vmax4-800
- Thread starter modsrx
- Start date
how much clutch weight a engine pulls is dictated by the primary spring, roller size and gearing of the chaincase, alot of factors in there. So what I am trying to tell you is there isnt gonna be 1 specifc weight.
i know don but i just try to know the stock gramm...to give me a point where to start ..someone sell a set of 8bu-00 to my friend and my friend didnt scale them cause it was suppose to be for a 800 and then it didnt work at all ...i check them on scale and it was total of 58 gram running with a w-w-w im pretty sure that beast can't run more than 53 gram ................. just looking for a starting point
YAMMIEGOD3:16
Active member
55 GRAMS IN A STOCK 800 (8BU-00). NO QUADS, NO BIG BORE, NO NOTHING. '' STOCK '' 3:16 (yammie tony)
YAMMIEGOD3:16
Active member
AND KEEP IN MIND THE 800 HAD ABOUT 9 HORSE ON THE 750. 3:16 (yammie tony)
modsrx said:
I see... but all you would need to do is use a stiffer primary spring and those 58 gram would be fine. Make the chaincase gearing deeper and it will rev more. Tony posted its 55 grams stock with stock spring,gears. You could be running 60-62,-64 grams depending on what spring, rollers,gears you run.
the softer the spring the less weight you can run
the stiffer the spring the more weight youll run
the higher the chaincase gearing (numeric) the more clutch weight it will run
the lower the chaincase gearing (numeric) the less clutch weight youll run
only way to find the fastest set up is to test,take notes and test again. You will slow it down or speed it up, then just refer back to your notes and you should be able to find sweet spot.
YAMMIEGOD3:16
Active member
THE VMAX 4,s WERE CLUTCHED BAD OUT OF THE BOX, WELL NOT BAD, DOCILE. HUGE , HUGE GAINS TO BE HAD WITH THESE SLEDS WITH A GREAT CLUTCH SET-UP. UNREAL THE PERFORMANCE GAINS WITH A GOOD CLUTCH SET-UP ON THIS SLED AND LIKE DON POSTED, YOU HAVE TO TEST, ALOT!!!!!!. I THINK EVEN MORE THAN A SRX YOU CAN GAIN SLED LENTGHS. IN 95 THE 800 HAD THE CURRENT SECONDARY SO ANY HELIX YOU USE ON ANY AFTER 97 YAMAHA SNOWMOBILE WOULD WORK. SO THAT MEANS HUGE CAM SELECTION INSTEAD OF LIKE TWO ON THE 750. PROPER SET-UP VMAX 4 CAN DO ALOT OF DAMAGE !!! 3:16 (yammie tony)
YAMMIEGOD3:16
Active member
THE RODNEY DANGERFIELD OF SNOWMOBILES. '' GETS NO RESPECT ''. I LOVE RACING MINE, ESPECIALLY WITH MY 138 POUND DRIVER. TAKES A HELL OF A SLED TO BEAT THAT OLD GIRL, HAVE TO TELL YA AND I OWN TWO SRX,S, I CRUSH SRX,s WITH THIS SLED ALL DAY LONG. TAKE A HELL OF A F-7 TO TAKE IT. DRAW BACK IS THE SAME PROBLEM FROM ANY SLED OF THAT ERA, HUGE WEIGHT. BACK BREAKING WEIGHT. LOVE GETTING LAUGHED AT UNTIL YOU DRIVE RIGHT ON BY !!! rotflmao 3:16 (yammie tony)
modsrx said:
second test with some gramm remove OMG THOSE VMAX are scarry ...........
max rpm 9200-9300 need to add some now but what a beast .....
we do have alots of belt splip running slow with the w-w-w will try to go at 30kg preload ....clutch getting so hot running slow outch .....need to solved that problem and its gonna be freaky ...sled run with aeen pipe
Rustman
New member
Awesome post! They are special machines to say the least.
modsrx said:second test with some gramm remove OMG THOSE VMAX are scarry ...........
max rpm 9200-9300 need to add some now but what a beast .....
we do have alots of belt splip running slow with the w-w-w will try to go at 30kg preload ....clutch getting so hot running slow outch .....need to solved that problem and its gonna be freaky ...sled run with aeen pipe
Here's what I used with my AAEN quad piped, ported 96 VMAX4 when I used the Yamaha primary[it now has a 4 Pro with 911 cover]
4200 RPM engagement/ 9100RPM shift
Primary Spring:
Yamaha Pink-Pink-Pink 30/129
Weights:
Heavy Hitters 48.5
tip 5.8
tip washer 3.4
first hole .9
-----------------------
Weight Total 58.6
Secondary:
Dalton 53/47
Yamaha Silver spring 70 degree wrap
I found the sled was slower above 9200 shift rpm
This sled has a two up seat, back rest with a rack, 1 1/4 x 136", and tows the ice fishing sleigh...LOL...at 180+++hp quite possibly the fastest 2 up sled out there!
Pics added
4200 RPM engagement/ 9100RPM shift
Primary Spring:
Yamaha Pink-Pink-Pink 30/129
Weights:
Heavy Hitters 48.5
tip 5.8
tip washer 3.4
first hole .9
-----------------------
Weight Total 58.6
Secondary:
Dalton 53/47
Yamaha Silver spring 70 degree wrap
I found the sled was slower above 9200 shift rpm
This sled has a two up seat, back rest with a rack, 1 1/4 x 136", and tows the ice fishing sleigh...LOL...at 180+++hp quite possibly the fastest 2 up sled out there!
Pics added
Last edited:
YAMMIEGOD3:16
Active member
PRE-LOAD IN YOUR SECONDARY IS WAY OF. THATS CAUSING YA BELT SLIPPAGE AND ALL THAT HEAT. TAKE IT UP TO 70. 3:16 (yammie tony)
its already ay 70 tony ......the belt slip eatch time u try to move the sled ..smell rubber u need to push hard on gaz to move from that spot.....sled engage at 4800 but won't move before 5000 so i'm sure its way to high for a trail sled ....went u go mid to top thats ****ing crazy ..im scared of it lolll..secondary stay cool but primary get hot so bad .....does the distance from sheave to sheave in primary could cause a problem for engagement ... i think my friend shrink that gap ..... 
I have found belt allignment especially centre to centre distance is critical on these VMAX4s for performance and especially belt survival. I bought an adjustable belt allignment tool years back and bolted it in a fixed position at the VMAX4 allignment specs...the tool is constantly borrowed by local VMAX4 owners...in fact its out on loan now.
If the sled you are working on is that difficult to get moving you must have some issues.
-bad bearings on jackshaft and or drive shaft
-too high of engagement...under 4500 and closer to 4000 works best
-burned/glazed belt...only use YAMAHA belts thses sled will explode an after market belt...this I know!
-clutch centre distance too short results in belt riding too high in primary causing a lot of slippage to get sled moving as it is starting in too high of gear
Just some ideas
Bob
If the sled you are working on is that difficult to get moving you must have some issues.
-bad bearings on jackshaft and or drive shaft
-too high of engagement...under 4500 and closer to 4000 works best
-burned/glazed belt...only use YAMAHA belts thses sled will explode an after market belt...this I know!
-clutch centre distance too short results in belt riding too high in primary causing a lot of slippage to get sled moving as it is starting in too high of gear
Just some ideas
Bob
sideshowBob said:
thnx bob sled got new bearing everywhere ......suspension its a ad boivin ..sled engage over 4500 for sure and i know on srx if u go over 4000 it doesnt work good at all .......center to center suppose to be good we check it went we put back the motor ....only thing i can see its to high engagement or like i said my friend cut the primary clutch so the sheave get closer
Check the centre to centre distance again and make sure the belt is good...these VMAX4s glaze/burn the belt edges and then the belt slips bad until you put on a new belt.