maverick
Extreme
Took out my 07 Apex Mtn after installing an Excell under-tunnel exhaust, in some nice fresh snow a few days ago, about 12-18 inches. I went up to about 11,000ft to do some climbing and found out when my hood was covered with snow, the engine with run rough and even cut-out on the way up the hill. It would also idle rough and even die until I cleaned-off the hood and then she would wake right up. Some guys on Snowest suggested it was a exhaust problem getting clogged with snow. I tend to think it's a intake problem and she's gasping for breath. The guys on Snowest suggested to pipe the exhaust out the side of the tunnel to fix the problem, and they said to NOT vent the airbox in any way because it fouls-up the sensor.
Any thoughts or comments on this sitution? Anyone else had this same problem? How did you rectify it?
Max
Any thoughts or comments on this sitution? Anyone else had this same problem? How did you rectify it?
Max
Y_Rider
Extreme
I had the same thing happen with mine in deep snow. When the track is spinning it fires a ton of snow up the pipe end. Too much back pressure?
I cut the down turn off the exhaust pipe so its pointing almost straight back and then I mounted a plate ( the one yamaha used to stop the track from hitting the old exhaust bracket) below where the exhaust comes out so there is space to vent in to. It's mounted at the rear with spacers to keep the plate about 1 inch below the tunnel at the back. The exhaust can exit to the sides and out the back. I also drilled a bunch of small holes in the plate directly below the exhaust pipe just to make sure.
The posted pics are of the exhaust before I cut it off and the plate doesn't have the holes drilled in it yet. I had it out the other day in snow up to the windshield and it was fine. If the front vents get really plugged up it doesn't want idle right but with some throttle on it is OK. (I've got screens on the center to hood vents) The top of the tunnel gets pretty warm but it hasn't been a issue.
I cut the down turn off the exhaust pipe so its pointing almost straight back and then I mounted a plate ( the one yamaha used to stop the track from hitting the old exhaust bracket) below where the exhaust comes out so there is space to vent in to. It's mounted at the rear with spacers to keep the plate about 1 inch below the tunnel at the back. The exhaust can exit to the sides and out the back. I also drilled a bunch of small holes in the plate directly below the exhaust pipe just to make sure.
The posted pics are of the exhaust before I cut it off and the plate doesn't have the holes drilled in it yet. I had it out the other day in snow up to the windshield and it was fine. If the front vents get really plugged up it doesn't want idle right but with some throttle on it is OK. (I've got screens on the center to hood vents) The top of the tunnel gets pretty warm but it hasn't been a issue.
Attachments
GotJuice
Expert
thanks for pics
This is a great idea! I have a turned down under tunnel exhaust and have thought about changing the way it exits. This is an easy answer to a lot of our concerns, I would like to find a way to attach a hot dogger to the exiting pipe some how. This is the most frustrating thing for me personally about a 4 stroke, no where to put the hot dogger. You can put one against the block but then you have to remove the air box and run filters....Thanks for the pics to go with the idea
This is a great idea! I have a turned down under tunnel exhaust and have thought about changing the way it exits. This is an easy answer to a lot of our concerns, I would like to find a way to attach a hot dogger to the exiting pipe some how. This is the most frustrating thing for me personally about a 4 stroke, no where to put the hot dogger. You can put one against the block but then you have to remove the air box and run filters....Thanks for the pics to go with the idea
maverick
Extreme
Thanks again Y_Rider!! Nice Pics!
Max
Max
niko
TY 4 Stroke Junkie
Great idea, i would think this also would help out with the noise level coming out the rear end.
)
)
Firemann32
Expert
Mine doesn't seem to be a issue with throwing snow in the exhaust as much as the snow getting in the engine, steaming and choking the motor down. There are several threads on the site about wether stripping your hood to cut down on the snow entering the engine area.
hottshot
Pro
Here is pictures of my pipes and sound bite...
I have yet to have a problem with really bogging or anything else but did have to tune the ECM a little.. and No it is not straight piped there is a muffler in there 2 to be exact. As soon as things get settled I will be Dyno-ing the pipes to see the "Proof in the puddin'" if there is any thing and if it is worth it I will be building them for retail.
http://www.youtube.com/watch?v=Lc7dxnot5tE
I have yet to have a problem with really bogging or anything else but did have to tune the ECM a little.. and No it is not straight piped there is a muffler in there 2 to be exact. As soon as things get settled I will be Dyno-ing the pipes to see the "Proof in the puddin'" if there is any thing and if it is worth it I will be building them for retail.
http://www.youtube.com/watch?v=Lc7dxnot5tE
Attachments
niko
TY 4 Stroke Junkie
Can we see a pic of the mufflers?
Yamahammer485
TY 4 Stroke Guru
Isnt your track going to hit the pipes?
My studs hit my corssover tube, and thats how close the back of the track comes to the tunnel under full suspension compression.
My studs hit my corssover tube, and thats how close the back of the track comes to the tunnel under full suspension compression.
maverick
Extreme
Yamahammer485 said:
I was wondering the same thing?
maverick
Extreme
Solution... for now.
Ok. Here's what I've come up with so far to rectify this problem.
I found a vent kit for the top of my Apex airbox on Ebay for a fair price. I have not received or installed it yet so I can not say whether it fixes or improves the problem. In addition to that, I ordered a PowerCommander to richen or lean the mixture. I figure with the Excell exhaust and the airbox vent I'm going to need to fine tune the mixture, especially at the altitude I ride at (8500-11500 ft). I'm also going to do a mod to protect the exhaust outlet, similar to the set-up that you have pictured above Y_Rider. Thanks for the pics!
Right now I think I'm running a bit rich. I've got some black greasy soot around the exhaust outlet and she 'burps' a lot, especially the higher up I go. I'm also hitting the rev limiter (11,000 rpm) nearly all the time I'm at full throttle. Should I be adjusting my clutching? I don't know anything about clutches so I need a little guidance there. Thanks Guys and Gals!
Max
Ok. Here's what I've come up with so far to rectify this problem.
I found a vent kit for the top of my Apex airbox on Ebay for a fair price. I have not received or installed it yet so I can not say whether it fixes or improves the problem. In addition to that, I ordered a PowerCommander to richen or lean the mixture. I figure with the Excell exhaust and the airbox vent I'm going to need to fine tune the mixture, especially at the altitude I ride at (8500-11500 ft). I'm also going to do a mod to protect the exhaust outlet, similar to the set-up that you have pictured above Y_Rider. Thanks for the pics!
Right now I think I'm running a bit rich. I've got some black greasy soot around the exhaust outlet and she 'burps' a lot, especially the higher up I go. I'm also hitting the rev limiter (11,000 rpm) nearly all the time I'm at full throttle. Should I be adjusting my clutching? I don't know anything about clutches so I need a little guidance there. Thanks Guys and Gals!
Max
2XM3
Extreme
Throw a bit more weight at the primary....but the way the mtx is geared you will for sure hit the rev limiter on hardpack, should pull about 10,500 in a climb....
hottshot
Pro
maverick said:
With the help of some with more knolage about such things we did much checking on this very thing b4 I completed the project, and nope no problem. I like to fly and that was one of my main concerns, I will psot pictire of the mufflers later this AM waitin for the wife to get here with the camera.
Attachments
hottshot
Pro
Re: Solution... for now.
Shockwave Adjustable Helix Is the rest of the answer for that problem. If you need more RPM give a little crank if you are bustin the Rev limiter giver a little crank the other way.
maverick said:. I'm also hitting the rev limiter (11,000 rpm) nearly all the time I'm at full throttle. Should I be adjusting my clutching? I don't know anything about clutches so I need a little guidance there. Thanks Guys and Gals!
Max
Shockwave Adjustable Helix Is the rest of the answer for that problem. If you need more RPM give a little crank if you are bustin the Rev limiter giver a little crank the other way.
maverick
Extreme
Thanks hottshot!
How difficult is this Shockwave Helix to install? I'm pretty mechanically inclinded, but I don't have any clutching tools or experience. And where should I go about purchasing one of these and how much should I expext to pay for it?
Thanks!
Max
How difficult is this Shockwave Helix to install? I'm pretty mechanically inclinded, but I don't have any clutching tools or experience. And where should I go about purchasing one of these and how much should I expext to pay for it?
Thanks!
Max
