exciter running lean?

kenziesupra

New member
Joined
Dec 11, 2012
Messages
65
Location
Wisconsin
Hello, I am currently trying to install vmax 600 flatslides on my exciter 570. All it has is a psi pipe and the gutted airbox. I have the vmax slides set up as so:

52.5 pilots
pilot screw 1.5 turns out (btw, which way richens the pilot system and which way leans it?)
3.0 throttle valve cutaway
152.5 main jets
sx nozzles and sx needles (clip is all the way at the bottom so the needle is as rich as possible)

The problem is that it's running extremely lean. It wont run (even when warm) without the choke completely up and even with the choke up, it eats at the spark plug from being lean. I put vmax 500 needles in it (they came with the 3.0 throttle valves) and it ran much better but with those needles, the pilot system runs very rich (0-1/4 throttle). I've been looking through forums and finding that with what setting I'm at, I should be AT LEAST in the ball park and only have a few adjustments left. I'm stumped.:dunno: I think it is the needle (that needle seems REALLY big) but even with the needle as rich as I can make it, it's still running incredibly lean. Any help would be GREATLY appreciated. Thanks.
 

I have an Exciter with vmax600 carbs, it´s ported and bored over 0.40, pods and psi single pipe aswell. I use the same carb setup as you are:

pilot 52,5
main 157,5
mixture screw 1,5 turn
sx needles and nozzles
clip moved one step (richer)

here´s the thing, i tried to switch to vmax 500 slides though they seem to have the same specs as exciter sx. I found out that it didn´t work the way i expected with those.... sled went crap, extremely lean refused to run without the choke on. Switched back to my vmax 600 slides and it was back to normal again. My sled is never lean works really good with the setup written above. i got egt meters and checked it several times and it´s all good. (this doesn´t mean that it´s ok for your sled but use it as a guideline). Hope this will help :)

U can also join us here, we are a pretty big bunch specialized in ex570 and we love to help out fellow exciter enthusiasts!

https://www.facebook.com/groups/377732505654647/

join the excitement!
 
Well, I tried it and it ran better but now I need another sx needle. Unfortunately, everywhere I check, they are discontinued. I can't get one ordered anywhere because yamaha discontinued it. Any ideas on where I could find one?
 
Great Site! I have just recently purchased three exciters for project work an 88 and two 89's. Two of the sleds are together for the most part and will start but need much attention. The third is still in boxes. I have a already learned a lot already from your site on jetting, set up and some pitfalls to watch out for. Will reach out to the members from time to time as I get stuck on issues. I am currently focused on the 88 replacing fuel lines and ensuring I have the carbs correct. The Air box is a real bastard if their are simple modifications that can be made to the box so that it is more serviceable I would love to hear about it. I will post some starting pictures soon.

Thanks Michael
 
The air box is not as bad as everyone makes it out to be. To service the carbs, take the three bolts out securing the box. This will give you enough wiggle room to easily remove the carbs. Its a tight fit, dont get me wrong. The rack carbs are definitely a bit more difficult to get in and out. Especially when its cold in the shop. A little bit of spray silicone inside the air box boots does wonders on the install. I always remove the clamp on the air box boots then open them completely to re-install once the carbs are in place. This saves a lot in the swear department.
 


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