Plug Chop Results, Does anything look wrong with these?

[DrewNJ]

I should pull the head, but those RIVA girdle bolts suck royaly.

Do you have any links or pictures of a piston suffering from deto would look like?

Should I run a plug chop before removing the head?

No, you don't need to chop before removing the head.
Here are some pics of deto on a piston from a kawi we rebuilt over the winter... This ski was detonating so bad that when we took the plugs out there were metal shavings that eventually blocked the electrode preventing the plug from firing..:ugh:
Yours looks like fuel additives to me.
Good Luck
Doug

 

[Shifty]

Drew, thanks for the pictures. That piston is all jacked up, and mine definitelylook don't like that thankfully.

I pulled the head and it went smoothly, the girdle bolts came out without a fuss (no binding). Here are some shots of the piston wash... if you can call it that. I guess It looks lean eh? I can still see the cross hatching on the cylinder walls, but they look almost glazed? The other thing I noticed is there are a few short shiney vertical lines on the cylinder walls, I cannot feel a noticeable groove there but it worries me:thinking: Could this be considered scoring? Other that that things look good on the piston and domes.

After I reassembled, I did a comp test to make sure the o-rings were seated correctly. The guage read 195 on one cyl then 190 on the next, confussed, I went back to the first cyl and got a lower # again. Turns out my snap on gauge's check valve blew out and would hold the reading:shooter3:

I richened up the highs from 1-1/2 to 2-1/2 and most of the performance is still there, but not quite as snappy down low... I performed a plug chop after this and will show the results, they look a little different...

 

[Shifty]

Here are some photo's of the head at the time of removal and plug chops after bolting it all back up and opening the highs up a bit. I figured I would put them next to some cardboard for a reference as someone mentioned they would ideally look similar in color....

 

[Crab]

Looks a bit lean to me, what brand of oil?

 

[Mark44]

Looks way lean to me also.

Mark44

 

[Shifty]

I am using Yamalube @ 40:1

 

[Frosty]

i really don't like the look of the cyl walls either... they seem to have the same reddish/burnt coloring the plugs have. not sure if it's just the pics though.

i've been running the same ported cylinder for several years using amsoil 50:1 and my cylinder walls still look like the day it was new...

the plugs and pistons look lean...


here's a stupid question for ya... did you remove the dome o-rings for the pictures?

 

[Fro Diesel]

I believe an engine can't run E85 unless it was designed for it.

really, i dont think that statement is totally acurate. I believe an engine shouldnt run it but i have mixed it in various cars (one being my 88 mazda 626 turbo) and some actually run better with a small mixture. I mixed a few tanks with it over a year ago max 20% e85 in a 10 gallon tank. No problems yet. I wouldnt put it in a ski...


Are you sure this engine didn't overheat?

 

[Shifty]

You guys are scaring me, what would cause this coloration / staining of the walls. I did remove the orings from the cylinder they were stuck a little and stayed when I pulled the head.

 

[Fro Diesel]

how is your cooling set up? I may be out of line, but those cyl walls look toasty. Ever check to see how hot your pisser was?:dunno:

 

[yamaslut]

how often do u guys change your plugs??..ive been running the same ones since october?????????

yeah... since about then for me too...

 

[Mark44]

Awww don't worry about it they always run GREAT right before they BLOW!

Mark44

 

[Frosty]

You guys are scaring me, what would cause this coloration / staining of the walls. I did remove the orings from the cylinder they were stuck a little and stayed when I pulled the head.

i don't know... but my 2001 cylinder, other than having been ported, is still std bore... it's very clean - like the day i 1st had it ported.

again, maybe it's just the pcitures how does it look in person.

 

[Shifty]

I have the routing factorypipe recomends, I tapped the the manifold for two inlets but didn't hook it up as I didn't have a 'T' at the time or enough hose to route from the bottom of the head pipe out the top.

So it comes in on one line from the pump, to the manifold then out of the head to top of headpipe through 'T' to pisser T'd to stinger nipple.

I check the bypass quite a bit when running and it is never scalding? Could this high psi head be giving me trouble? I may switch back to stock while I get the dome machined.

 

[Frosty]

so you plugged the second inlet into the manifold?

just so i'm straight... you go into the manifold, out the head to the top of the head pipe, out the bottom of the headpipe to overboard/stinger?

 

[Shifty]

Thats right, I did plug the extra tapped hole in the manifold and the routing is just like you listed. The cylinder looks just like the pictures show in terms of coloration. Is my motor fried or what?

I am thinking that my main jet needs to go up one size because I am using a 135 now and, that is stock FP recomendations, my chokes are removed and this could be the reason for my lean state?

 

[Frosty]

well, one thing is... Yamaha recommends running 50:1 (i'm assuming that's using Yamalube, which you said you use)... http://www.yamaha-motor.com/waverunner/products/modelspecs/139/0/specs.aspx not sure if that would make any difference though.

if you are 2.5 turns out on the high speed adjuster screws you may want to jet up.

 

[Mark44]

o

well, one thing is... Yamaha recommends running 50:1 (i'm assuming that's using Yamalube, which you said you use)... http://www.yamaha-motor.com/waverunner/products/modelspecs/139/0/specs.aspx not sure if that would make any difference though.

if you are 2.5 turns out on the high speed adjuster screws you may want to jet up.

On stock carbs isn't two turns wide open? So anything after that is not increasing fuel.

Sounds like this ski needs jetting help. IMO

Mark44

 

[tor*p*do]

Sounds like this ski needs jetting help.

before it melts down, fatten up those jets!

 

[Frosty]

yup... i would jet up...

here is what my jetting has been on a ported 701cc, 35cc ADA head (185 psi), FPP B-pipe, stock ignition - i have never had any trouble...

Main Jet 135
Pilot Jet 70
High speed screw 1 1/2
Low speed screw 1 1/4
Needle/Seat 1.5
Spring (grams) 95

I know you said you were running 135 mains already... hmmmmmm