Super Jet reading piston wash with castor927 oil?

A

aramis

Location
Rochester, NY
Curious how my piston wash looks, as I remember reading somewhere that it may look different when using Castor927 but I can't find that post any more...

701, stock porting, 180 psi (35cc domes), EPIC ignition, stock 38's, b-pipe, proks.

piston wash_front.jpgpiston wash_rear.jpg

Pic on left is the front cyl.

Trying to figure out if my jetting is OK, as it had a 70 Pilot with 1.5 N&S with 115g spring in there. I've got some jets and N&S and spring combos on the way and want to experiment intelligently...

This was after about 8 gallons through it with the default EPIC curve...
 
Sospikey

Sospikey

Trying to get upside down
Location
Sweden
Using the Proks means that you would normally need the 95 gr spring with that N/S to get the right "pop". The wash doesn't look to bad, I'd say slightly lean. What high speed jet are you running? How does it run?
 
A

aramis

Location
Rochester, NY
it's always run really good...very smooth power delivery with no dead spots, no matter how I get on the throttle. But, I'm always wondering if there's more power or pop to be found by setting it up "right". It had a 135 main in there. I'm thinking that with the 70 Pilot and 115g spring, it should have been lean on the bottom...does that make sense? I've got 75 Pilots, 95g springs and a pop-off tester on the way.

I think stock spec (and Factory Pipe spec) is 55psi pop-off...is that where I should stay, or should I be looking to go down to 32-ish? I hear of everyone running lower pop-offs than me, but that may be since I'm using the stock 38's???

I've had an issue the last 3 rides where it was acting up at low RPM's...didn't know if it was because maybe I was on the hairy edge of being lean down low and that came out with the colder air/water temps, or if my charge coil was on the fritz. Since I've never "gone through" this ski before, I decided to get the coils rebuilt and also learn more about carbs while that was being done...

I'm also going to run waxhead's curve for the EPIC, which I think means I need to make real sure I'm not lean down low...I might dabble with the reverse jetting stuff, but not until I understand normal jetting first!
 
A

aramis

Location
Rochester, NY
The problem is that FP's instructions says "spring: stock (95gram)"...but Mikuni, Chuck (SUPERTUNE) and other sources say that 115g is the stock spring, not 95g. So, did FP mess up when they said "95g" or did they mess up when they said "stock"? That's part of what I'm trying to get to, as a part of better understanding my motor and carb jetting in general.

Anybody see anything else on the piston wash? Does running Castor927 40:1 really skew what I'm looking for?
 
Hirschfelt

Hirschfelt

Location
Buffalo, NY
Hydroman and I were just discussing his piston wash last night. There is a great thread on piston wash some where on the x. Clean piston top was rich from unburned fuel being sent out the exhuast and black/brown out to the edges was lean. Ideally you want a silver dollar sized black mark in the middle of piston with that fading out to clean circumference. Those were the notes that I wrote down in my notebook about that thread. I will see if I can't find it. From those pics and the info from the other thread I would say lean condition.
 
A

aramis

Location
Rochester, NY
me too...still...I know I read a comment about how Castor927 would make the piston wash "read" different, and if that's the case then my guess is that I was really lean.

Think I found a problem in my carbs (in other words, never trust what you are told is in there) which would have made it really lean down low. Just trying to confirm and learn as I go...I'll know more after I finally get out to ride again today.
 
A

aramis

Location
Rochester, NY
yeah, I know...I've got the PET-2100DX tach, and the thing has sat in the drawer all summer. I can never, ever seem to find enough time to be at the water to tune it properly. It sucks.

I posted originally as I was trying to confirm if I was running lean or not, as a way of troubleshooting a problem I started having. The wash looked ok to me, but then I know I read somewhere about Castor927 carbonizing differently so I wanted to double check.
 
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