Bike starts up & revs fine, then won't rev up after 30sec of running

[Greasey Fingers]

sorry guys didn't get a chance to log in for a while, thanks for all the replies I will do the float height check but I'm pretty sure its correct because I took a bit of time ensuring they were exactly 26mm.

I have a feeling the pilot jet is too large, next port of call is to put the original ones back in, the ones I have were from a 'sigma' kit which were guaranteed to be perfect to the set up and altitude you give them

It wouldn't be the needle clip position would it, because that don't kick in till like 4 or 5000 rpm is that correct?

 

[xschris]

My guess is it's the pilot jet. I doubt the sigma kit had the correct type xs360 jets as they are different from othe bs34 carbs. Look at this thread. http://www.xs400.com/forum/showthread.php?t=13892&highlight=xs360+pilot+jets Go back to the stock ones and size of 17.5 I use them in my 80 with pods and 2-1 free flow exhaust. I also only have the mix screws set at 1 turn out. I started at 3 but after a while the plugs would start to soot up.

 

[Greasey Fingers]

sweet chris I reckon you are on the money, cheers

 

[Greasey Fingers]

Oh yeah, what needle position are you running, and your main jet size?

 

[xschris]

Third clip and 135 main.

 

[kshansen]

Third clip and 135 main.

Okay, this may be a little OT but I was wondering if there is an accepted rule for what is called the "Third Clip"? What I mean is that the "Third" groove from the top or the third groove from the bottom? Bottom being the pointy end of the needle.

 

[xschris]

Well you generally start at the top of the needle as it sits in the slide. But for the third clip, which is the stock setting most of the time, top or bottom start would still get you in the same spot.

 

[Greasey Fingers]

Just a quick update on this. Its fixed, chris was bang on the money. I pulled the pilot jets sigma sent me and put the stock one back in. Problem solved, thanks chris! The jets they sent me had holes on the side, the stock pilot jets has NO holes on the side. They tout themselves as experts and you pay for the supposed 'knowledge'....how the fuck can they send me wrong jets if they are experts??????

my 2 cents: DONT BOTHER WITH 'SIGMA JET KITS' from eBay, they send you the wrong stuff and by the time you have gotten around to fitting the jets your dispute time with paypal may have lapsed. They aren't cheap so it was just a waste of money I thought I was paying for something that was going to save me time sorting out the jetting and I just got ripped.

rant over, I'm just happy I fixed the issue...

 

[xschris]

Just because thexs360 uses bs34 carbs don't mean they are the same as every style bs34 ever made. They most likely thought they where the same as the 80's xs400 ones. The xs360 carbs are rare and use a few parts that don'e cross over to any other bike. For one is the pilot jets. Only other bike that used them was the 76-77 xs750.