72 Merc 800 shifts hard and reverse makes noise?

As my handle says I'm a boat noobie so I have a few Q's <br /><br />I took my 72 Starcraft 18' aluminum runabout with the 72 Merc 800 80 HP out to the lake for the first time last weekend and was pleasantly suprised. She started right up and ran great for the whole hour I got to be out (it was really windy).<br /><br />The only problems I could tell were it shifts very abruptly, push the shifter all the way forward until the motor starts to rev a little and it "pops" into gear. Reverse did the same and once it started to make a grinding noise while reverse was engaged, or maybe not engaged all the way? It never made this noise while in forward gear. How bad is the diagnosis? Does the shifting cable possibly need adjustment or does it sound more serious than that?<br /><br />I changed the gear oil just before I went out, should I drain it and look for problems there also?<br /><br />What other maintanence should be done on her and how do I get the cowl off?

Re: 72 Merc 800 shifts hard and reverse makes noise?

on the front of the motor center plate near the botttom is a black knob, push in and turn, behind it a spring clamps you release. the top comes off by releasing the clamp on the front. i know this boat is new to you, but do you have any history on it? when was it last run, etc? if your cables a oringinal the could be streched, or about to break, thus not engaging you gears properly. obviously you are not familar with merc outboards. are you mechanicly inclined? not being rude. need to know your experience, to better guide you. suggest your the the engine specific manual for you motor, you will need serial # off motor and got to 'oldmercs.com'. they are pricey, but making it your best friend for a week or so, you will be more knowledgeable about your motor. mistakes can be very costly. get back with what history you have, and we'll go form there.

Re: 72 Merc 800 shifts hard and reverse makes noise?

Thanks for the response, I understand you need info and yes I am new to all boats but somewhat mechanically inclined. I've been an electrician for 13 years and do my own mechanical work on my vehicles like brakes and other minor parts replacing. I have alot of hand and power tools and I know how to use them.<br /><br />From what the guy who sold it to me said, the boat was out once last summer and used frequently in past summers. The gear oil was changed 2 summers ago. When I changed it last week there were no chunks or larger than tiny flecks of metal in the old oil. His dad, who passed away 2 years ago, owned it and used it alot for about 25 years. The cables seem to be original, but I'm not sure. The boat seems to have been taken care of except for the last 2 years.<br /><br />I did sound pretty green asking how to remove the cowl lol. After I removed the cover with the black knob with the spring on it I saw the clamps that hold it tight and they didn't seem to want to open, I asked because I didn't want to break anything, I think she would benefit from some seafoam and some new plugs. <br /><br />Are the seloc repair manuals any good? For half the price of a Merc are they worth getting or should I just get the real deal?

Re: 72 Merc 800 shifts hard and reverse makes noise?

I've also read that the water pump impellor needs to be replaced every couple of years, I'm sure that this hasn't been done, how do you know if it needs to be replaced?<br /><br />I forgot to mention that it will pop out of gear at very slow trolling type speeds also.

Re: 72 Merc 800 shifts hard and reverse makes noise?

Get a manual, Seloc is fine although not model specific. This will help with nomenclature and location of stuff that the gang will tell you check. <br /><br />With the cowling off look at the port (left) side of the engine where the cables connect to the motor. The lower cable is the shift cable and the top one is the throttle. With the shifter in neutral take a good look at everything and note its position. This means the throttle linkages timing advance and the shift slider. Then, with the engine not running put the boat in gear but do not advance the throttle past idle. If the throttle cable has changed position so the cam follower on the carb linkage has moved, you will need to adjust the throttle cable. The Seloc book will tell you all the dimensions that you might need. If you search the forum for Clams post on link and sync that will be a big help too.. To check the shift cable disconnect the shift cable from the slider on the engine and make sure the shift slider is full forward. You can reach down and turn the wheel by hand to see if it is in gear. If it is, adjust the barrel of the shift cable to line up the cable with the slider. If it goes in forward, it should go in reverse, the throw of the cable is not adjustable on the engine end. If it worked last year and no one has had the remote apart it should work now, unless the cable is toast.. If it still jumps in and out of gear and the cable is not sloppy than that is a problem with the lower unit.

Re: 72 Merc 800 shifts hard and reverse makes noise?

I forgot to tell you guys that he told me reverse hasn't worked in a long time. When I got it to the lake I tried it for myself, it went into reverse for a few seconds and then popped back out this is when the grinding noise started. I went back to neutral and then reverse again and the same thing happened. What really worried me was how jumpy forward is. I'll go check what you said to and get back to you guys. I do have a manual on the way <br /><br />Thanks for the info guys

Re: 72 Merc 800 shifts hard and reverse makes noise?

ok. great info. using the search function search for "awakening a sleeping outboard". it sound like you have a cluch dog problem. it's the gear in the lower unit that slides forward and back to engage the gears. you're going to have to drop the lower unit to change the impeller(new waterpump kit). you may as well go ahead and rebuild the lower unit. you definately need to replace the impeller as these engine do not have thermostats, you don't want to toast the engine. the spring clamps on the cowl open from the left to right. you may have to take pliers inorder to grip them if they are rusty and put on too tight. grab the lever on the left side of the clamp and pull toward you. wd 40 may help, then adjust so you can remove them with you hand. good luck. keep us posted.

Re: 72 Merc 800 shifts hard and reverse makes noise?

Had similar problems on a '65 Mercruiser I was restoring. Just happened to be in a '65 18' Starcraft Holiday...coincidence. By the way, when I finished I really enjoyed the boat on the water; on land a bit cumbersome, but in the water, very nice.<br /><br />I completely disassembled the lower unit and learned a lot about how Mercs work. My gears were worn pretty good, but not too much to work for me. Also I could have used a shim (as mentioned a few days ago in the forums....don't remember where) to pick up some of the slack between the driven gears and the drive gear.<br /><br />My problem was finally resolved (adequately) by correct adjustment of the linkage.<br /><br />What it sounds to me like is that in R your clutch dog is not totally buried in the R gear and is hopping out. Probably has some rounded corners which makes the problem worse and then the linkage needs tweaking to push it farther into mesh so that it won't jump out. <br /><br />Besides proper alignment (centered engine position when the control handle is centered), slop in the shifting loop (any part associated with shifting gears within the engine or the boat) can aggrivate the problem.<br /><br />The difference in R and F is that F has a slip clutch; gears are triangular shaped and the dog is spring loaded. The R setup is a rectangular gear mesh; you're in or you're out. Don't remember the involvement of the spring in R....been 15 years since I did the restoration.<br /><br />HTH,<br /><br />Mark

Re: 72 Merc 800 shifts hard and reverse makes noise?

It's funny reverse engages fully on land, the prop won't turn either direction when in reverse, and it seems to shift fine. Under load is another story though. I'm going out now to clean the carbs and adjust the shifting linkage. I'll get back to you guys after.<br /><br />Thanks again guys !!!!