VooDoo Max

[Bob Vehring]

Well, she lives again. The stator from Chuck cured the elec. problem, played around with 4 other jugs when I had the engine out, measured the ports on all 6 of them, then just went back to the ones I had to begin with. Desided to try the other carbs before I changed the cyl's. I put taper bored 38's on it because I like the ones I put on the SRV. I spent a couple nights in the shop trying to get the jetting right, I ended up using 6DH2 needles which let me bring the mains down to 320's. Its a lot punchier in the mid range now but still a little fat on the bottom. I went back down from a 50 to a 40 on piolet jet but will change slide taper next.
I changed clutch springs from the silver to a Green/Yellow with the same notched A3 arms, engagement is about 4700 but still only shifts at 7900, have to think about that for a while.
Pretty happy with the improvements, not as fast as the SRV yet, but closer.

[chrisrider63]

Sounds to me like you like your srv bob lol. Cause a good-running max would blow away a srv anytime, mines stock and i can ride with 800's but that may have something to do with the polaris clutches. Im lucky i joined the site last year i knew nothing about the polaris clutches being such a sweet setup i was going to pull them off. But if your max isnt doing circles around the srv theres something wrong. Why not set the thing up stock the way its supposed to run??? With PJ carbs and something a bit stiffer then the stock primary spring. Justin that has the srx 500 told me to run a orange spring with the pink secondary on the 2nd notch.

[mrviper700]

why are you running srx440 pipes on a 540?

[tyler440]

440 pipes on a 540 should make it rev higher, whether or not that is a good thing im not sure... i had thought of experimenting with this but never got to it

[chrisrider63]

I was thinking about putting on the 440 pipes but it really doesnt make sense that they would/could work better the stock 540 pipes make the most ponies as tyler stated in a recent post.

[Bob Vehring]

Chris, if you have read any of my earlier posts, the SRV is far from stock, bigger twin carbs, more porting including extra transfer ports, more compression ,reed valves, gears changed and while I haven't weighted the VM yet I would guess the VM is 30-35 lbs heavier . The SRV was used for racing only for many years
The VM came with a silver spring and A3 wts in a 108. I changed to the G/Y based on what I read here, and agree with the people in that thread, that this seams and feels much better.
Now you guys have me wondering on the pipes. Are you all sayin these are 440 pipes?
These are the pipes that came with this sled, thats all I know about them. I have never had or really looked close at another VM or SRX closely. As I said, yesterday it was shifting out at 7900, maybe 800 on really hard trail, I understand this is 400 short of what I was looking for. But if these are SRX pipes, then I'm way short.
I do have a set of 9300 twin pipes for my SRV from when we raced, but took them off for the trail and put on a Aaen single. I don't want a 9000+ trail sled
How do I know for sure what pipes I have, does someone have a length and dia. measurement for the two different size pipes?

[chrisrider63]

Take a pic bob and post it myself and others would be able to tell the difference from looking at them for sure, also they would have a 8M6 stamp on them on the top i believe.

[mrviper700]

yes,those are 100% 81 srx440 pipes you have on your sled,they run at 9000rpm and your vmax runs at 8200rpm,this is also likely why you dont have any bottomend power. the srx pipe is not a low end pipe like the 540 pipe is, its also much shorter to run a higher rpm,so its definitely making your engine not run to its potential, your loosing quite a bit of power doing this.

to use those 440 pipes youd need to run the engine at 9000rpm, have correct height exhaust port and have the correct ign.timing to go along with it,if your not running this combo,your LOSING power!

[mrviper700]

heres a pic of 440 pipes and a pic of 540 pipes I found here on this site, you can easily see how much longer and much larger center/ belly is on the 540 pipes. longer pipe is lower rpm, shorter pipe is higher rpm. The volume of the 2 pipes is quite differnt as well for the 440-540cc differance.




top pic is the 440srx and bottom is the 540vmax

[Bob Vehring]

Well, that explains alot, I definitely have the pipes in the upper picture. Anyone have an extra set of 540 pipes and how much? I will check around here tonight when I get back from school.
I thought I had 3 sleds ready to take up north in a couple weeks, went out in the shop this mourning, looks like the kid rolled the El Tigre 6000 last night, windshield is smashed, radiator is leaking. Just when you think you have everything done and working...........
Thanks guys for the heads up on the pipes. Bob

[Bob Vehring]

PS, do the different pipes take the same can?

[tyler440]

yeah they will fit the same can

[Vmax540]

PS, do the different pipes take the same can?

They will fit both silencers but, visibly on the outside the silencers are somewhat differently shaped. The 540 silencer has a more rounded mass produced look ?

B.T.W. The 81 SRX WAS 88 HP @ 9250 rpm and the Vmax was 86 HP at ~8250 rpm's (Per. Dyno Tech)

[mrviper700]

per the dynotech article here on this site,they never dyno'd a 81 srx???, do you have a dyno sheet with the information for a 81 srx,I would like to look at the numbers.

[Bob Vehring]

I just need again to say thanks to everyone on this site. Chuck had a set of pipes and they should be on the way, he saved me on the stator a few weeks ago. And thanks to everyone that bothers to read this. I have a good understanding on pipes, what I don't have is much reference on VM's, never saw one close up around here, and never a '81 SRX. I never would have picked that out. Now if only the snow hangs around to try them out.
This is the best forum that I am on, and I do make the rounds.