Blaster piston wash with big jets
- Thread starter catpower
- Start date
pop off 32 psi
pilot jet 75
main pto 155 mag 152.5
low speed screw 3/4 high speed screw 2
mix at 40 to 1 with super M
pro-tech mach pipe.
ported 61x
lighten flywheel
msd
modded 38's
10/16 hooker with mag pump stubby cone
ewci and jetworks stinger valve.
bypassing water from pto cyl outlet to pipe
runs hard, How can I have such dark carboned pistons with this jetting?
pilot jet 75
main pto 155 mag 152.5
low speed screw 3/4 high speed screw 2
mix at 40 to 1 with super M
pro-tech mach pipe.
ported 61x
lighten flywheel
msd
modded 38's
10/16 hooker with mag pump stubby cone
ewci and jetworks stinger valve.
bypassing water from pto cyl outlet to pipe
runs hard, How can I have such dark carboned pistons with this jetting?
schicks
Karma Enforcer
- Location
- West Michigan
i had a similar problem. Have you done a leak test? I found that I had an air leak in the case behind the flywheel. Since this section is technically sealed by the flywheel cover, the motor ran fine and didn't experience runaway's from it. Could also be a leaky crank seal behind flywheel. I run superM oil as well...not sure if that has anything to do with???wouldn't think so. Mine ran really good to! This is why you can't judge to much off plug readings...my plugs looked fine, but the piston wash tells a different story.
- Location
- Long Island , NY
Scary lean
Fro Diesel
creative control
- Location
- Kzoo
Good info on this thread.
Sent from my PC36100 using Tapatalk 2
Sent from my PC36100 using Tapatalk 2
Good to know, about leaks. Motor was rebuilt 4 years ago and I did a leak test at that time. All new OEM gaskets and crank seals were used. Read a post recently about check valve on fuel tank for air breather connected to water separator. I noticed the hose was kinked so I checked the valve and it is bad. I wouldn't think this would cause lean but then again hose was kinked so maybe I'm starving fuel supply? This motor runs like a freak, pulls hard all through rpm. They always run best just before they blow. I'm hoping to finish year out. Trying to avoid long wot runs.
It is a consensus that it is lean. How do you know what throttle position is lean? Or is it just lean on average? Any tips for correcting? Is there a way to narrow down the low speed from the high?
I am still getting my skills at tuning and appreciate any advice.
I am still getting my skills at tuning and appreciate any advice.
schicks
Karma Enforcer
- Location
- West Michigan
let us know what you find out. im curious
Lean can happen at any throttle position. Full throttle condition would allow for max air but less fuel. A lot of heat possible detonation. I'll see if I can find some kind of sewer pipe plug to seal of head pipe so I can quickly pressure test motor. And Intake of course. That one is easy. Ill be sure to post again but may be some time, have lots of irons heating this summer.
schicks
Karma Enforcer
- Location
- West Michigan
hold off on your leak test for a couple of days if you want. I am starting to think that it is the oil. Similar to you, I ran superM in my ported 701 for years and years with no issue (and it hit hard!!), i noticed recently since i've been getting more into tuning that my piston head readings were telling me it was ruinning lean, and it was jetted rich. I just tore that motor down the other night and installed a jetmaniac bigbore. I just put one tank through the new engine and i looked down the plug holes and could see lots of carbon on my piston already. Now I know that this motor is fresh and can be fairly certain there are no air leaks. I am going to run a tank of different synthetic oil and see if that makes a difference. I am thinking it will.
I think it is also important to state that my previous motor was in good shape when tore down. I still had cross hatching on the cylinder walls and everything looked normal to me with the exception of the piston wash. I will give an update after the weekend.
Also, my piston was looked almost exactly like yours.
I think it is also important to state that my previous motor was in good shape when tore down. I still had cross hatching on the cylinder walls and everything looked normal to me with the exception of the piston wash. I will give an update after the weekend.
Also, my piston was looked almost exactly like yours.