Top end 07 m8.

[Donthatethem8]

So I bought an older m8 that has 6k miles on the odometer, engine has never been apart. Older guy I bought it from said his wife and daughter rode it. I definitely believe that because of how good of shape the body is. I rode it last season and I feel like I wasn't getting the track speed that I should be getting and I want to wake it up. So I have a new wiesco top end for it. But I also was looking into rk-tech cylinder porting. Should I do both at the same time is that recommend? And I wanted to see if anyone else has delt with them and can vouch for the claimed results on thier website.

 

[summ8rmk]

If u get 40mph track speed 6k- 7k ft from a stock 07 that is good.
Remember, the 07 ran way to rich from the factory and has the big bulky reverse diamond drive.
They will never perform the same as the 09 and newer M's.

GS6

 

[Donthatethem8]

I did think she was rich... plugs indicated that. The highest track speed I would normally get in the light stuff was 37ish and I don't feel like that was enough. My riding buddies have upgraded, and I'm still in school so I'm just trying to keep up.

 

[summ8rmk]

An SLP pipe kit will do wonders for that sled. I bet u can find a used set on this site. A fuel pressure regulator may be needed also. Some M's had to high of pressure from the stock system.
I liked the straight 36° helix and MDS weights with the SLP pipe on my 09. 45-48 mph track speed with 153x 2.25 powerclaw @ 6-7k ft.

GS6

 

[89sandman]

I rode a highly modded 07 for 4 years. If you want to have the cylinders ported now is the time, while you have the top end off I'd do the oil pump delete also. There are so many things you can do to this sled but how much money do you want to put into it? I'd do the top end with the porting, full pipe kit, clutching with fuel controller. The stock boards are horrible so some inserts and update the tunnel to the 09 style. Just hard to dump a bunch of money into an old sled when you could be just riding it as is and saving that coin for something newer. No matter what mods you do you're going to have a tough time keeping up with your buds on newer sleds. Not impossible but you are going to have to work a whole lot harder.

 

[Donthatethem8]

Thanks for the replies. Yes it is hard justifying spending big money on an old sled but I think I can get the performance that I'm looking for without spending too much. Rk-tech says that there is no need for a fuel controller with just the porting. Would it be required if I were to also add a pipe?

 

[89sandman]

If you do the pipe and porting I would most definitely run a fuel controller.

 

[Donthatethem8]

Okay thanks. I supose I'll call rk-tech and see if they can get my jugs in. I hope they can being this is the season for working on sleds. And yeah the newer sleds are hard to keep up with. I'm just waiting it out untill I can get myself a newer one. But for now I really like the way the m series has treated me so far, a few more ponies and I will be very happy.

 

[summ8rmk]

On the 07-09 800 u can run either the SLP pipe OR the RKT head (not sure if thats with porting)without a controller but from everyone i have talked to, u need the controller when u combine the 2.

I don't know which mod will net the most gain(both say 15hp). The 07-09 really need the porting to get the engine to respond like the HO.

I have not ridden a ported sled but my 09 was good with the pipe.



GS6

 

[knifedge]

maybe the engine was fine , just the clutch springs were sacked out

 

[mountaincat 800]

If interested I have a used full SLP pipe set that came off an '07 M8 I would sell for $250.
PM if interested.

 

[Donthatethem8]

I think I'll go with the porting for now and see where I am on fuel controller. Thank you very much Mountian cat, but I don't think pipe and porting is in my budget at the moment. Sounds like a reasonable price for someone looking. I would rather not have to spend the extra on the fuel controller that would be needed. As for the clutching I put a brand new primary last season. However my secondary does need some attention I have some flat spots on rollers. Who makes a rebuild kit for thoes or did o have to buy a whole new one?

 

[summ8rmk]

Buy rock rollers they are inexpensive

GS6

 

[summ8rmk]

I would take mountain cat's offer. That's a good deal on a pipe and top end power will be better than what the porting provides. Also, when u sell the sled, put the stock exhaust back on and sell the pipe for $250 again. Free HP for a year or 2.

GS6

 

[kiliki]

stock pistons, slp full pipe and a 2010-11 head and rip the piss out of it.

 

[Donthatethem8]

If I didn't do any porting work and just put the pipe and a HO head would at that point would I need a fuel controller? I really want to stay away from that option because when you start talking fuel controller I would want to know my a/f ratios and egts and thoes gauges are not cheap. Anyway it all depends on price at this point I will explore my options and I'll see what I come up with.

 

[kiliki]

your best bang for the buck is just do the full pipe set. no controller needed you can do the head with the pipe but you will be on the edge of a fuel controller.
porting will run you more than just the pipe fyi.

 

[CATSLEDMAN1]

m ate

I see you ride in the Big horns, been there with my old M8,biggest climbing improvement to that sled was gearing it like the 2010, orange secondary spring, 2005 spring tension adjustable 36 helix with about 12mm plastic nut in from face of face plate, power claw track of any kind, you can easily pull 40 mph track speed with a track moving more snow. That motor might be fat, some where but not all, your taking out the piston so check piston wash, if its smallish and less than 10mm, be careful on mods that will give you a lean weak running engine that will end introuble.

Mod the hood air plenum and cover the hot air holes, clean cold air is best, if you ride powder make more cold air intakes around speedo and frogskinz them............that will also overall lean the engine running.

MDS weights is the next place to spend money.