Briggs 18 twin

[RedWolf]

Hey guys. I have a briggs flathead twin (422707)(1522 01)(9306245A) and what it does is every month or so it locks up.I check the oil and its fine and i change the oil every 50 hours.Once i get it free it will fire up and smoke lightly for about a min then clear up and run fine till it does it again. What do you guys think is going on?:confused:

[Restrorob]

If there is no bottom end noise once you get it running again I believe I would pull the heads. Check for excessive carbon build-up on the pistons and heads as it could be breaking loose and locking it down. I have ran across this a couple times on these older L-heads.

[khouse]

could he that the cylinder is fillled with fuel (carb needle seat) or oil (sump overfilled) does your oil smell like gas? next time it happens remove both plugs and crank over. first see if this frees the engine then see if any fluid blows out the plug holes.

[Restrorob]

next time it happens remove both plugs and crank over.


ALWAYS make SURE you ground both spark plug leads before doing this or you could have a fire on your hands.....

[khouse]

restrorob, good tip.

[RedWolf]

Thats the funny thing.The oil doesnt smell like fuel and when I get it free and turn it over the cylinders are bone dry. I will check for carbon and will let you guys know what I find.:waving:

[khouse]

maybe you have a bad sement on your comutator. have you checked the starter armature?

[Restrorob]

maybe you have a bad sement on your comutator. have you checked the starter armature?


Since you brought that up, It could be a worn starter gear hanging in the flywheel.

[khouse]

that's right restrorob.

[GearHead_1]

If this happens when running, I too would suspect carbon has built up on in the combustion chamber. It gets hot, expands, touches the piston and the engine shuts down. I've seen this happen a lot on the old 5 h.p. L Head Briggs motors and once on the same motor you have mentioned.

[RedWolf]

ok guys. Pulled the heads and the heads and pistons where loaded up with carbon. I cleaned every thing and put the old beast back together and she fired right up. Thanks for all the help guys.I dont think the last owner did anything to the engine.:waving: