Merc 350 problem

[Chinewalker]

Re: Merc 350 problem

The trim tab comes off by undoing a cap-screw accessible through the hole directly above it on the motor leg. You'll need (I think) a 5/16 or 3/8" Allen wrench to undo it. Mark where the fin of the trim tab is oriented so you can get it back in the same position...<br />- Scott

 

[tsutter]

Re: Merc 350 problem

OK, got the water pump rebuild kit and proceeded. Everything pretty much went alright, but a few concerns popped up:<br /><br />1.) I got the water pump cover back on with the new impeller underneath and then realized that I didn't lubricate the inside of the water pump cover (got sidetracked with company stopping by). The manual says to use a multipurpose lubricant to do this. Can I still take the water pump cover off, remove the new gasket and lube up the inside of the water pump cover without screwing anything up? Also, is vaseline (petroleum jelly) an adequate "multipurpose lubricant"?<br /><br />2.) I was unable to get the lower unit back on. The manual states that the splines on the driveshaft need to line up with the splines on the crankshaft, and this can be accomplished by turning the flywheel while at the same time pushing the lower unit up. When doing this should the unit just "snap" in (meaning can you feel the thing fit into place)? Should the controls be in forward gear when doing this, or neutral?<br /><br />Thanks in advance for your replies.

 

[tsutter]

Re: Merc 350 problem

Should mention a couple more things:<br /><br />When I took the water pump apart, I noticed some pieces off of the old impeller, but for the most part the old impeller stayed intact. I also noticed some extra rubber pieces that looked to be from something else (???) and a small pin. Any ideas as to what these may be from?<br /><br />Also, in my water pump rebuild kit, there were 2 gaskets and a plate, an impeller, a centrifugal slinger, a stainelss steel key, and one fiber washer. There was also a bottom and top driveshaft seal. These were not on the driveshaft when I pulled it as part of the lower unit from the exhaust housing (there was just one fiber washer). Do these need to be on the driveshaft when I try to put the thing back together?

 

[tsutter]

Re: Merc 350 problem

^^ bump ^^

 

[tsutter]

Re: Merc 350 problem

^^ bump it again ^^

 

[Chinewalker]

Re: Merc 350 problem

Hi TSutter,<br /> Anytime an impeller comes out in more than one piece it's a good idea to make sure you've got ALL of the pieces. Kinda like piecing together a puzzle to account for all of them.<br /> As for lubing the impeller, don't worry too much about it. If you want to, that's fine, but it's not a bad thing unless you're planning on running the motor dry. I prefer to use a silicone spray lube when I want to protect the impeller.<br /> Ahhh, the true test awaits. Getting the lower unit back on is one of the most frequent complaints on the board. Three things have to happen. First, the driveshaft has to mate up with the crankshaft. Second the shift rod has to line up with the shift coupling. Third, the water tube has to line up with the waterpump housing. I find that a colorful vocabulary helps on this one. I've found that if I have both the lower unit and upper shift in neutral (prop spins freely) when I assembly it, it tends to go much easier. <br /> One o-ring goes in the groove at the top of the driveshaft. A heavier rubber piece sits at the base of the driveshaft on top of the waterpump housing. There's a rubber grommet inside the water pump housing outlet where the water tube seats. There's a gasket on the underside of the waterpump plate, as well as one on top, between the housing and plate. There is a seal in the top of the pump housing if it's a metal housing. There's also an oil seal in the waterpump base and a gasket between the base and the gearhousing. That about covers the misc. gaskets, seals and o-rings you'll find on your motor...<br />- Scott

 

[tsutter]

Re: Merc 350 problem

Thanks Chinewalker for the info. Of course, I've got another question (always been a problem of mine). As far as putting the lower unit back on, you mentioned that you have better luck if the controls are in neutral and the lower unit is also in neutral. How do I get the lower unit in neutral?<br /><br />secondly, there really was only one piece of rubber that ripped off of the old impeller. I found that, but I found additional rubber pieces. Could this be from something else (I think I accounted for all of the gaskets, etc.. EXCEPT the grommet for the water tube)? Or could it have been left over from one of the last times the impeller was changed?<br /><br />Sorry to be so persistent with the questions - just want to make sure I have my bases covered.<br /><br />Thanks everyone for your replies.

 

[NMplayer]

Re: Merc 350 problem

Hey guys, Havent been around for awhile.<br /><br />OK, I don't think the rubber pieces are a huge concern as long as you put all the new parts where they ought to go in the kit. Some kits are for multiple applications and you may have more parts than you need.<br /><br />Lubricating the impeller is probably not a huge deal as long as you made sure all the splines were going the right direction when you put it in.<br /><br />Look at the top of the lower unit where the shift shaft connects. You can turn the small shaft down there to shift the gear case. It is very important to make sure that the remote control shifter and the lower unit are in the same gear when you put it back together.<br /><br />Getting the lower unit back on is a trick. Make sure you get the water tube and shift shaft lined up good. Then have someone move the flywheel back and forth while you push up on the lower unit. It isn't easy but if you mess with it long it'll eventually go back in.

 

[NMplayer]

Re: Merc 350 problem

Oh yeah. You really need to invest in a manual. They are worth their weight in gold. I got mine right here at iboats.

 

[tsutter]

Re: Merc 350 problem

Thanks NMPlayer. Actually got a manual, but looking to fill in the gaps a little. As far as the lower unit going on, I wasn't sure how tricky this thing could be. Last night I tried several times to turn the flywheel and push up on the lower unit at the same time, but no go. Gave up cause it got dark (actually had only been working on the whole project for about an hour, but it was almost pitch black here by 7:30 p.m. Decided to pack it in for the night).<br /><br />Anyway, the manual stated that there should be a grommet connecting the water tube to the water pump outlet. When I took the lower unit off I noticed that this grommet was not there. I don't think that it was in the water pump rebuild kit either (just two sets of top and bottom driveshaft seals, in addition to the water pump components). I'm going to head down to the local marina and check to see if I can get this part. Any other places where I may acquire this particular grommet or seal?<br /><br />Thanks again for the reply. I must say this forum, in addition to having a manual, is a great way to learn about outboards!

 

[NMplayer]

Re: Merc 350 problem

Sort of seems odd to me that the grommet in the pump cover was gone. Oh well, stuff happens. You can probably get the grommet from the same place you bought the kit. Its possible that you might have to order a whole new pump cover with the grommet, but I don't think so.

 

[tsutter]

Re: Merc 350 problem

Hey NMPlayer and all:<br /><br />Well, it turns out that the grommet is actually there. I was thinking it would be removable as the manual states on page 9-66 (seloc volume 1) to push a new water tube seal onto the water pump cover after fastening the screws on the water pump cover and installing a new centrifugal slinger.<br /><br />Will post once I try again tomorrow to install the lower unit.

 

[tsutter]

Re: Merc 350 problem

OK, I gave it a try and almost got the lower unit back on. The driveshaft splines match up with the crankshaft splines nicely (when you turn the flywheel the prop turns), the water tube is all the way in, but I can't get the shift lever fitted to the shifter on the lower unit for the life of me. I get the two main bolts slightly tight, just enough to hold the lower unit to the exhaust housing so I can test the shifting. I shift and the shift lever works fine for a couple of tries, but then I get major resistence when I try to shift in to forward after 3 or 4 times. Does anyone have any handy tricks for getting the shift lever and the shifter to fit together? Should I have the entire lower unit on (all bolts tightened) before I try to shift? Would cleaning out the areas where the shift lever and lower unit shifter join together, and then lubing these areas help?<br /><br />Any assistance would be appreciated. Thanks in advance for your help.

 

[tsutter]

Re: Merc 350 problem

bump

 

[tsutter]

Re: Merc 350 problem

Hello everyone:<br /><br />OK, the thing is still not on, but I do have some more information to report. It appears this whole time that the lower unit was stuck in a gear. When I turned the shifter on the lower unit for this whole time, I really was only in one gear. The prop would spin clockwise this whole time (with a clicking noise) - is this reverse? I thought reverse was when the prop doesn't turn either way (???). When I forced the shifter to turn counterclockwise past the last stop, it locked into a detent. Then the prop spun freely in either direction (no clicking noise). This I determined to be neutral. However, I could not turn the shifter on the lower unit further counterclockwise. Do I have to force it further counterclockwise in order to snap it into forward?<br /><br />Chinewalker, you mentioned in a previous reply that its best to have the controls AND shifter on the LU in neutral to get the lower unit on. I can get the LU in neutral, but then the bottom shift coupler (the retainer?) needs to be rotated. If it is rotated, the top shift coupler (boot?), which has metal flanges on the sides, can fit into the metal guides on the exhaust housing (thereby allowing the LU to slide onto the exhaust housing so I can secure the LU bolts). Is this what I should be doing?<br /><br />THanks again everyone.

 

[tsutter]

Re: Merc 350 problem

OK, I sort of have the LU on. LU was in forward and controls were also in forward. When turning the flywheel, the prop turns. The shift shaft appeared to slide up and down smoothly on the LU shift rod. When first operating the remote controls, things seemed to go smoothly at first. I tightened up the two main bolts so that the LU was completely mated and somewhat tight against the intermediate housing (I didn't tighten the back two bolts). I then tried to shift. Everything fine at first (first few tries), but when I then shifted from neutral to reverse on the remote controls, I heard a click in the lower unit and from that point on I got resistence as I tried to push the controls back into neutral and then forward. I still can push them into these gears, but I get resistence. Not only that, but now the shift shaft does not slide nicely up and down the LU shift rod. Instead it appears jammed. Any idea as to what is going on, and how I can fix it?<br /><br />Gracias everyone.

 

[Chinewalker]

Re: Merc 350 problem

Hi TSutter,<br /> Are you shifting with the motor running? Shifting with the motor NOT running should be done cautiously, as the shift cogs on the clutch dog may not align correctly with the mating cogs on the gears. This can give the impression that the motor isn't shifting correctly.<br /> Ratchet sound - Forward<br /> Free-Wheel - Neutral<br /> Lock-to-lock - Reverse<br /> <br /> Lower unit is spring loaded into forward gear so if the shift rod rotates too far and freely, it's likely in forward and you're coming around the other (no detented) side of the shift cam.<br /><br />- Scott

 

[tsutter]

Re: Merc 350 problem

Hi Scott<br /><br />Thanks for the reply. I am shifting with the motor not running. I wondered about that a little bit ago. Will the LU not shift unless the motor is running? It seems that no matter what I shift into when the motor is not running, I have nothing but forward gear (prop turns clockwise). Would this change if I had the motor running?<br /><br />Also, someone else mentioned that I may have my rev lockout incorrectly installed. I don't know what this is. <br /><br />All I know is that when I loosen the two main bolts again and drop the LU just slightly, it seems to free up the shift shaft and it starts to slide freely again. This is what I did over the lunch hour. I checked the shifting while the motor was off just ONE time and decided to leave it alone. I plan on putting everything back together and starting her up. Is it alright to shift into either gear with the motor muffs on? (Even if its into very low rpms only). Just enough to see if the motor is shifting correctly? If this isn't a good idea, what can I do to check if its shifting correctly?<br /><br />Any additional info on the rev lockout would also be appreciated. Thanks much for the replies.

 

[tsutter]

Re: Merc 350 problem

Well, I think this thing is finally finished. Had a friend come over to help, and we fiddled with this until we got it right (I think). We had a lot of trouble coupling the shift shaft to the LU shift rod, but when we last checked it, we got neutral on the controls, and the prop spun freely in both directions. Remote forward, prop rotated clockwise with clicking. Remote reverse, prop spun with clicking in either direction, but when the controls were brought nearly all the way back, the prop didn't spin in either direction. The controls seem to operate easily. Lastly, I can hear the gears engage with each movement of the shift lever. We went through the F-N-R sequence a few times then decided to call it a night. Tomorrow, I fill her up with LU oil and try the new impeller. <br /><br />Thanks again y'all for all yer help in getting the LU on.

 

[tsutter]

Re: Merc 350 problem

Hello everyone:<br /><br />Well, it's working. Thank goodness - I would have hate to have seen this thread go too much more! <br /><br />I filled the LU up with LU gear lube. Connected everything back up and tried to fire her up. At first, it would start and then bog down in idle and then quit. Tried this a couple of times, scratched my head and then took the cowl off. I noticed that the choke plate was shut this whole time, which explains pretty well what was going on. I pulled the plugs and cleaned the ends (which were fouled up a bit), and then reinstalled them. I then turned the choke lever to open the choke plate and started her up. Purred like a kitten and about 20 to 30 seconds later... voila... a telltale stream. It was BROWN. Really looked as if it was pretty clogged up. I ran it about 10 seconds after I started to get the telltale. And it was a good strong stream too. So, the telltale's working, and I'm heading out to the bay to see how the shifting is working.<br /><br />But I still have a couple of questions:<br /><br />1. I noticed another type of vent, located about 1 inch up and over the LU vent hole, and many more inches above the LU fill hole. This vent was labelled "flush". What is the purpose of this vent? I noticed last night after I had flooded it out a couple of times that when I opened this vent, out spilled (I think) water and gasoline! Is this normal?<br /><br />2. I also want to check the compression in the bottom cylinder just to be sure. If you remember from about the 3rd or 4th reply to this thread that I was able to check the compression of the top cylinder - 120psi after 4 key turns. I was unable to get at the bottom cylinder to check the compression because the bottom cowl is in the way. Is this easy to remove? Are there any adapters that I may be able to pick up that would allow my compression tester to thread into the bottom spark plug hole without me having to take the bottom cowl off. My thinking now is that cylinder is probably fine, because it was idling so well, but I want to be sure.<br /><br />Thanks again everyone for your help.