175 two stroke stumbles on acceleration.

[Walt_S]

My 175 stumbles around 1400 rpm after that it's good until I push it above 4200. Then it pukes on itself and drops in rpm. It doesn't shut completely down. I'm thinking fuel pumps. Any ideas? Thanks

[TownsendsFJR1300]

Can you post some more information on the engine?

Year, model, carbed, FI'ed?

[Walt_S]

It's an 89 175 carbed good compression across all cylinders. Filters are clear, no water or debris.

[TownsendsFJR1300]

Has the engine sat for awhile?

Sounds like the carbs are varnished up. It doesn't take much to clog the jets.

I'd pull the carbs off, PULL and INSPECT all the jets and make sure you can see light thru them. Just spraying carb cleaner DOESN'T COUNT..

Here's the parts fisch for the carbs;

http://www.boats.net/parts/search/Ya...TOR/parts.html

You want to pay special attention to the MAIN JET, the IDLE jet and the nozzle(that usually has smaller holes sideways in it)

[Walt_S]

Engine has not been sitting, uses non ethanol fuel with additives. Ran fine when I launched in the spring.

Backed out the fuel pump bolts and squeezed the primer bulb (engine off) and fuel dripped down the back of the pumps. Thought this might be an indicator of a bad diaphragm or is that normal? Tightened the bolts , started engine and it ran fine. Sea trial today. Plugs are clean, no carbon , not wet from excess fuel.

[TownsendsFJR1300]

The fuel pump shouldn't be leaking, check the internal diaphragm for failure..

[Walt_S]

Thanks.. I guess I'll buy two pumps or kits

[TownsendsFJR1300]

The pump(s) work off of crankcase vacuum..

That lil bit of fuel your seeing(with the pump off), its getting sucked into the crankcase, and into the fuel mix eventually.

Please post back.

[Walt_S]

Thanks Scott. I'll get two kits tomorrow and rebuild.

[99yam40]

if they are not leaking out of the pulse port then the diaphragm should be fine.
Possibly it is leaking out of where you loosened the bolts causing the gaskets not to seal properly

You need to find out where the fuel is seeping from.

[Walt_S]

Thanks
Now moved down the list, the riding mower took a dive this afternoon.
Considering draining the fluids and taking it out and start my own artificial reef program.

[99yam40]

Hopefully you did not forget to check the oil before mowing.
Had a guy from the church I go to ask me to have a look at his after it quit.
Oil all over the place on the outside and metal flakes on oil on dip stick.
I told him it was toast and did not even try tearing it apart to see what all was bad

[Walt_S]

Drive belt on the mower. Years ago my wife was mowing and called me at the boat to tell me it stopped. I got home about an hour later and checked the oil. EMPTY. Motor locked up. Filled it with oil and took a socket and strong bar the nut on the shaft. Rocked it back and forth and it broke free. Started it, ran for 5 minutes, then changed the oil and filter again. Ran fine. Three weeks later she called again and said the carburetor fell off. When I got home it was sitting in the middle of the lawn. I opened the cowl and the STARTER was hanging by the power cable. It seems that a rod broke and blew a hole in the block and knocked the starter off. A new motor fixed the problem. Imagine that...

[Walt_S]

Mower fixed and so is the motor.

Rebuilt both pumps even though only one leaked, Starts and runs like it should.

Thanks for the help.

[TownsendsFJR1300]

Congrates and thanks for the update!