Newbie needs help - Locked motor?

[mfoster430]

Hey guys. Like the title says, I'm new to amphibs. I have a 1996 Max IV with the 18hp Briggs Vanguard V Twin. I bought it used a couple of weeks ago from NC. I played around a little for a couple of hours when I got it home and it ran great. Today I took it to my buddy's place who has a lot of land to just get myself used to the way it works. It ran perfectly for a few hours with me getting more and more comfortable with it as I went. Finally after really getting it going for a few minutes, I heard a loud rattling sound coming from the motor and it died. I immediately tried to start it again but just a click. It wouldn't even offer to turn over. My buddy towed me back to his garage and we looked at the motor. It's locked up bigger than crap. The pull start won't budge. We took the plugs out hoping it would free up but no luck. I'm puzzled. It had a fresh oil change so it's not low on oil. Any advice or suggestions? If this problem has already been discussed somewhere else, I apologize. If so could someone direct me to the thread? Thanks for your time. I just need to know which direction I should take.

[Mike]

Welcome to the forum. When you pulled the spark plugs, was there any gas noticeable? Sometimes, once these motors cool down, they will free themselves back up. I would start by giving it time to completely cool tonight and see if it will at least turn over tomorrow with the plugs still out. You may want to put a tablespoon of oil down in the cylinders as well while the plugs are out.

Even though it recently had an oil change, I would still check the oil level and then drain it and check for any signs of metal, etc.

As to what caused the problem, I can't help there. Perhaps some of the engine gurus will chime in later.

[mfoster430]

Hey Mike. Thanks for the reply and advice. I didn't really notice any gas when I pulled the plugs. I did check the oil level right after it happened and it was fine so I can rule that out. The only issue I had all day was every once in a while it would quit like it was out of gas. It had a full tank. I would have to choke it and start it up again. It only did that a couple of times and it would intermittently idle funny. I checked the in line fuel filter on the gas line. It looked to me (again, I am a novice) that there wasn't enough fuel going through the filter. It was barely up to the bottom of the filter. I don't know if that would have anything to do with the motor locking up. I haven't had a chance to fool with it today. I had to work. I'll check it this week. As stated before, any ideas would be greatly appreciated. Thanks all.

[ARGOJIM]

Holding the clutch see if it will turn backwards, sometimes a bolt will fall in the flywheel area and jam up an engine, it is also possible the flywheel magnets let loose locking on the stator.
If it does turn see if both pistons are moving, that should give a clue as to internal or external issue.

[mfoster430]

Thanks Argojim I'll give that a try when I get the time to check on it this week. I'm hoping it's an easy fix and not something that is going to have me motor shopping. On the other hand though, it would be a good excuse to get a bigger motor.

[wheeler]

mfoster
I had a piece of metal come off of the choke linkage and lodge down into the flywheel. It locked up the engine tight. I made sure I did nothing more, other than move the clutch by hand slightly to see if I could get it to turn.
You might want to pull the housing cover off of the motor and look around the flywheel to see if you can see anythings jammed in the flywheel. Just as Jim said, the magnets could of pieced off or something could've got jammed in there. Hopefully it's that easy and not an internal piston thats blown. If the clicking sound was bad enough I would be concerned that the piston rings took to breaking. And as Mike said, by draining the oil you might see metal in the oil or feel the metal shavings between your fingers in the oil. Hopefully that's not the case.

[Toys4Me]

I've had pieces of broken starter gear get behind there and jam it up.

[Nubs]

Flywheel Magnets also..

[mfoster430]

Well guys...I have good news. I took the Max to my buddy that's a mechanic. There was a bolt from the cargo rack that sits above the engine that had come loose and fell into the engine and lodged itself in the flywheel. After taking it out and putting everything back together, it runs like a champ. That makes me very happy. I'm glad it wasn't anything serious and I'm even more glad it didn't do any permanent damage. So now the only thing I need to figure out is the lack of fuel problem. It still wants to die every now and then like it's out of gas. All I have to do is choke it and it fires right back up. I'll start with the fuel filter and go from there. Thanks to everyone for all the suggestions. Happy riding!!

[wheeler]

Glad to hear that. It's a relief when you find the problem and "the problem" hasn't done any major damage. Have a good time with that thing.

[Outlaw1]

Yep, there's a motocon for just about everything. Good for you

[dollar bill]

Hey mfosrer ,glad to hear you got luckey,I would look into nylock nuts 4 that rack next.on the cutting out problem, my max 4 did that when I first got it, had the carb rebuilt, then it only did it on a big bump or steep hill,so I took it back to my mechanic, he redid the rebuild,its been great ever since, I've not had a vanguard carb apart myself, but I wonder if there is a snug fit in there that's got to b juuust right,crimped gasket,bent tab,pin or something.