very frustrated out of answers 18 hp Vanguard in MaxIV

[westkymaxiv]

when it rains it pours.
all of a sudden my Max IV started running rough. My neighbor said I had "Green gas " in it get it out. It was back firing and had no power. I drained the gas tank put fresh gas in it SAME thing. So i decide i need to clean the carb again. I did this a few months ago when it was surging and made it run great. So I clean the carb.. Take the jet out and clean it ect. Put it back together and dont realize i have dropped a bolt that has wedged between the flywheel. When i hit the key the starter turns a little then nothing. I take the rope crank cover off and there the bolt is wedged between the top of the flywheel. I get the bolt out try the key nothing. I try the rope it is cranking over but gas is pouring out of the carb, It back fires and actually catches top of carb on fire a little. This was all yesterday.
So o come home today decide to try some more. First i fear alost of gas in engine so i change the oil and filter. I then take carb back apart and clean. I then try to start with screw driver across solenoid. it trys to once but could never get it to turn over with the screw driver on the solenoid again. So I try to start with rope again. Gas is spewing out the carb and it trys to start and cathes on fire again.. Im at a lost i dont know where to go from here

[kghills]

I had a similar experience without all the gas or fire though with my Max IIs 18HP years ago. It turned out to be a bent pushrod. Its pretty easy to pop the valve covers to check.

Hope this helps, Keith.

[westkymaxiv]

well i got part of the problem better last night. the Tang that holds the float somehow got bent way out of position. I dont know if a back fire could have caused this or not. But I bent the tang down to allow the float the drop down and shut the fuel off like it is suppose to. Im still not sure how to get that adjustment exactly right. It starts and runs decent now. But looks like some exhaust coming out of the carb to me. And it hickups about every 5-7 seconds. Sometimes a flame shoots out the carb. usually when I first pull the rope a flame will shoot out the carb. Any suggestions?

[Bazooo guy]

Take the float out and shake it and see if you hear anything inside.....it could be filling with gas and not floating to close the needle.
When the engine locked up it could have sheared the flywheel key and the timing is off....check that also.

[westkymaxiv]

i think the float issue is solved. it was bent badly out of adjustment. how this happened i dont know. But I plan to try to check the flywheel out when I get home. I wonder if it is gonna take a special puller to get it it off?

[westkymaxiv]

ok i took the OHV cover off the front of engine. the pulled the rope very slow. the valve... closest to the wheel moved up and down the one closest to the center of vehcle isnt moving. i took a flashlight and looked in the hole and the pushrod was out of position. it doesnt appear bent. is this just out of position? is it easy to put back in place or is it somehow broke?

[brushcutter]

Loosen the adjustment screw and remove the push rod. Wipe off the oil and on the flattest surface you have, lay the rod and roll it while watching for deflection, (up and down motion), this will tell you if it is bent, if so, replace it with new. If none, put it back in and adjust the valves on both cylinders. You should be good to go on that. For the flywheel, if it moved enough to shear the key, it should come off fairly easily.

[kadookid]

If you normally run regular unleaded and then dumped some alcohol gas in it, ran the machine for awhile and then parked it for a month or so what I've seen happen several times on these small engines is the alcohol loosens up the varnish and it builds up on the valves and guides and while the thing is parked the varnish gets so gummy that later when you try and crank it over to start, it will actually bend the push rods sometimes just enough that it won't run right, and once in a while it won't run at all, just an idea mike.

[westkymaxiv]

i checked the flywheel it was fine. i talked to a highly recommended mechanic by a few sources and he told me the head would have to be replaced. I described to him what I saw. He said the fact looking at the springs around the valve .. i think being pushed up higher that it would have to have a new head. Does this not sound right???? I thought maybe I could just put the pushrod back in but he said it would just do it again??? He said he could sell me a used head for $40 and complete the work for $150.

[kghills]

Without seeing it or at least a picture of what you are describing this is what I would do. Unbolt the rocker arm and pull out the pushrod. You can check it for straightness or just replace it, they are really cheap. Aluminum pushrods are used on the intake and steel pushrods are used on the exhaust. Push up and down on the top of the valve to make sure it is not stuck in the guide. If it is free, put the pushrod in, the rocker arm back on and adjust the valve lash.

Keith.

[jerseybigfoot]

gummed up /sticking intake valve stems from varnished up gas will allow the push rods to fall off the rocker arm. Just put them back like brushcutter posted. eventually the gummed up valves will loosen up. Some WD40 sprayed on valve stems an into the intake may help while you spin the engine. the engine will back fire if the intake valve stick an doesn't close. rotate the engine so the piston is at bottom dead center so you can work the valve in and out to make sure it seats.

[westkymaxiv]

he had me look at the springs. he said look inside the springs. If one side is pushed up higher than the other he said it was a waste of time and money to replace the pushrod . I told him the side that has the rod out the valve is higher in the spring than the other side. He said well i can tell you by that it has to have a new head. Im just trying to get educated i appreiciate all the help you people are giving me.

[jerseybigfoot]

Needing a new head does not sound right. You have to burn up or drop a valve seat to need a new head. I had the same problem you describe but it was sticking valves. if you bent a valve that's a different matter. you still would not need a head, but a valve replacement. removing the head is easy once you have the cooling tins off the engine. especially on a Max 4.

[westkymaxiv]

you just rang a bell.... he said the fact the one valve was pushed up higher told him i had " dropped a valve seat" so I would have to replace the head.

[westkymaxiv]

ok so this morning i decide to look under the other valve cover. The push rods were on but I was seeing the same thing the guy described as his method of telling the valve seat had dropped. I thought hmm. I then pushed down on the spring on the valve that had the pushrod out. I then pulled the pushrod out. I then checked it as you all said.. NOT bent. I pushed the valve back down and popped the pushrod in place. Put it back together. Wow no more back fire or flooding !!! there is a hesitation. But I bet the valves have never been adjusted. And I may have the float adjustment out now. Im a little slow and hard headed but I think I finally did what you guys told me to do and I dont think it needs a head now either. Now if I can only understand how to adjust the valves.!! thanks for all your help! by your silence after the last post i could tell you all knew i didnt understand what I was doing lol and you were right!