jc56

Can you hold your finger over plug hole while cranking it?You should be able to tell roughly what is going on compression wise.I'm still leaning carb problems.

jem131313

What kind of hissing? Could the spark plug not be seated all the way down and your losing compression around the plug?

bobwhite

well...I aint no mechanic,but it sounds to me like it is blowing out the ehaust and it is back fireing,etc....The sparkplug is snugged up so it isn't that....I will have to investigate it more later today and get back to you...John

dangeroustoys56

My 85 12 HP mastercut has a blown headgasket - i put a used one on, but that let go- could tell a difference nearly immediately - was tons louder and didnt have as much power - the original had been leaking quite a while , could see the soot trail . I just havent been out to pick one up yet ( dont use it much) - should mention mines a flathead briggs tho - i know the OHV motor headgaskets arent easy - have to pull the entire valvetrain to get it apart.

bobwhite

I haven't even been doing anything with it..This darn weather is an issue...As soon as I can get it in my already over crowded garage,I am going to work on it...John

bobwhite

Back out working on the tractor again...Where is a good place to get the fuel shut valve..I love that idea and want to get one of them put on it as well...I took the valve cover off as I wanted to make sure the valves were doing their thing..Looked good...Did I mention that the bowl on the carb was not sealing,even with a new o ring..Leaked gas..Thats why I want to get the shut off valve..
Call me crazy,but I bought a new carburator for it..Got the motor all cleaned up and looking pretty..Once I get the fuel shut off valve I will be installing the new carb..I will try to keep you up to date on my progress....John

wjjones

If you have a TSC in your area they have the shutoff valves also Lowes, and some auto parts stores carry them as well..

jc56

Hey bobwhite.Great to hear ya got it going!!!I sent a pic over on page one about fuel shut off valve location.I put mine right on top of the oil filter......I can turn it on and off without raising the hood.Hope it helps.jc

dangeroustoys56

I just picked up a 98 poulan with a OHV briggs - i test fired the motor, would only run on the gas i dumped in the carb , not gas from the tank - so leads me to believe its the antifire solenoid - when i pull the motor ( its going on another tractor), ill do a carb cleaning and 'fix' the solenoid.

A thing to check/ be wary of on newer motors is the float bowls arent flat on the bottom - the deeper part has to go on the side where the float angles down- if theyre installed wrong - it wont seat fully.


I had one tractor that would leak gas - couldnt figure it out till i had the carb apart for the hundreth time and just happened to angle it tward the sun.... and saw multiple tiny rust holes in it. Changed it with a spare and it didnt leak again.

bobwhite

Alright guys she still will not run right...First thing..The solinode apears to be working.When the key is on you can feel it click open...

I got a shutoff valve,got that installed..With the line off the carburator
I am getting gas so the shutoff valve is working...

When it is all back together the gas will not run to the carburator?

So whats up with that? I put some gas in the carb. and it will run,but
barely..Like it is in a super low idle...I have the needle valve
open maybe 3/4 of a turn...

Fuel tank is half full...If I take the line off,the gas will flow like it is
supposed to...Help me out here,please..I hate to take it to a shop...John

Once in awhile it back fires while trying to start..????

jem131313

Sounds like it's the fuel solenoid on the bottom of the float bowl gone bad and not opening upt to allow fuel in.

bobwhite

Guess,I aint explaining it good enough....Everything is clear from the carb. to the fuel tank..No blockage....There is no gas flowing through the freakin fuel line..If I take the line off the carb. the gas will flow through...But as soon as it is back on the carb,,,NO FLOW...?????

wjjones

The solenoid only opens when there is current if it is bad it could be stuck in the closed position.. The solenoid is the blockage if its not working... it has to open to allow the fuel to get to the carb..... I had one do this, and the plunger on the solenoid was stuck in the closed position..

dangeroustoys56

Sounds like when i slapped a 5HP honda on my 69 wheelhorse( to see if it actually moved under its own power) - i filled the tank, opened the tanks shut off valve, and no gas flowed ( used clear fuel line) , drove me crazy for a 1/2 hour checking stuff, till i saw the shut off valve on the honda carb - opened that up and flowed right on into the motor.

bobwhite

appreciate your replies,but not getting anywhere...I can feel the solinoid valve open when the power is but to it..I guess I will have to look around more..I just dont understand why do gas comes throu the line when it is on the carb..I mean the line is empty...nothing.??????

Bill Kapaun

The fuel solenoid has absolutely NOTHING to do with fuel flow TO the carb.
The "pin" in it blocks the Main Jet when OFF to prevent after fire (back fire) of the engine when it is turned OFF.

IF fuel is not flowing into the carb bowl, the carb inlet is clogged up between where the fuel line connects and the needle seat/assembly.
OR The needle is installed incorrectly and simply isn't opening even thoug the float has dropped.

IF this engine has mixture adjusting screws, open them to about 1-1/2 to 2 turns initially.

dangeroustoys56

To be sure theres no flow issue - replace the section of fuel line closest to the carb with clear fuel rated gas line - ive had issues with fuel filters actually filtering too fine - there was hardly no flow thru the gas line .

A rare instance i had was the tank drain port ( to the carb) on the tank - had actually collapsed when i put a clamp on it - i used a small piece of copper tubing ( REAL small) to keep it from crimping it shut.

bobwhite

It;s been too cold to monkey with it now....What I can not figure is..When I take the line off the carb. let it hang down,gas will flow through..When I put it back on to the carb.The lines stays empty.There HAS got to be some reason for this??
So,come on yoou guys and help me figure this out..Don't tell me I have to go to the shop with it...John

wjjones

Is the tank under the dash?

Bill Kapaun

Copied in part from another forum-
"In 2004 I bought a replacement fuel filter for this tractor based on the model number listed in my manual, 25-050-03 which today maps to new Kohler part number 25-050-22. This filter was an aftermarket that mapped to this same part number and was clear rather than a white opaque plastic. After doing this I had the problem that many in this forum have posted about where the filter appeared to run out of gas and the engine would stall after about 20-30 minutes. If left to set, the fuel would eventually fill back up. The original filter could be put back and this problem went away which pointed to the new fuel filter as being the problem.

I ended up using the old filter since they really don't see much action on a lawn tractor, but this season I decided to find a proper replacement. After some research in the Kohler manuals and having a part shop look up the filter type based on engine model number vs. the part listed in my manual I discovered that Craftsman made a typo in their documentation. The part number 25-050-22 (or 25-050-03) is a 50 micron filter designed for a fuel pump where they also make a 25-050-21 (or 25-050-07) which is a 75 micron filter designed for a gravity feed system like my engine is. "