650 X2 runs like a bat outta h3ll on slight choke?

[Nottjbarlow]

So I was doing a test and tune yesterday and I thought she was running pretty good but while pushed against the shore and running full throttle I choked the intake with my hand for a second and when I released... holy $h!t.

That thing revved up and about jumped into the parking lot!

The plugs are a nice coffee brown. Is it crazy lean or am i just crazy bad at tuning carbs?

Trying to get this thing ready for some salt tommorrow.

Y'all guru's got any ideas why she is doing that?

 

[Vumad]

Throttle plate is after the Venturi and choke is before. Choke closed causes more fuel to be pulled from the Venturi because the the throttle open lets the motor pull from the intake but not to the outside air.

So high rpm with choke closed pulls extra fuel into the intake and then you open choke and it runs leaner and spools better.

I've never tried doing what you did. I have primer, not choke. Ski should only run on choke to prime the fuel lines. After that if it's running on choke its a sign that you are too lean or you have a weak fuel pump / popoff issues. Should run boggy with choke on or not at all.

I believe.

 

[Nottjbarlow]

Well on Saturday I played with the carb for about 20 minutes and found the low speed adjuster was lean, after adjusting it out about one turn throttle response is now crisp with no low-end lag, she is running so much better now.

I went for a short salt water run on Sunday and she was making plenty of power, at least for 650 LOL.

Thanks.

 

[Nottjbarlow]

Still a little hard to start on a hot engine tho, rich or popoff pressure?

 

[Philip Clemmons]

Running better on choke usually indicates a fuel restriction, as does hard starting. Have you checked the carb condition, and that of the vent, fuel sector, and line? That's usually where it starts.

 

[Vumad]

Still a little hard to start on a hot engine tho, rich or popoff pressure?

Hard to say exactly. Could be lean, could be rich. Could be popoff too high.

If it runs good, don't lower the popoff. Just install a primer and give it a squirt. If it runs poorly, then try lowering the popoff.

You may want to remove, clean, inspect, test and possibly rebuild your carb. Sounds like you may have more issues than your tuning.