Hey Alky, repacking on a two stroke might make performance diff because most of the power on a 2 stroke comes from the exhaust, but on a 4 stroke we got valves to take cake of all that, so the faster we can get the exhaust out the better, we only need a very minimal amount of back pressure. A 4 stroke will run better without packing.

So Pinhead loose the packing!!!!!

 

That's not actually true. Four strokes, while using valves rather than a pressure bottle exhaust, still need a fair amount of back pressure to slow the rate at which exhaust leaves the combustion chamber. A loss of backpressure results in loss of low end power and can even cause discoloration of the pipe due to hot gases being expelled too quickly. Pack your exhausts. They were designed to run at peak performance while packed. You only hurting yourself to neglect to do so. If you don't wish to repack to often, seek out a pipe (such as HMF) which uses a ceramic packing or simply replace your packing with ceramic; it can be bought through any major distributor.

~HoundDog

 

Just Remember that the companies that make the pipes make $ on the repacking kits for the pipes too. Would it hurt anything if you changed the oil in your car every 100 miles instead fo 3k? No, but i bet jiffy lube would love it! LOL... I'd say after 50 hours inspect your packing and, see how beat up it is. if it is blowing out the pipe and, clogging your sparkarrestor or, is completely burnt and, hard like cement definitly replace it!

Also the difference in your tuning and, your type of engine will make a difference as well. If your running a 2 stroke which burns oil and, gas you get your packing caked up and, blown out more quickly. Also running rich on a 4 stroke can make your packing crap out quicker since your not burning all the fuel as quickly and, it deposits in the packing on the way out.

Lastly, along with easy packing replacement i'd recommend a pipe with options like a quiet core insert for noise restriction areas.. These are all things to consider in a pipe!

Even thought there may be slightly better flowing pipes out there = I went w/ a Biggun because it was nice looking from head pipe to silencer, had a quiet core option (which i needed for the dunes) had Cermic coating which is supposed to keep the temp down and, resist discoloring, had only 4 allen screws to remove for repacking, was pretty light and, also a good bang for the buck.

 

MBRP is a quiet exhaust that doesn't require packing.

And AlkyX and Hound Dog are correct about loss of packing taking away power.

 

Pipes tune where the power is on a fourstroke too, just like on a 2 stroke, just not near as much. Besides, if you blow all the packing out you get MORE backpressure. The gasses go out into the area where the packing was, cool off, slow down, and create back pressure. Its the same thing as going from a small diameter pipe, to a huge diameter, then back to a small again. The packing is suposed to make the big diamater pipe smaller by filling in space.

 

Ward, do you have a MBRP exhaust or know someone that does? I know it is quiet, but was wondering how it performs and how much $$ they usually run. I am guessing that there is only one place to get these, that being MBRP's home web site. I am debating between this pipe or the white bros. e-series, but I have heard it is pretty loud.

 

I have an MBRP full race on my Raptor. It is quiter than Sparks and Yoshi (without the insert) and a couple of others, and makes great power. They do offer standard series that are even quiter. Mine is all stainless. The header and the silencer. As far as cost for a warrior I am not shure. I bought mine through Craycraft racing. Give Bob a call I am hure he could get you hooked up.
http://www.14mins.com/craycraft_racing.htm

My MBRP drag pipe never needs repacking either!

 

I've narrowed my search down to two, the FMF Powerline or the MBRP. Both are stainless steel, no repacking, quiet, provide low-mid range power. I'm kind of leaning towards the Powerline because it is about $70 cheaper and is still a good pipe, but my mind changes like the wind blows [img]i/expressions/face-icon-small-confused.gif[/img] All opinions are welcome, please.

 

I don't have the FMF powerline, but I have an FMF and IMO its a piece. I won't ever buy another FMF pipe again. The power, as far as Raptor pipes go, isn't very good. It leaks pretty bad and the fit could be a little better (mainly the head pipe fit is whats bad).
SCHOLLE is right about the MBRP. The standard version is pretty quiet and its all fully welded polished stainless, so very little maintance is required. You can get one from Craycraft (817) 441-5893.