YAMMIGOD,clutch help for vintage vmax.

SamueLJackson

SamueLJackson

Member
Ike and I are having problems with our old max. After we changed carburetors engine wont pull right under 4800 rpms and we have tried different jets zillion times.. :cussing: Stock clucth spring in our max is comet yellow/white. Were can I find preload etc values for comet 102 c springs and what spring could or would be good for engament rpms 4800-5000.

Thanks guys

-sami-
 
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DUDE, THIS FOR A 540 VMAX ? IF IT IS, THE SPRING YA NEED IS A COMET PURPLE. 207758 IS PART #. THIS SPRING SUPERSEEDED THE COMET 102c YELLOW THAT WAS STANDARD ON THE YAMAHA,s UPDATED WITH 102c. !! 3:16 (tony)
 
Yep. We are looking for help to clutch that 540.

Need a spring what rises the engagement to 4800-5000 rpm range. Will that purple do or is there a another one even better? Will weights have to be changed also?

And Tony, thank´s again.:bowdown: Comet clutches aren´t that well known for us. Sami can do almost anything with the Yamaha ones, but this is a hole another ball game.

Ike
 
PURPLE IS THE TICKET DUDE. WILL PUT YA RIGHT ON. ALSO YOU CAN ADD AFEW SHIMS IF YA NEED THEM TO PRIMARY COVER. COMETS ARE EASY !! 3:16 (tony)
 
Tony, seems like we are the only ones talking here! LOL Others are waiting and writing down this all...Thank you ! This is great info. :urock: :urock: :muahaha:

Sami , you got this now?

Ike
 
Jep I`ll got that now and I am ordering that purple spring tomorrow. Tony you make this all way too easy:bowdown: It would be awful job to test and tune by self so thanks again. Iam prepairing little vmx 540 surprise to our club members at our annual dragrace event under 600 cm3 class. My girlfriend wants to ride "little max" at that race and it suits for me because she weights over 20 kgs less than me.

Last year ike was surprised by little max. Ike said that "this sled wont go anywere" because we had huge bog at low rpms. But when Igot little max over bog to higher rpms I suddenly started pulling away from ike and my late piped xt 600 what he was running.

We have 3 monts time to prepair our sleds to that event. And now we will get more podium finishes. Last year we were 3th (me under 600 class) and Ike was 6th at class over 700. This year I will take part to under 700 class too with my srx.

Ike I think we have to order some stickers to our sleds with text YAMMIEGOD RACING

:super:

-sami-
 
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SJ, I drag raced VMX 549 for years and did very well. My buddies and I still vave a 84, 85 (the old drag sled) and a 86 that I run personelly. Need to know a few things first?
What clutch? 102C or 108
Stock secondary?? What helix?
What jetting. Are powerjets still in use?
Any engine porting or head milling? Let we know what you have and L'ii give ya my 2cents.

VMAX535
 
Vmax 540 is still stock. When we bought the sled it was a mess. And it took a year to find out the electrical problem of engine. Pulser coil wire was almoust broke and under tape. So when I measured coil resistance everything seemed to ok but engine wouldn`t run properly.

We had to replace orginal carbs too and now we are using bored 39.5 mm flat slide carbs. Carb swap had caused grey hairs:cussing: to me and I cant find right jets to get engine pull under 4800rpms. Top end is ok with 320 size jets and needle position is right too, belive me I have changed both million times. Pilot jet is now 42.5 and I have tried everything between 30 - 45.

So all info between piston mods and heavily modded race engine is welcome.

-sami-
 
SJ, The problem between idle speed and 4800 rpm may not be carbs at all. I have never run flat slides on any of my Vmax 540. Go to vintagemax.com and ask on there message board. Chuck (Vmax 540) may even see this and comment.

What I can tell you is that the 540's are very hard on clutch components (something we can go into later if you want) espesially rollers. If you have any movement between the pin and the roller it will effect performance when you nail it. What happens is the the roller position moves down on the fly weight at idle and it is like starting out in second gear. The same thing happens if the bushings in the flyweight are worn. These sled like tight drive belts. So ensure that the C-C measurement between clutches is set and then shim the secondary as needed. Also check the that there is no play in the jackshaft bearing. If the bearing is gone the C-C will be effected. Stock helix is ok 47? Twist secondary to B-3.

The A-3 weights in the primary 102C clutch are OK to use but if you need to buy new ones get some A-2's. The A-2's and the blue spring should work pretty good. Fine tune so your shift rpm does not exceed 8250 rpm.

Let me know how you make out.

Picture of my 96 800 with a ripsaw and my 86 540 in the background

/Dan
 

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I second the YAMMI GOD stickers,Tonys been a great help to all of us.
I have 102c with c-1 weights,2 shims and purple spring and engagement shows 46-4700 on my tach which is probably not exactly rite but deffinetly less bog and no dog.I'm thinking about that digitron with tach and dual egt for my old girl.
Good luck fellas
 
Bubs, your c-1 might be fine on your 440 SRX. But will not perform very well on the VMAX 540. Motor will rev around 9000 rpm. Your 102C also has 2 an extra spacer between the spyder and the shaft. That is not required on the 540cc since the weight profile between A and C weights are totally different.

Good luck with you srx they are fun sleds.
 
Its raining here for days,I love for it to be the fluffy white stuff.We would be SO SNOWED IN!!!:i_need_sn
I understand,Your hp and gearing is different than 440 SRX.Have fun,I hope you guys have snow.Later
 
ALL THE A'' SERIES COMET WEIGHTS HAVE SAME SHIFT PROFILE. DEFFERENCE IN THESE ARE WEIGHT IN GRAMS. THE A-2 WERE 48.0 GRAMS. I THINK BUBSSRX HAS N-1 WEIGHTS IF HE IS RUNNING MY CLUTCH SETUP FOR A 1980 SRX WITH A COMET CLUTCH. N-1 WERE 46.6 GRAMS. THE PURPLE COMET SPRING (207758) REPLACED COMET YELLOW (203475). THIS SPRING WILL RAISE ENGAGEMENT TO 4800-5000. ! 3:16 (tony)
 
I ordered N-1 but they crossed over to c-1 just like the yellow to purple spring.I had your part# list in hand and watched the guy looking through the Comet book.I 'm not sure they are the same,I certailnly hope so.
We got some snow last night but nowhere enough to ride on.
Question?How would flat slide carbs affect the 80srx?better or worse?
 
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I THINK I REMEBER THAT BUBS, I KNEW THEY CROSSED OVER SPRINGS. C-1 ARE SAME WEIGHT AND PROFILE AS THE N-1. THAT IS ACTUALLY A NICE SET-UP ON THE SRX. I WOULD GO TO ROUND SLIDES ON THE 80 SRX BEFORE FLATSLIDES. HEY, YOU DON,T HAVE A SPARE 1980 SRX GAS TANK TO YA !! 3:16 (tony)
 
Race prepare for vmx 540

I changed jets (main and pilot) and moved needle clip one step to leaner (2.from top). Engine pulls much better and throttle response is very good. I am using 300 size mains and 35 pilot jets. Yesterday weather was warm +4c (39f) so I think I will go to 30 size pilots to get engine even sharper from low rpms. I am planning to race old vmx against stock V-4 -92 at wednesday evening. After that I know can I go against new 600cc sleds at our club 660ft drag race.

I try put video (6.9mb) so you can hear sound of old vmx 540. If I cant put the video ike will do it later.

http://video.tinypic.com/player.php?v=v45bb7

-sami-
 
Little update..

Changed mains smaller...again and now running 280 size jets. Engine pulls very sharp and spark plug color is now ok, left side little bit leaner than right. Tomorrov back to garage and make cold air intake "kit" and take plates out from air cleaner box.

I try to make a little video when driving test run...so back tomorrow.:4fzfpi:

-sami-
 
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