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Curtis B.
Curtis B., Technician
Category: Small Engine
Satisfied Customers: 26054
Experience:  have worked on and around most engine models for 35 yrs./Polaris ATV expert
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I have a great dane 60in cut with a kawasaki 25hp fh721v motor

Customer Question

I have a great dane 60in cut with a kawasaki 25hp fh721v motor started running bad thenews quit while mowing it will start now but barely idle and does nothing if I increase the throttle gas is coming from exhaust manifold only on one side and is also in the oil normally this would be a float issue I took it all part looked good cleaned and put back together same thing...I'm putting a new float and valve on this evening anyway what else could cause this ?
JA: I'll do all I can to help. Is there anything else important you think the Small Engine Technician should know?
Customer: I'm also gonna put a new fuel pump on it this evening just in case just want the other options if there is any is this 100% a float fuel issue could it be valves ?...best course of action if a new float valve fuel filter and fuel pump doesn't fix the problem?
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Small Engine Technician about your situation and then connect you two.
Submitted: 7 months ago.
Category: Small Engine
Expert:  Curtis B. replied 7 months ago.
No, the needle valve and float in carburetor is what causes the fuel to enter the oil and the intake in quantity to flood the engine. They have to control the fuel to the float bowl.
Customer: replied 7 months ago.
So it's safe to say that new float and float valve is gonna fix this issue I'm only wondering cause this float and valve is constructed of polymer plastic and I've heard they rarely have issues also it seemed to be working well but I know this a hard to see problem thanks for your help hopefully this fixes the issue
Expert:  Curtis B. replied 7 months ago.
That is the only thing that can cause it, and the fuel pump is a pulse pump, not block mounted, so it can not cause it. The solenoid in the base of the carburetor is an anti-backfire solenid, and it plugs the main jet, not a fuel shutoff.
Customer: replied 7 months ago.
That was the next thing that's weird when it's rough idling I can unplug that solenoid and will start to run great for min then go back to the same I plug back in for a min then unplug again it will run great for a min then die if I don't plug back in but what does this tell you??....like I said while idling rough barely running I can unplug that solenoid and it's like nothing wrong for just a min it runs great then dies ??
Customer: replied 7 months ago.
Thanks for all your help again
Expert:  Curtis B. replied 7 months ago.
When you unplug the solenoid it closes the main jet, so it is starving the fule to cylinders, so the float and needle valve are flooding the engine. Too much fuel is getting to the cylinders when the solenoid is open.
Customer: replied 7 months ago.
Well unfortunately that did not fix it ...new float, float valve, plugs, oil change, fuel filter and cleaned carb put back together and same thing the thing that gets me is that it's a 2 barrel carb and only one barrel is flooding one cylinder of the v-twin same side always ??....
Expert:  Curtis B. replied 7 months ago.
?? Cylinder not loosing spark and valves have clearnce on the (flooding ) cylinder?
Customer: replied 7 months ago.
It's sparking for sure valves I don't know about but if either of those were the case then disconnecting the fuel solenoid wouldn't make it run great all the sudden correct??..
Expert:  Curtis B. replied 7 months ago.
no, disconnecting the fule solenoid shuts off the fuel, so it is definitely getting to much fuel. Which comes back to a bad carburetor.
Customer: replied 7 months ago.
Yeah the fact that it was running great I was cutting my grass and it just died makes me wonder .....if a valve is stuck or cracked open wouldn't it do the same effect feeding fuel at all times even if exhaust stroke and that would make sense only one side being the problem
Expert:  Curtis B. replied 7 months ago.
Nothing about it makes any sense! But if it runs better when the fuel is shutoff, (fuel solenoid) it has to be too much fuel through the carb! Did you replace the needle valve and seat and the float? And does the float shut off the passage if you blow into the passage and hold the float?
Customer: replied 7 months ago.
I did not replace the seat everything else but yes it was working properly I checked with air and put some fuel in it lifted up and down and flowed ,stopped flowed stopped as it should....if a valve is stuck open then fuel would be pulled into the cylinder in excess as well correct hence shutting off the fuel would help the situation as well ..?? ..thanks for your input I'm knowledgeable on the subject just not a mechanic it helps to pick your brain ...
Expert:  Curtis B. replied 7 months ago.
Simple enough to remove the rocker cover and check the valve clearance. .004 to .006 inch.
Customer: replied 7 months ago.
I'm gonna do that this evening I've never messed with valves before I'm assuming just a feeler gauge and some alan wrenches to adjust check them ?...
Expert:  Curtis B. replied 7 months ago.
yes, on Kawasaki, I think all you need is wrench and feeler gage.
Expert:  Curtis B. replied 7 months ago.
I think your's will be the same as this one.
Customer: replied 7 months ago.
Yep sure is it .. the rocker arm was completely off of the valve it was so loose so it wasn't opening at all just dumping fuel w no air so it wasn't burning ....question what kind of damage could this have caused the little bit of starting or attempting to start that I did anything I should replace check or anything otherwise what do you think ???
Customer: replied 7 months ago.
And it wasn't like the link just a nut and set screw on top of the rocker arm ....I'm wondering as well about the push rod just flying around while I was cranking it maybe if it bent it do I just pull it out and put a new one in if I replace is there nothing on the other end I can pull off if I pull it out to look at it I'm not sure??
Expert:  Curtis B. replied 7 months ago.
Take pushrod and roll it on a flat surface ,if it is bent, it will show it. It should not have caused any damage, if not, bent, I would slip it back in and adjust the valves. The bottom end is just a cup to keep it centered on the lifter.
Customer: replied 7 months ago.
Thanks bud I appreciate all your help once running I'll come back to give you an A....I definitely learned sumn from this one and I think so did everyone I spoke with about it...lol
Expert:  Curtis B. replied 7 months ago.
OK> thanks