25 hp surging

[jham0077]

I've got a little 25hp that is surging/stalling after about 3-5 minutes of wide open running. The motor sat for sometime before I just got it back running late last year. It got a new bubble, filter, and non-ethanol, fresh fuel. The float stuck on it it's first time out after the move so I had to un-stick the valve(stuck closed). I removed the carb to fix that. It was a lot cleaner than I expected since it sat for 5+ years.

When it does it I usually back off the throttle pretty fast cause I don't want it stalling uncon*****ably(never dies). Is this a carb problem, fuel bubble issue? I've always heard once the float sticks, it will always give problems. Do I need to rebuild the carb?

Thanks in advance.

[panasonic]

Please provide data plate information.

I would remove and clean carb(s) thoroughly, remove jets, carb cleaner and compressed air through all passages.

Check fuel pump diaphragm and replace if needed. Try running again.

Also check fuel tank for venting and fuel filter on engine.

[TownsendsFJR1300]

+1 ^^^. Sounds like your running out of fuel at WOT..

Just to add, you don't necessarily need to replace the needle just because it stuck once.

The primer bulbs have been known to fail on occasion. If there's any restriction in there, that'd be a problem.

Probably NOT your issue but easily tested and cheap enough to replace.

Check for ANY potential air leaks in the fuel lines, connections, etc..

[jham0077]

Forgot I posted here....
It's a C25MSHT, 95 model. I'm gonna replace all the lines soon, maybe tomorrow. The bubble, fittings, and tank are new. I've reached back and squeezed the bubble when it does it's thing, it's not extremely tight, but it makes no difference squeezing it.
I didn't have any carb cleaner to blow through it when I un-stuck the float so there may be a little something floating around.
I'll try to remember to post back with the solution.

[TownsendsFJR1300]

Someone recently posted a link (video) about cleaning where the needle goes in and was sticking.

They took an ear cleaner(cotton tip), put it in a drill motor, dipped in Mothers metal cleaner and ran it in the hole(casting).

Once done, it looked brand new, super shiny brass. Fixed the sticky needle too!

Re-reading your first post, seems, in the carb, you only addressed the float sticking issue.

IMO, pull that carb apart, pull all the jets and clean it fully.

Pulling and inspecting the fuel pump, as well...



.

[jham0077]

It was removed quickly as the sun went down, got a quick wiping, lite spray of WD, and put back on by flashlight. I'll clean it well and post back. Thanks.

[TownsendsFJR1300]

It doesn't take much to partially clog and cause issues on those very small orifices...

I like to visually look thru each one. A quick spray doesn't count!!

Good luck hunting and please post back with an update..

[jham0077]

It's been a while but I came back.
I got a rebuild kit and a fuel pump put on it not long after my last post. I just ran it this past weekend and had no issue with the miss/stumble.