38 mm mikuni's on a 540 max motor??

chrisrider63 · Post by **chrisrider63** » Thu Jul 23, 2009 10:20 pm

I got a 440 srx but I dont wanna deal with the hassle of tunning it and I dont have cylinders for it and you cant even get pistons from the deal so i was wondering If i could use the 38's that come with the sled?? And how to jet it to use the 440 pipes.

Post by **tyler440** » Fri Jul 24, 2009 10:13 am

you have me confused... 38's came with your 440? 38's belong on a 540 so yes you can use them.... the 440 pipes on a 540 would probably make you lose power so theres no sense in that... unless you dont have 540 pipes... in which case i dont know what to tell you about jetting anyways... start with stock and just read the plugs i guess....

chrisrider63 · Post by **chrisrider63** » Fri Jul 24, 2009 1:49 pm

The carbs that are on my 540 are bigger, I was going to put together a 540 because I just thought the 440 would blow up and I cant find pistons anywhere. I was going to sell my 540 and just the 540 bottom end I have and make a 540 that would be more reliable then a 440.

chrisrider63 · Post by **chrisrider63** » Fri Jul 24, 2009 3:59 pm

The carbs on the 540 are the ones with the power jet and im not sure on the size of them

Bob Vehring · Post by **Bob Vehring** » Sun Jul 26, 2009 1:04 am

All my performance sleds get an EGT gauge, its so much cheaper then buying cyl. for every mistake

Factory jetting is usually pretty rich so it covers most situations the avg. sled will run in to. It keeps things safe, which is fine for most riders. I like a crisp engine and I will jet for the day. An EGT gauge reads temp coming right out of the port and it does it at any carb opening position. With a little parts changing you can keep EGT at the 1100-1200 point in just about any throttle range or outside temp or Alt. It just takes a little playing around to get all the right jets or needles.
Before anyone asks specifically, I haven't done my VM yet, but on my 535 SRV, with pipe, more compression and very ported cyl's I can keep jetting perfect from +30 to 0 by just changing the needle position, but it took a year to find that combination.

So far I haven't decided which carbs to use. I have 2 sets of 38 power jet carbs. I haven't used PJ carbs before. Looking at the layout in the float bowl, on regular carbs without PJ's the main sits down in the brass nut, more or less having its own little pool of fuel around it. On these, thats where the PJ circut is and the main draws off the floor of the bowl. Seems to me that under hard cornering or just plain rough riding, the fuel could slosh to the side and the main COULD just suck air for a moment. If your on the edge, sounds like a burn down waiting to happen. I'm also not sure why there is a need for the additional top end circuit. Very few sleds used PJ carbs, with proper selection of needle jet and needle I don't see why just a main jet shouldn't work just fine. What does everyone else think?

Post by **tyler440** » Mon Jul 27, 2009 8:07 am

chrisrider63 wrote:The carbs that are on my 540 are bigger, I was going to put together a 540 because I just thought the 440 would blow up and I cant find pistons anywhere. I was going to sell my 540 and just the 540 bottom end I have and make a 540 that would be more reliable then a 440.

well im not sure whats on your 540, but stock are 38's

Post by **Vmax540** » Tue Jul 28, 2009 9:56 am

There are guys that have disconnected the PJ's and have no problems but, I have no idea what needles or jetting they use ?

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38 mm mikuni's on a 540 max motor??

38 mm mikuni's on a 540 max motor??

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