Snowmobile Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
6 Posts
Discussion Starter #1
1979 Yamaha Enticer 340

--------------------------------------------------------------------------------
I have now replaced my track on this machine I bought from Royal Distributing ,which said I needed to replaced the sprocket to a 11 lug which I have done, and move the track forward by 1inch by drilling the front mounting points on the tunnel which I did, but now find the back wheels are binding on springs! does this mean I have to drill the back mounting poiints as well? dont want to do this until Im sure this is what has to be done, I cannot tension the track anymore as it pretty tight now so any advice would be welcome at the stage thnks
 

·
Premium Member
Joined
·
5,737 Posts
your suspension is based on a geometric concept that needs to remain proportionate to the other pivot points in the equation. if you moved the front mount, the others need to follow. sounds like they sold you a shorter track with limited instructions. my experience is based on the other direction, relocating skids to accept longer tracks, but the same principals apply. can you explain more about the 11 lug concept? i am not following that at all. your not referring to the number of teeth on the track drivers on the driveshaft?
 

·
Registered
Joined
·
6 Posts
Discussion Starter #3
Hi
Thanks for your reply, yes the number of teeth on driveshaft is what I meant I had to change the pitch so it meant upgrading to 11teeth instead of the original 7 teeth,yes the track is shorter as you say but that was all I could get for this machine so now I will drill new holes in the back mounting points and all will be well I hope
 

·
Premium Member
Joined
·
5,737 Posts
i hope so as well. the fact that you added 4 teeth to the drivers in an already close track to bulkhead sled with the 7 tooth drivers and moving it all forward an inch is a concern. heres some math for you to ponder: lets say the pitch of the track is a standard 2.52 pitch. 2.52 x 7 =17.64 circumference. 2.52 x 11= 27.72 circ. 27.72-17.64x.50=5.04". now add the inch forward and is there really room for an extra 6", give or take a half, for the track to move forward and clear the bulkhead? my experience with those machines was that the driveshafts were square vs hex, but square hub drivers were available in the same pitch and tooth count.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #5
enticer340

Now you have me really concerned it looks like it will be really tight as your saying what to do not sure Ive bought the track and listened to royal advice how much clearance is needed at the bulkhead?
 

·
Premium Member
Joined
·
5,737 Posts
i wasnt trying to create panic. things just werent adding up. at the minimum, the track needs to clear. the more space you have, the better the snow will evacuate. about 1/2" clearance is probably the norm or minimum. lets start over and figure out where your at. first confirm tooth count on the new drivers and the ones you pressed off. next, figure out what length track you have and what the pitch is. count the drive lugs inside the track and measure the center to center distance between the lugs. for instance, if the track is a 109" 2.52 pitch, it would have around 43 lugs and the lugs would be about 2 1/2" apart. if the track has all the windows open, you can count the windows and measure from one window to the next. from these measures we can calculate pitch and length. based on your purchase from royal, i am guessing your in canada. i can convert to inches if you would rather do metric.
 

·
Registered
Joined
·
6 Posts
Discussion Starter #7
The track pitch is 3.29 with 33 windows its Kimpex 04-962,yes am in bc canada I have go now but really glad of your help thanks m
 

·
Premium Member
Joined
·
5,737 Posts
i checked out royal and assuming they are on top of their game and you have the correct drivers that they said to get, you should be alright after you move all the skid mount points the 1". again, make sure there is backing in the tunnel to support the skid bolts. the math still doesnt add up, lets hope they know what they are doing!
 

·
Premium Member
Joined
·
2,227 Posts
I think the pitch must be different from old to new which requires the drive sprocket change. I assume the pitch diameter of both sprockets is close or still the same and therefore the clearance remains the same. If I get your story right, the track is shorter which requires that you move the suspension forward and both front and rear should be moved.
 
1 - 10 of 10 Posts
Top