Engine stalls on full throttle

[Todd3682]

Let me start by saying thank you for all of the information on this forum. I purchased a 2000 Virage TX about a year ago and thanks to this forum, have learned a lot about my ski. I honestly was clueless when I bought it but am glad I did. It ran fine when I bought it accept for one issue I'm hoping someone can help me with, and still runs good. It's still running good since I took the advice here to replace fuel lines and clean/rebuilt the carbs. Had someone do it for me who has done it a bunch.

i tried to post to my old thread from a year ago, but not sure if that was the right way to do it so I created this new post. The problem is that when I idle out for a few minutes, then squeeze the throttle all the way, the engine stalls. I can start it right back up. If I lightly accelerate for a few seconds it's fine from that point forward. It seems like once it warms up it runs much better. I tried increasing the idle screw a bit to see if it has to do with the amount of fuel being delivered to the engine, but that doesn't seem to help much. Next thought is the low speed screws needing to be adjusted. Before I go there, I thought I'd see if there was anything else it could be. Honestly, this issue isn't a huge deal, because I know if I accelerate slowly, I can usually get around it. But it's more of a challenge/annoyance at this point.

Many ideas would be greatly appreciated.

[HiPeRcO]

Accelerator pump?

[Todd3682]

Would that make sense though since it isn't usually an issue after its warmed up?

[ZeeC]

I would try opening the choke a little and see if that helps.

[Todd3682]

Thanks Hiperco. I'll give that a try. If that helps, what does that mean the issue is? Seems like a fuel issue.

[Todd3682]

After continuing to read up and rack my brain on this, I decided to inspect the fuel tank check valves. The vaccum check valve seems to be working fine. But the relief check valve wouldn't give when blowing into it. Took a bit of time but I was able to blow a bunch of gunk out of it and it does open up, but I have to blow extremely hard into it to get the valve to open up. Much harder than sucking in for the vaccum check valve. Is that normal or do I need to replace that check valve? Not sure if this could be causing my stalling on WOT problem after idling for a while. Seems like it could be though.

[K447]

After continuing to read up and rack my brain on this, I decided to inspect the fuel tank check valves. The vaccum check valve seems to be working fine. But the relief check valve wouldn't give when blowing into it. Took a bit of time but I was able to blow a bunch of gunk out of it and it does open up, but I have to blow extremely hard into it to get the valve to open up. Much harder than sucking in for the vacuum check valve. Is that normal or do I need to replace that check valve? Not sure if this could be causing my stalling on WOT problem after idling for a while. Seems like it could be though.

Going from memory, the fuel tank pressure release check valve opens at 2-3 PSI, which is hard to achieve using mouth and lungs.

The vacuum relief valve opens at a much lower pressure difference.

[Mr. GP1800]

Your accel pump is probably losing its prime and takes a little bit of engine running to get it primed again. If its working fine when the engine is warmed up I would not be too concerned about it.

[ripcuda]

My carbed 1200 in my Rio also does this... to which I've attributed to being a little rich on the low end... and "loading up" at idle.

So if after idling and you punch the gas... if it stumbles and blubbers... then goes... it's too rich down low. If it just falls flat on it's face or dies/stalls... it could be too lean (bigger deal).

What does the piston wash look like?

Cheers!

[Todd3682]

Yeah, it's been doing this since I got it over a year ago. It stalls out the second I squeeze the throttle unless I feather it. The accelerator pump losing its prime seems to make the most sense at this point. Is there anyway to fix that or do you have to replace it? Seems like a low speed adjustment wouldn't be too hard to do if that could potentially be the issue. Thoughts? At this point, not sure how much money I want to put into it if I'm not sure of the issue.