welds on head pipe?

[zzbudzz]

i seen someone post they grinded down some huge welds on the head pipe can some please give me a detailed describtion of this process.is this the exhaust port going in to the pipe?i have a 2002 stock 400ex just i case that helps?

[CranMan]

Where he header fits into the head, on the header itself, there's a weld on the inside that you can grind down a good bit...

[zzbudzz]

ok is it worth grinding it down (i've got a dremel tool )i would like to do this now ,i've taken the plastic off ,air box off ,chaging the oil , thinking about rejetting ,just getting a good look at my 400 while its cold as **** .( warm in garage):D Anyway how should i keep the metal shavings from falling in the exhaust port? use shop vac?new at this stuff if you chouldn't tell..:D

[big-guy]

Just finished this job like 5 min ago, Those are some huge welds. Nice, but huge.

I used a dremel with a coarse sanding drum, seemed to go faster than the grinding stones.

The welds are in the head pipe, the thing that hooks to the muffler. It should come off pretty easy, mine did. you have to kinda wrestle it around the clutch cable and oil tank, but it will come out.

I ran water through it with the hose to clean it out, won't hurt it, being stainless and all.

Also took out the spark arrester, it's falling apart!
Anyone know if say an xr 650 arrester will fit?

[zzbudzz]

i got mine off too, in process of grinding it down,need new bit for dremel tool. post back the results *bigguy* let me know how or if it improved your performance.

i grinded my header down, and removed the spark arrestor, i noticed a sweet sound, and increased trottle, pisses off neibors, but om gettin a ct pipe, and havin them rebild my 440 wit a 11;1 piston instead.

[NVR2L8]

big-guy...not sure if a XR650 end cap would fit on the stock 400EX silencer...kinda doubt it. But, I do know that the end cap from a 250EX will bolt on, and the tube inside the chrome outlet is slightly larger too. The downside of the 250EX end cap is that it's around $50 from Servicehonda.com.

i am pretty sure the xr650 one will work. i know dirt wheels did a xr600 one and i belive the switch the end cap from a xr 400 on there cause it was a large diameter.

[fourplay]

I took the welds out today. It wasnt worth the effort to me. Just my opinion::(