Update this is now a sticky. Got to like that. 
Should make this a sticky a lot of people cant seem to find this post.
Should make this a sticky a lot of people cant seem to find this post.
I have now changed my gearing for flat land and am now running 24 top with 40 bottom with 70 link chain. Took the sled out for about 50 klics and she is still pulling hard but not enough snow yet to really open her up to see the rpms. I will post back when I get the final rpms. I was running 10400 to 10500 so with this gearing I am hoping she is down to 10200.
Well i was able to get out on the field today and open her up and she is at 10200 and pulling hard. I had a smile on for the whole 75 miles I was able to put on. Not much snow here but enough to ride just have to be careful and watch for rocks in the fields.
stomper
TY 4 Stroke Master
I have been going through this air box mod thread carefully so I can get it right the first time. I am doing this mod on an 03 rx1, 136" track, elevation 997 ft. I am using 165 main jet (because I already have them) I have cut all the holes in the bottom of the air box already with exception of the ones by the small foam peices (because of the 165 mains. I will open them up if needed). I am ready to cut the holes in the baffle but I am somewhat confused on the size of area to cut. In sled dogs original post he says 14 sq inches but the original factory holes are already 14 sq inches. I must be missing something. Can anyone please tell me what the total area is of the holes in the baffle. Should the area of holes in the baffle be the same and the holes in the bottom of the air box?
Read it again i do not say square inches i say total inches and i also state that i measured diameter only. So if i said two inch it would be a round two inch hole. There is a total of 14 inches of diameter in all the holes in the baffle. Hope this clears things up.
stomper
TY 4 Stroke Master
Gotcha, I will adjust accordingly and hope for the best.
stomper
TY 4 Stroke Master
Well I did this mod last night and took it for a spin. As mentioned before I am using 165 mains because I already have them. Pilot jets are stock or what ever was in there. I never opened up the whole air box like sled dog did because of the 165's. He said open it up bit by bit until I get the right plug burn. Seems to pull real hard out of the hole and keeps going (with no bog at all. WHEW!!!). It lifts the skis out of the hole and It will lift the skis when I punch it at 30 mph. Never did that before. COOL. The throttle response seems to be lacking a bit, not sure if it's my imagination or not. I believe it had the stock springs in it, so I tried some yellow ones that I had. It didn't seem to make much difference, if at all (imagination or not. dunno). I also have some silver springs that I might try to see if it makes a difference. I haven't checked the plugs yet because I haven't had it out for much of a spin. I will head out tomorrow for a longer ride and then check them. It's snowing like crazy and it is very hard to see at faster speeds. Been crazy with the snow. I have to plow the drive way every second day. But at least there is enough to sled.
Would not hurt to run some startron and or seafoam in one tank of fuel just to make sure carbs are clean as well.
stomper
TY 4 Stroke Master
I have already run a couple tanks with seafoam this year but a few more will not hurt.
I am just heading out now for a better test run and will post results.
I am just heading out now for a better test run and will post results.
Make sure your airbox is on correctly as well this will cause a mid bog.
stomper
TY 4 Stroke Master
Well just got back from a 15 mile ride. I guess it was the rum that I was drinking last night when I was doing the mod because it's running dam fine today. There is no bog and it pulls hard all the way through and the throttle response is good. Starts in the cold alot better also, if you can call -10C cold. We have about 14" of powder on the lakes and before this mod my max speed was 68ish mph and now I am getting 75mph. I checked the plugs and it is real hard to tell whats going on because they are new and they are burning real clean. Not much of anything on them, but if I had to guess I would say they are burning a bit lean. Looks like some small areas of white on them but it's hard to tell. What would be the best to do, get larger jets and leave the air box or plug some holes in the air box. I find it strange because I didn't open up the air box that much, at least not the baffle anyway and the baffle should be the one that counts shouldn't it. It really shouldn't matter if the bottom is opened too much because the air has to go through the baffle to get to the carbs. May have to drive it for awhile to tell. If they are burning lean and I drive it like this for a bit is there a chance of damage to the engine.
If and I doubt that you are running lean 15 minutes on new plugs is not enough time to get a good color read. The beauty of a 4S is that it is not prone to damage like a 2S in a lean condition it will just not make the power that it could. If you find that you are running a tan color that is perfect you have nailed it for your elevation. if you find that your color is more white than tan then go with the 170's. Enjoy your new power I bet you were grinning on that ride. lol
stomper
TY 4 Stroke Master
Cool, Thanks for all the help on this sled dog. I will run it like this for awhile and see what happens with the plugs. On the baffle all I did was, on the big holes I extended each hole sideways 1" and on each of the small holes I extended them 1.5" side ways. Thats only extended on one end of each hole too, not both. So really didn't open it up very much.
You bet I was grinning.
You bet I was grinning.
Lets see what your plug color turns out to be and if its nailed tan you can post some pictures of what you did to the baffle. Your also correct its the baffle that counts for regulating the amount of air into the carbs.
stomper
TY 4 Stroke Master
Will do.
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