2hp Yamaha seized up! How do I drop the lower unit?

steviecops

Chief Petty Officer
Joined
Oct 3, 2003
Messages
585
Hi<br />I've just got hold of a little 2hp Yamaha, (2B GA1 102994), which came as part of a job lot. It is seized up, and from what I can make out, it's seized at the gearbox.<br /><br />I tried to remove the powerhead first, but it won't come off! Then I tried to get the lower unit off, and that won't budge either. The prop won't turn, but when I rotate the lower unit,(only able to rotate about 30 degrees), the flywheel rotates with it.<br /><br />So if the flywheel rotates, it can't be the piston that's seized, it has to be the gearbox.<br /><br />Can anyone tell me how to get the lower unit off? I've removed the 4 bolts and it won't come off! Feels like something else needs to be removed before it will drop.<br /><br />Thanks in advance<br />Steve
 

self taut

Petty Officer 3rd Class
Joined
Jun 25, 2004
Messages
86
Re: 2hp Yamaha seized up! How do I drop the lower unit?

first off look for hidden bolts.the engineers loved hiding those things. makes it a pain.you may also try driving a thin piece of metal through the seam.use caution and dont hit too hard.you just never know what might break.an old putty knife works well.most of the time it is the seal or gasket which is holding the parts together.dosent seem they would do that so well but they do.after breaking the seal look for pry locations. odd looking flat spots or flat extensions around the seal they allow you to get a berrer lift without damage.a good flat screwdriver works.whatever you do dont try to horse it.a wiggle and a pry here ...a wiggle and a pry there.it will come off just be patient with it.you can also use a good penatrant to soak the gasket, causing it to soften and break apart easier.( if it is a felt or paper gasket anyway)good luck
 

steviecops

Chief Petty Officer
Joined
Oct 3, 2003
Messages
585
Re: 2hp Yamaha seized up! How do I drop the lower unit?

Thanks self taut<br />There is quite a big gap there, and I've tried the usual screwdrivers and pry bar, but it doesn't want to come off.<br /><br />All the bolts came out really easy, which makes me think this motor hasn't seen salt water, so I'm a bit surprised why the lower unit won't drop. I'll check for hidden screws, but I'm sure I've got them all because of the gap that has opened up, it's about half an inch.<br /><br />By the way, I've managed to get the prop turning by spraying penetrating oil around the propshaft seal, it's stiff, but it's turning. The piston is moving freely with the flywheel, and it sounds like the compression is good.<br /><br />I still want to get the lower unit off now though, to change the impeller. If anyone has one of these and knows of anything else that has to be removed to drop the lower unit, please let me know!<br /><br />Thanks again<br />Steve
 

self taut

Petty Officer 3rd Class
Joined
Jun 25, 2004
Messages
86
Re: 2hp Yamaha seized up! How do I drop the lower unit?

ok another idea.although im not real familiar with your peticular motor.have you looked to see if there is something hanging up on the shift linkage?as i said not real familiar with your motor but most motors i have delt with the lower unit wont come off if the cotter pin isnt taken out of the link.just an idea
 

steviecops

Chief Petty Officer
Joined
Oct 3, 2003
Messages
585
Re: 2hp Yamaha seized up! How do I drop the lower unit?

Hi self taut<br />I thought of that, but the engine is direct drive and doesn't have a shift linkage.<br /><br />I haven't got a manual for this engine, but from what I've read about other small direct drive outboards, the lower untit should drop off when the bolts are out.<br /><br /><br />Thanks<br />Steve
 

self taut

Petty Officer 3rd Class
Joined
Jun 25, 2004
Messages
86
Re: 2hp Yamaha seized up! How do I drop the lower unit?

well i'm outta ideas.not used to smaller engines.at least not repairing them.best of luck to ya.
 

steviecops

Chief Petty Officer
Joined
Oct 3, 2003
Messages
585
Re: 2hp Yamaha seized up! How do I drop the lower unit?

O.K, I finally got it off using wooden wedges and penetrating oil. The drive shaft was corroded on at the powerhead.<br /><br />The impeller housing was one solid lump of rust and corrosion, had to cut it off with a hacksaw.<br />I still had to take the gear mechanism out to get to the impeller though.<br /><br />While I had it on the bench, I removed the powerhead and took the head off. Every water passage was solid with salt, sand and corrosion!<br /><br />Piston and cylinder still in good condition and compression good, so this little engine should breath again soon ;o)<br /><br />Thanks<br />Steve
 

self taut

Petty Officer 3rd Class
Joined
Jun 25, 2004
Messages
86
Re: 2hp Yamaha seized up! How do I drop the lower unit?

good to hear it.enjoy the rebuild
 
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