Orfice Size for 6v92 TA

[gpatom]

My manual shows .080 for a non-turbocharged engine but does not show what is should be for a turbocharged engine. Is it the same or different? I just don't believe the one I have is correct and could be part of my NO POWER problem. Can someone help me out on this one.   Tom

[makemineatwostroke]

Tom, they both use 0.80 if its a mechanical engine the 0.93 are used in high hp marine engines Tell us how your fuel is supplied to the heads does it have one line going to the right head and a cross over line going to the left head or does it have 2 lines coming from the filter going to each head,if you have 2 lines from the filter you need 2 orifices on the return side of each head but with 1 line from the filter you need 1 on the return line on the left head.Did you do a inframe or out of frame overhaul on the engine.I would take it to Don mention on this board if he is a 2 stroke guy

[Dallas]

Your restrictor orifice should be .080. Your book doesn't show turbo charged engines because it's taken for granted... non turbo 92 series are few and far between.
Look at the restrictor, on the side of it it should have an "R" with a number, hopefully, .080, but it could be anything from .040 to .100. If there is no R number, it isn't the restrictor.
What concerns me is that you fuel pressure is only 30 psi at high rpm. you should have at least 50 and preferably 60 psi or more at anything over 1200 rpm.

Sounds to me like your fuel pump may be FUBAR and needs rebuilt or replaced.

[gpatom]

Dallas, there is not a R number on it because I made the orifice ( I was a machinist by trade). I don't think it is the fuel pump because it pumps plenty of fuel out right now. Right now I have two lines from the filter, one to each head, with two lines out go to a T with a .093 restricter and then to the tank. Tom

[gpatom]

Oh yeah, I did a out frame overhall. Tom

[makemineatwostroke]

That will work Tom but you should have around 56# of pressure at 1600 rpm with a 0.93 orifice check your spring on the relief valve on the fuel pump make it is not broke.      good luck guy

[Dallas]

Dallas, there is not a R number on it because I made the orifice ( I was a machinist by trade). I don't think it is the fuel pump because it pumps plenty of fuel out right now. Right now I have two lines from the filter, one to each head, with two lines out go to a T with a .093 restricter and then to the tank. Tom

Volume of fuel pumped and fuel pressure are two completely different things. .093 is as large or larger than the normal Weatherhead fitting in line.

Why would you machine an orifice when a fitting is only about $5?

[luvrbus]

I think Tom has a timing problem those engines will run on 30lbs of fuel pressure unless the filters in the injectors are dirty.Hope you find your problem Tom and hope it is a easy one to fix for you little adjustments and small things on the 2 stroke will drive you nuts sometimes did me till I replaced the bypass on my blower