ROCKERDAN
OCD Sledhead
- Joined
- Oct 8, 2005
- Messages
- 7,503
- Location
- Huntsville Ontario & Niagara NY
- Country
- Other
- Snowmobile
- '18 RTX 50th "Winder"
Hey guys,
After talking to some guys on here and doing some research i decided i wanted to FIX my secondary,and remove the float....many racers have agreed that a fixed secondary can help speed,as long as its fixed in correct spec....I thought i would take some pics to show what i did,to fix it and also lock it down without creating SIDE pressure on the jackshaft bearing.
First i used a straight bar(must be perfect straight)..i actually found that home depot sells stuff like this cheap..its approx 3/8" stock,but check as you buy one cause many of them are bent slightly,being straight here is critical.
The spec here is 15mm from backside of primary to backside of secondary....using the straight bar,hold it on back of primary then measure to your backside of secondary,i slid the secondary all the way INward and mine stock measured about 17.5mm....some have said they measure 18mm...So i removed the 1 thin shim from behind secondary and left the larger washer which is special to rest against bearing(its dished out on backside) I then slid it back on and measured again,perfectly at 15mm...so that is where i want to lock it down.
Now because i removed a shim,there is even more float on the alum tube which bolt goes thru....So now you need to take out the float with shims,and the trick here now is to use a rubber O ring,so you dont load the bearing with side pressure.
I ended up finding a 3/4 inch by appox 1/8'' thickness heavy fat O ring in plumbing section at home depot....this size was tough to find,the hardware dept only had thin ones in 3/4" diameter.This fat O ring was perfect for taking out the extra float....
if you cannot find such a fat O ring(1/8") i would recommend using a thinner O ring(easy to find) and getting another OUTER shim from yamaha....you COULD use the inner shim which you removed earlier but the inner shim has a slightly larger inside diameter then the outer shim which sits around alum tube that bolt goes thru.
either way is fine,the idea here is to keep the 15mm measurement on back to primary,and lock it in there.BE sure to set O ring between shims and washer,i dont recommend putting O ring against secondary itself.
here are some pics incase you can't understand what im saying...
Dan
After talking to some guys on here and doing some research i decided i wanted to FIX my secondary,and remove the float....many racers have agreed that a fixed secondary can help speed,as long as its fixed in correct spec....I thought i would take some pics to show what i did,to fix it and also lock it down without creating SIDE pressure on the jackshaft bearing.
First i used a straight bar(must be perfect straight)..i actually found that home depot sells stuff like this cheap..its approx 3/8" stock,but check as you buy one cause many of them are bent slightly,being straight here is critical.
The spec here is 15mm from backside of primary to backside of secondary....using the straight bar,hold it on back of primary then measure to your backside of secondary,i slid the secondary all the way INward and mine stock measured about 17.5mm....some have said they measure 18mm...So i removed the 1 thin shim from behind secondary and left the larger washer which is special to rest against bearing(its dished out on backside) I then slid it back on and measured again,perfectly at 15mm...so that is where i want to lock it down.
Now because i removed a shim,there is even more float on the alum tube which bolt goes thru....So now you need to take out the float with shims,and the trick here now is to use a rubber O ring,so you dont load the bearing with side pressure.
I ended up finding a 3/4 inch by appox 1/8'' thickness heavy fat O ring in plumbing section at home depot....this size was tough to find,the hardware dept only had thin ones in 3/4" diameter.This fat O ring was perfect for taking out the extra float....
if you cannot find such a fat O ring(1/8") i would recommend using a thinner O ring(easy to find) and getting another OUTER shim from yamaha....you COULD use the inner shim which you removed earlier but the inner shim has a slightly larger inside diameter then the outer shim which sits around alum tube that bolt goes thru.
either way is fine,the idea here is to keep the 15mm measurement on back to primary,and lock it in there.BE sure to set O ring between shims and washer,i dont recommend putting O ring against secondary itself.
here are some pics incase you can't understand what im saying...
Dan
Attachments
fourload
TY 4 Stroke Master
Good post dude you are a better teacher than me.......machzed said:Hey guys,
After talking to some guys on here and doing some research i decided i wanted to FIX my secondary,and remove the float....many racers have agreed that a fixed secondary can help speed,as long as its fixed in correct spec....I thought i would take some pics to show what i did,to fix it and also lock it down without creating SIDE pressure on the jackshaft bearing.
First i used a straight bar(must be perfect straight)..i actually found that home depot sells stuff like this cheap..its approx 3/8" stock,but check as you buy one cause many of them are bent slightly,being straight here is critical.
The spec here is 15mm from backside of primary to backside of secondary....using the straight bar,hold it on back of primary then measure to your backside of secondary,i slid the secondary all the way INward and mine stock measured about 17.5mm....some have said they measure 18mm...So i removed the 1 thin shim from behind secondary and left the larger washer which is special to rest against bearing(its dished out on backside) I then slid it back on and measured again,perfectly at 15mm...so that is where i want to lock it down.
Now because i removed a shim,there is even more float on the alum tube which bolt goes thru....So now you need to take out the float with shims,and the trick here now is to use a rubber O ring,so you dont load the bearing with side pressure.
I ended up finding a 3/4 inch by appox 1/8'' thickness heavy fat O ring in plumbing section at home depot....this size was tough to find,the hardware dept only had thin ones in 3/4" diameter.This fat O ring was perfect for taking out the extra float....
if you cannot find such a fat O ring(1/8") i would recommend using a thinner O ring(easy to find) and getting another OUTER shim from yamaha....you COULD use the inner shim which you removed earlier but the inner shim has a slightly larger inside diameter then the outer shim which sits around alum tube that bolt goes thru.
either way is fine,the idea here is to keep the 15mm measurement on back to primary,and lock it in there.BE sure to set O ring between shims and washer,i dont recommend putting O ring against secondary itself.
here are some pics incase you can't understand what im saying...
Dan
SledFreak
TY 4 Stroke God
- Joined
- Feb 7, 2005
- Messages
- 5,514
- Location
- Ontario. Canada
- Country
- Canada
- Snowmobile
- Current 2020 ThunderCat. - SOLD!
Dan, Does the o-ring go around the outside diameter of the inner tube? or does it just rest against it? It looks like you have the secondary, then a spacer, then the aluminum tube, then the o-ring, then the bolt? Correct?
SledFreak
TY 4 Stroke God
- Joined
- Feb 7, 2005
- Messages
- 5,514
- Location
- Ontario. Canada
- Country
- Canada
- Snowmobile
- Current 2020 ThunderCat. - SOLD!
By the way, great report.
welterracer
TY 4 Stroke God
BBY wrote this great post a year or two ago..
http://www.totallyamaha.com/snowmobiles ... hAlign.htm
http://www.totallyamaha.com/snowmobiles ... hAlign.htm
ROCKERDAN
OCD Sledhead
- Joined
- Oct 8, 2005
- Messages
- 7,503
- Location
- Huntsville Ontario & Niagara NY
- Country
- Other
- Snowmobile
- '18 RTX 50th "Winder"
sledfreak...look closely at pics and read closely,you will see the O ring goes around the alum tube...if you were to pu O ring on END of alum tube you wouldnt be taking out the float at all....the float is on the alum tube so you need to take up space on alum tube...this is why you need a 3/4" o ring,which sits snugly AROUND the alum tube...check pics closely.
Also,i forgot to add,when i did this it wasnt compressing the o ring very much,so i filed appox .5mm off the alum tube so the 1/8 O ring would compress enough to make it tight and FIXED.
I havent rode it yet but it is now locked at 15mm perfectly.
Hope the pics helped guys
dan
Also,i forgot to add,when i did this it wasnt compressing the o ring very much,so i filed appox .5mm off the alum tube so the 1/8 O ring would compress enough to make it tight and FIXED.
I havent rode it yet but it is now locked at 15mm perfectly.
Hope the pics helped guys
dan
QCRider
TY 4 Stroke Master
And what was the result on performance?
SledFreak
TY 4 Stroke God
- Joined
- Feb 7, 2005
- Messages
- 5,514
- Location
- Ontario. Canada
- Country
- Canada
- Snowmobile
- Current 2020 ThunderCat. - SOLD!
Ok, so it looks like you are using 1 O-ring, one on the aluminum tube, but you can actually see the o-ring when the bolt is torqued down to the secondary?machzed said:sledfreak...look closely at pics and read closely,you will see the O ring goes around the alum tube...if you were to pu O ring on END of alum tube you wouldnt be taking out the float at all....the float is on the alum tube so you need to take up space on alum tube...this is why you need a 3/4" o ring,which sits snugly AROUND the alum tube...check pics closely.
Also,i forgot to add,when i did this it wasnt compressing the o ring very much,so i filed appox .5mm off the alum tube so the 1/8 O ring would compress enough to make it tight and FIXED.
I havent rode it yet but it is now locked at 15mm perfectly.
Hope the pics helped guys
dan
dirkdiggler
Suspended
There is a super easy way to do this. All you have to do is bolt the secondary down hard. Put the sled on a warm up stand and run it up and spin the track around. Do not stop the track with the brake, Simply let it come to a stop on it's own. Shut the sled off and look at where the belt is positioned in the primary. It's most likly going to be pressed against the fixed sheave. At this point you will start shimming the secondary away from the bulk head. Yamaha makes 2 different thickness shims. Add one and Repeat this process until the belt is centered between the fixed and movable sheaves.
SledFreak
TY 4 Stroke God
- Joined
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- Canada
- Snowmobile
- Current 2020 ThunderCat. - SOLD!
If you just make sure that the offset is at 15mm, will that be enough?
dirkdiggler
Suspended
SledFreak said:If you just make sure that the offset is at 15mm, will that be enough?
Not sure
blackGt
Veteran
when you straight edge the primary to the secondary is there a difference in spacing between the front edge of the secondary and the rear of the secondary?
SRXracer
Expert
It should measure the same front to rear, although i always wondered about setting it a slight angle to account for chassis flex under power? There is a special tool (basically a bar with the 15mm offset cut into it) out there that makes this really easy too.
what is the main purpose of this,increase in performance???
welterracer
TY 4 Stroke God
Increased belt life and drive train effeincy
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