...LOL or pull the wide band O2 sensor out of my truck... thats an indispensable tuning tool.... love it...too bad its a permanent install type one...

[Weldangrind]

Wide band only works if the testing instrument doesn't just zero in on one Lambda. These engines seem to make more power with a fatter mixture, and my guess would be 12.5:1 on the top end. What do you use as a testing instrument?

Also, bumping to a 30mm means even more air and less fuel, so the Mikuni would need to be jetted out of the box. I recommend 112 main and 27 slow (if you're under 1000 feet) to start. It comes with a 100 and 20, which is dangerously lean with a free-flowing muffler.

[bogieboy]

Originally Posted by Weldangrind

Wide band only works if the testing instrument doesn't just zero in on one Lambda. These engines seem to make more power with a fatter mixture, and my guess would be 12.5:1 on the top end. What do you use as a testing instrument?

Also, bumping to a 30mm means even more air and less fuel, so the Mikuni would need to be jetted out of the box. I recommend 112 main and 27 slow (if you're under 1000 feet) to start. It comes with a 100 and 20, which is dangerously lean with a free-flowing muffler.

my wideband is an AEM uego, it will read from 9:1 a/f all the way to 20;1, and my truck is happiest at 13:1 WOT now that my supercharger is gone, back with the blower (sold it for funding a turbo build with a forged engine and lots of fun goodies..LOL) it ran its best power at 11.5:1, and on the street i ran it a hair fatter than that to quench detonation under the tq curve...

thanks for the jetting reccomendations as well

[Weldangrind]

I'm amazed that max power was that fat! Even carb'd strip cars don't normally run below 12:0, and that's getting close to E85 territory. I bet that AEM Uego is a fun toy. It would be interesting (to me) to weld an O2 bung on the header pipe of a China bike and really learn what it likes.

What would be even more interesting (again, to me) would be to use the Bosch wideband with a data logger on a smart phone. You could watch the O2 needs throughout the RPM range, and figure out what it wants at cruise RPM.

[bogieboy]

the reason it made max power that fat was because i could add in more timing, and used the extra fuel to cool the chamber to prevent detonation, instead of retarding the timing to prevent det... Its a really fine line...LOL and that was running 93 octane, if i had run 100 or 106 i could have put a bunch more timing back in and made more juice yet...but 7.50 a gallon for a daily driver is a no-no....LOL

[bogieboy]

Also gotta remember boosted vehicles are gonna run fatter because of the detonation quench that i described... Some boost cars are happiest at almost 10:1, but they arent able to be daily driven unless you change the oil every 500miles due to all the fuel washing down the cylinders and thinning the oil...

[bogieboy]

Oh and.....LOL i made 255hp/312tq at the rear wheels, which calculated to roughly 320crank hp and 390tq on an otherwise stock 318 v8 dakota...hehehe

[Weldangrind]

More than 1hp per CI at the crank! I forgot about the fuel needs of a boosted engine; I was thinking about NA.

[Ariel Red Hunter]

In commenting on your second paragraph, yes, 30mm can cause carburation woes on 250's. I had a new AJS Model 14 CSR That was faster (Just over 80 mph) than these bikes are, running an Amal 1 1/8th choke carburetor. That's about 28.4 mm. Putting a 1 3/16 Amal TT carburetor on it made it very fussy. A 1 3/16 Amal is 30.1625 mm. You had to lead the engine by rolling in more and more throttle to get the best out of it. The Model 14 engine is surprisingly similar to the engine in the Hawk, except it had twice the oil capacity, and was dry sump. It was only 2 or three mph slower than the short stroke AJS Model 16 350, and faster than the long stroke Model 16 350. The little Model 14 CSR benched at about 21-22 hp at the crank. 15 cubic inches.

Originally Posted by Weldangrind

Wide band only works if the testing instrument doesn't just zero in on one Lambda. These engines seem to make more power with a fatter mixture, and my guess would be 12.5:1 on the top end. What do you use as a testing instrument?

Also, bumping to a 30mm means even more air and less fuel, so the Mikuni would need to be jetted out of the box. I recommend 112 main and 27 slow (if you're under 1000 feet) to start. It comes with a 100 and 20, which is dangerously lean with a free-flowing muffler.

[bogieboy]

the mikuni that we commony refer to as a 30 mm is really a 26mm across the throat, but is commonly referred to incorrectly as 30 because its a 30mm bore behind the venturi...LOL