2005 J115PLSOR intake overpressure/raw gas?

[Harkonnen]

OK... saga continues. New powerhead, redone carbs. Engine sneezes at idle, crossflow line come off fittings (at green arrow, view from starboard), and a spray of fuel comes out of the line.

Can't think of anything other than excessive intake pressure, and don't see any way for that to happen other than reeds going bad (looked OK on disassembly). Thoughts?

 

[dingbat]

OK... saga continues. New powerhead, redone carbs. Engine sneezes at idle, crossflow line come off fittings (at green arrow, view from starboard), and a spray of fuel comes out of the line.

Can't think of anything other than excessive intake pressure, and don't see any way for that to happen other than reeds going bad (looked OK on disassembly). Thoughts?

Primer solenoid open / leaking?

 

[Harkonnen]

Primer solenoid open / leaking?

Didn't think of that, will check next, thanks. It does click as it is supposed, though, and I don't see how it would create overpressure, though.

 

[racerone]

Crankcase pressure is not that high.----And a bad reed valve would mean LOWER crankcase pressure

 

[Harkonnen]

Crankcase pressure is not that high.----And a bad reed valve would mean LOWER crankcase pressure

Except that I am talking about pressure NOT in crankcase, but in the intake tract between throttle plate and reeds. Which should be atmospheric or less, because of the sucking action of the case. And if it is ABOVE atmospheric, as stuff spitting out of the tube suggests, where, in your opinion, that overpressure comes from?

Here's a picture - same line, port side, stuff spitting out with some force:

 

[racerone]

Are you seeing this " leakage " with the hose off a fitting , with the motor running?-----Is this part of the oil recirculation ?

 

[dingbat]

Didn't think of that, will check next, thanks. It does click as it is supposed, though, and I don't see how it would create overpressure, though.

Electric or pulse driven fuel pump?
Leaking fuel pump diaphragm?

 

[Harkonnen]

Are you seeing this " leakage " with the hose off a fitting , with the motor running?-----Is this part of the oil recirculation ?

Correct. This is a frame from a video with engine running. The line is the same line shown in the first pic, only the other side, and it was blown off its fitting.
Based on what I am hearing at the local shop, it is supposed to recirculate excess gas from the crankcase back to intake. So, if true, my questions are:
1. Why in the world it is flowing in the opposite direction and where intake pressure comes from?
2. Isn't there a check valve to prevent just that?
4 hours on powerhead; check valves came from the rebuilder with it, so I presume they are OK. The only thing not redone in the intake tract is the reeds, and it was sneezing like that before rebuild as well.

 

[Harkonnen]

Electric or pulse driven fuel pump?
Leaking fuel pump diaphragm?

1. Pulse
2. Not likely. Old VRO was leaking into pulse hose (I think I grumbled about it on this forum), but replacement is only 2 years old, I believe. Did not solve smoke problem (separate, but probably related issue) much, either.

 

[racerone]

Replace the hoses going to the fittings and put small zip ties on them!-----And " excess smoke " on startup is normal on a 2 stroke.----That smoke alarms folks.----And in my opinion that is because the lubrication in a 2 stroke is not well understood !

 

[Harkonnen]

Replace the hoses going to the fittings and put small zip ties on them!-----And " excess smoke " on startup is normal on a 2 stroke.----That smoke alarms folks.----And in my opinion that is because the lubrication in a 2 stroke is not well understood !

Is there a useful diagram of those connections out there? Solis manual is not too much help.
Too much even for a 2-stroke, IMO. I can shoot a picture, I imagine.

 

[racerone]

A factory manual has the diagrams.----Does the " extra " smoke clear up after 10 seconds ?

 

[Harkonnen]

I hope it does. Just ordered one. Surprisingly cheap, but a pain to find.
No, but after a minute it sort of gets to what I expect to be normal for a 2-stroke.

 

[Crosbyman]

2 strokes get 30-40% of their fuel oil mix sent out the window of open exhaust ports when both upstroke inlet ports meet downstrokes open outlet ports on pistons and the new load of fuel oil comes in the cyl.......... only to escape.

That is why DI engine are so economical ... ETEC like 2 strokes or conversional 4 strokes