Is anyone running the hmf exhaust for the 850 yet?If so how do you like it and can you tell a differance in power?

 

Last I heard a few days ago is that HMF is claiming the XP needs a tuner and will run lean without one. Thing is the tuners aren't available yet,they were saying 2 weeks. Some people,including my dealer are skeptical and speculate that the tuner probably isn't needed as Polaris' generally run on the rich side. Maybe the XP is set up leaner that past machines though? There is a guy on HL who says he is going to put one on and have the AFR checked without the tuner. Hopefully that will give us an idea of whether or not we need to spend almost $300 on a tuner just to add the exhaust.

 

Yeah most of them dont need a tuner with just a slip on exhaust, i would like to hear one on a machine being ridden not just the sound clip hmf has.I like the xl the best.

 

It appears that the XP has very little room for dual exhaust, but It would look awesome with dual silencers back there, like the Sportsman 800 has

 

HIGHOCTANE i see on another forum that you got your exhaust,can you post some pics and a sound clip of it being ridden please also did you check to see if it will need the tuner?

 

I will post up a vid and some pics sometime today. I talked to HMF about the tuner,still not available yet. And while they wouldn't say it wasn't needed,they did say "the fueling is close without it". But that "i should eventually get the tuner".
So imo the air fuel ratio must not be that bad.
My dealer has one on their shop XP,with no tuner,and they don't seem concerned that it is lean. And they mod alot of machines as they race ATVs. But I plan to read the plugs today just for piece of mind.
With all of that said,the choice to run it without a tuner is one each individual must make for themselves and in any case I think you should get the AFR checked or at a minimum read the plugs if you know how(not being funny,it isn't as easy as some think).
I did find it interesting that I can not find it in writing anywhere that a tuner is needed. Nither on HMF's website or the paperwork with the exhaust. If it was that important wouldn't there be a warning statement?

 

Here is a short clip:

I have more video,but anything longer takes forever to upload.
Disregard my daughter yelling in the background,lol.

http://s95.photobucket.com/alb...ew&current=Produce.flv

 

Thanks for the video i like the sound of it, how was the installation and can you tell a differance on the power?Sorry for all the ? Also does it come with a spark arrester.

 

Install wasn't too bad. There are instuctions,but they leave out alot of details. Hardest part was lining up the exhaust with the mount bracket,since I was doing it myslelf I had to rig a way to hold it in position while I got the bolts started. I originally mounted the bracket first as the instuctions say to do,but then getting the bolt in that holds the exhaust to the bracket seemed impossible. So I took the bracket off the frame,bolted it to the exhaust then mounted it to the frame. Intead of using the 2 springs on the bottom,like stick, it uses a bracket that bolts to the frame and then bolts through a rubber bushing on the bottom of the exhaust. Also the heat shield needed to be adjusted to clear the bracket. Luckily the bolt holes are slotted,so that was eassy. I'll shoot some pics for you today. Obviously it still uses the 2 springs at the pipe connection.
Also you have to take off the end cap(4 bolts) and put the adaper tube in that the short elbow exit pipe clamps to. The adapter tube is a pretty tight press fit,and I guess they use a different one for the Fording pipe,if not I think it should come installed. To install it I supported the plate and used a block of wood to protect the tube and hammered it in most of the way. The last 3/8" or so it got so tight I was afraid it was going to bend the tube so I put the plate on and carefully pulled it in the rest of the way with the 4 bolts,turning each about a 1/2 turn at a time,using care to pull it up evenly. Make sure you lube it with a spray lubicant while installing it.

Yes it comes with a spark arrestor.

 

Ok thanks, i will watch for the pics and what do you think of the power differance is it noticable? Im mostly interested in throttle response and if it adds power on the bottom or mostly up high.