Pipe and CoreII problems

[Dingoe]

Long, but any input would be a major help.

Bike XC300 2001

I’m having problems getting my FMF Gnarly and new Turbinecore II to lineup. In order to get the core II to lineup with the brackets on the subframe, the head of the pipe is pushed forward off of the Exhaust Spigot. The Exhaust spigot has two O-rings and the pipe is not flush over the inter most O-ring. I could see the O-ring, I used some of the cooper gasket sealer to bridge the gap, but I’m wondering if this is okay or will it cause the bike to run flat due to possible leakage. In order to get the core II to lineup at all, I hade to take a hammer to it a bit and it took 3 of us pulling, pushing, and bending to bolt it up. The old core II fits with no problem, but it’s a shell only and I’ll have to pirate the internals to use that one. The new Core II is for the 99-02 years and should fit, but it has a slight rounding of the snorkel canister union, where the old one was flat.

I’ve owned KTM’s, Huskys, and Yamaha and never have I had a bike give me such a fit. Last night I had to grind down the petcock valve to get it to work with the IMS tank. I could get the tank on, but once in place with the shrouds the valve was up against the jug so tight I couldn’t turn on the fuel. The new plastics had to be modified (cut and ground) to bolt up and the Guts seat cover, don’t get me started I was ready to trash it and go buy a KTM or Moose cover (looks like it will fit).

I’ve finally got the bike together (took two days, I’ve never had that with any other), less the front wheel (truing now) and I just hope I can run it with the gap at the pipe. If not back to it and I’ll cannibalize the new Core II to rebuilt the old one. Go figure FMF wouldn’t sell me a replacement internal Turbine unit, they would only sell complete silencers.


Thanks for any input I should have it running today with luck.

 

[gasgasman]

Your pipe may be bent.
Mine was the same way you described. The bike would make a funny whistling sound on accel.
I went to the DOMA pipe because the FMFs are so ill fitting,even when new.

 

[jeffd]

I recall that they changed the design on the gnarley or the silencer in the 2001-ish timeframe. Depending on which ones you got - it might require that you cut the stinger on the gnarley to get proper fitment. I don't recall the specific amount - but it wasn't much - I think it was 3/4 of an inch, but I am not sure; I am fairly sure I had to do this to my 2001 gnarley to get the turbine core II to fit right.

jeff

 

[Brian VT]

The bike would make a funny whistling sound on accel.

Like a CRE ? They have the most unique sound. I kinda like it.

 

[Dingoe]

I guess I got fixed in a rut, because I never though about cutting the end of the gnarly. That sounds like such a easy and quick fix. I’ll look at that this coming weekend and high-temp cooper sealer, some hose and claps and the silencer to pipe junction will work even if I cut it too short.

I can afford much more especially a new pipe, so cutting sounds like a quick option.

Thanks

 

[jeffd]

You should be able to slide the silencer on - then see how far back the silencer is fitting. Then trim by this amount. I don't think you want to be put in a position where you have to use hose clamps, etc. I think it would be better to have this junction a little more flexible, etc. I use zip ties to hold the plastic/nylon thingy that goes on the pipe to silencer junction to keep it in place.

jeff

 

[MattR]

Did you change the pipe too or just the silencer? When I put a new gnarly pipe on, the fit was different than the original one. I think the engine was shifted slightly in later models. My header did not fit well on the exhaust spigot. When I discounted the lower pipe mount, I got the header on the exhaust spigot better. However, this made the distance from the lower mount bracket to the frame must larger. I ended up putting a longer rubber spacer as a replacement bracket.

Could you make up different hangers for the silencer? Either another bracket or ovalize the current holes. Depends on how offset it is though.

 

[Dingoe]

Only the CoreII was new, but it was just a bit longer so I cut approx. 20mm off the pipe and it all mounted up really well. I ended up using Permatex cooper sealer on everything, but that’s habit with all our 2-strokes to reduce oil dripping on other parts.
It should work very well now. On the motor shift, I was told that the 2003 frames changed slightly and the motor placement was improved and the FMF parts better.

Thanks for the input.

 

[Dave Perna]

FMF Gnarly for 2006

Geez, I was thinking about getting an Gnarly for my 06-300EC. Has FMF fixed these issues or are they still ill fitting. Oh did you have to change the jetting for the FMF.