FMF Fatty (Gold Series) for H series: Fitting no fun!

[firffighter]

I picked up a Fatty K-35 for my '02 220 on ebay for $25. It had a couple of nice dents, more like bashed in areas and I sent it off for repair. Cost me $11 to ship, $25 for repair and $15 to ship back. Came back in nice condition, no dents. Not too bad for under $75.

Now the fun part

Not fun trying to fit that thing! Took quite a bit of coaxing, but finally got it all bolted up. It must have been because of the previous damage because my brother runs one on his 220 and he didnt have any issues getting it on his bike.

Anyone else run this pipe? Any fit problems, or is it just me?

Oh well, guess I cant complain too much with how much I have into it.

[Indawoods]

It's not unusual to have to tweak it to fit.... It's all the weed they smoke when they make them.

[firffighter]

No kidding. I actually called them today about the fit and of course they told me that they didnt make that pipe for the KDX

After serveral "sorry dude"'s later, I basically gave up and corrected the upstanding Orange county resident telling him that he really should know the products that the company he works for produces. Oh well, cant expect much from SoCal

[radonc73]

Land of fruits and nuts!!

[barryadam]

No kidding. I actually called them today about the fit and of course they told me that they didnt make that pipe for the KDX

After serveral "sorry dude"'s later, I basically gave up and corrected the upstanding Orange county resident telling him that he really should know the products that the company he works for produces. Oh well, cant expect much from SoCal

Are you sure he's from OC - FMF is in Los Angeles County. For some of us in South Orange County, the Orange Curtain is actually at the 22 Fwy.

[firffighter]

Sorry, some of us native Oregonians are pretty hard on the land of the beautiful people

Just dont tell me you're a Laker fan and all will stay civil!

[canyncarvr]

..land of the beautiful people?



You ARE talking about Kalifornistan?


Griping at FmF about the fit of their pipes is valid..if the pipe is brand new. If it's been smushed as you indicate yours had been..why assume FmF had anything to do with it?

I've bent my pipe into a bad fit and not left a mark on it.

Get youself a couple of long steel bars. Put your 'no fit' pipe on the bike, held only with the springs. Place the silencer where it goes, note what direction the pipe needs to be bent to line up the ends. Take off the pipe, place a steel bar in each end...tweak it.

Do another mock-up..repeat 'til it 'fits'.

It doesn't take much of a bend to make a BIG difference in where the pipe stinger ends up. It may be a bit puzzling how to hold/bend/tweak/force the thing to get the stinger to move in the direction you want it to, but a bit of experimentation will get that sorted out.

[barryadam]

Sorry, some of us native Oregonians are pretty hard on the land of the beautiful people

Just dont tell me you're a Laker fan and all will stay civil!

I think them Lakerz are North of the Orange Curtain. That's the imaginary line where the earth ends. Unless I'm going riding. Or talking on the forums. You'd probably have to be living here to understand.

Seriously, you'd be amazed at how many people here have no clue what goes on just a few miles North in L.A.
My daughter went on a bus trip to San Fran while in grade school and she was pointing out her favorite riding areas N. of L.A. The rest of the kids thought they were on another planet.

[barryadam]

Get youself a couple of long steel bars. Put your 'no fit' pipe on the bike, held only with the springs. Place the silencer where it goes, note what direction the pipe needs to be bent to line up the ends. Take off the pipe, place a steel bar in each end...tweak it.

Do another mock-up..repeat 'til it 'fits'.

It doesn't take much of a bend to make a BIG difference in where the pipe stinger ends up. It may be a bit puzzling how to hold/bend/tweak/force the thing to get the stinger to move in the direction you want it to, but a bit of experimentation will get that sorted out.

Just be careful with the mounting tabs. I tried to put a bit of a Zee bend in the muffler tab for better mounting alignment, and it ended up really stressing the tab-to-pipe weld. It ended up breaking there, but that was caused by hard mounting. The break occured at the weakest point, the tab weld.

[firffighter]

Yeah, I noticed that the tabs on the pipe would be the weak point. I did a little bending with heat and cold, so I hope I didnt weeken it too much.

I put on a Moose pipe guard because they are the thickest and take a lot of punishment.

[canyncarvr]

You can be as easy as you like on those tabs...they'll still break. My last pipe had a broken top mount for years.

The Fatty was 19ga., wasn't it? It was out just before 'Burly' then 'Gnarly' I think........ (both 'names' given due to the change to 18ga. metal).

[Colorado Mike]

I bought the K-35 and K-30 , brandy new. The torque pipe was a total batch to get on, and the rev pipe fit like a glove. Not saying all revs fit right and all torques don't. Probly has more to do with which fixture they were built on.

[firffighter]

That was my brother's experience.

My PC fit like a glove as well.

Oh well. I got her on now!

[NewMexico505]

You bought a used pipe and this is more normal than most realize, not a problem of manufacture.

Then getting it repaired probably changed the component a little more.

Even taking a stock pipe off a motorcycle, it can be a bear to put it back on the same bike later. (think Harley's)

The heating and cooling cycles the exhaust goes through can change the many diameters and angles of the pipe by just a little, resulting in a pipe that needs some heavy handed tweaking to fit.

thanks for posting so others know this can be a little bit of a hassle on theirs.

-Erik

[jaydollar]

i bought a k-35 brand new for my 220 and it fit perfect with the stock silencer,the procircuit one i bought from firffighter, and my newest turbine core Q.ymmv on used stuff.j$

[barryadam]

I bought the K-35 and K-30 , brandy new. The torque pipe was a total batch to get on, and the rev pipe fit like a glove. Not saying all revs fit right and all torques don't. Probly has more to do with which fixture they were built on.

+1. Exact same experience here, both new.
Had to take off the KIPS cover to get the K-30 on, and it hits the "handle" on the RHS. The K-35 was perfect.

[r1inoz]

how much does a dented expansion chamber affect performance?

[canyncarvr]

From the DMC site:

My pipe is dented. Is it still good?

Depending on how big and where the dents are will determine how much power you'll lose. The closer they are to the cylinder, the bigger it has an effect on how the pipe makes the power. Pipe measurements are pretty precise so even a small dent can change how the pipe works. Even carbon build-up over time will effect how it works.


'It depends' is about as good an answer as you will get.


Found this:

I remember reading in a dirtbike magazine where they were dynoing a 2 stroke motocross bike (cr250) and checking the effects of dented pipes. They would take a hammer and dent the pipe in different spots to see what happens to the power, when they dented the head pipe they kept getting consistently higher horspower readings, but when they dented the expansion chamber the power would usually drop.


..only bring it up 'cuz I remember reading the same article, or at least other references TO that article.


More of 'It depends.'


Is this thread about dented pipes?

..guess I missed it.

[r1inoz]

good reply thank you for the info canyncarvr much appreciated