info on outdrive gear tooth please

bolo789 · Nov 30, 2005

hello guys, i think i might have a problem, today i took the cap of my merc alpha one drive to count how many toot is in there, it has only 20 tooth on both gears . the gear that sits flat facing down, has 20 tooth, that iam sure of, so from learning a lot from this site i tjink it sopose to have 22 tooth. iam i right?? my engine is a 1989 merc 5.7L 260 horse power. so did this gyy rip me of by selling me the wrong drive???? thanks for any info i realy needs to know

Haut Medoc · Nov 30, 2005

Re: info on outdrive gear tooth please

Count again....As far as I know there is no 20/20 gear count on any Alpha gen 1 drives....JK

bolo789 · Nov 30, 2005

Re: info on outdrive gear tooth please

thanks for the come back, i am 200 percent i count 20 tooth on one of the gears looking down from top. the gear that sits side way i might mis the count a little. maybe thats why i did have to go all the way down to a 15 pitch prop to gat close to my wide out rpm. and i still dont get 4600 with me alone on the boat, i know it could be a lot more issue that can cause that. but for now with a v8 engine how much tooth sopose to be on both upper gears?? if i get the right answer i will be happy, thanks

Don S · Nov 30, 2005

Re: info on outdrive gear tooth please

You should have a 1.50:1 gear ratio for your 5.7. That would be a 20-22 gear set, and as stated, there is no 20/20 set. My question would be what kind of problem are you haveing that would make you pull the top and count the teeth? Are you sure your OLD drive had 20-22?

bolo789 · Nov 30, 2005

Re: info on outdrive gear tooth please

as you know don, you help me from the start, searay state that i should be running a 17 pitch , in the begining i start out with a 19 pitch marage, only get 35000 rpm max go down to a 17 about 39000 go all the was down to a 15 pitch ss wich only give me 4200 max trim out, plus only half tank gas and me alone on the boat, thats how i run it all season antil saturday morning i heard a grinding sound when i put it in gear, first it goes in gear then out of gear then back then its good to go. something in that drive is not working good, before i fog the engine i start the engine and at idile it was over heating, so i put in nutral and rev it a little and the temp come back to normal 145 . so i think i read on this forum where someone stated that to make sure i have 22 teeth on the upper gears, thats why i took off the cap don, just touchy feely lol. but iam 500 percent sure the gear that sits down wards in the drive has only 20 tooth, so please help me out on this one guys, did the guy sells me the wrong drive???? my compression test was great all in 140 150s

bolo789 · Dec 1, 2005

Re: info on outdrive gear tooth please

up date on the gears count, one gear has 20 tooth and one has 22 tooth. so good folks is that the was it sopose to be????

Haut Medoc · Dec 1, 2005

Re: info on outdrive gear tooth please

Yes, like I said, you needed a recount....

You have a 1:50 drive .....Exactly what you need.....You have other issues with regard to your boats poor performance......A 15 pitch is too low for that engine/drive.....You should be about 14Dx19P....Something is getting missed....JK

tommays · Dec 1, 2005

Re: info on outdrive gear tooth please

it is a big very heavy boat older boat that is being compared to newer hull designs and who knows how much more it weights now that its had years to suck up water weight brand new trophy 2352 sterndrive fishing boats come with a 15 x 17 prop and dont really go that fast compared to other hulls that are built for speed tommays

DHPMARINE · Dec 1, 2005

Re: info on outdrive gear tooth please

bolo789, I realize this problem has been going on for awhile,and I can only inject two ideas. Never seen the wrong ratio on the wrong engine cause an outdrive problem.I know it's possible,just never seen it. I have seen several wrong ratio matches cause problems with engines. In previous posts have you checked timing,compression and cylinder output ? DHP

bolo789 · Dec 1, 2005

Re: info on outdrive gear tooth please

man oh man. well i did told the mechanic to do the compression test, i was not there when he did, so i am not sure he did one, so this is where you guys are going to help me now. first i have the compression tool in my tool box, i know how to do the wet and dry test, but when you guys said to ground the coil, how do you ground it, the simptom i have all summer long , was after every long run, the engine crank over slow and hard to start, i have to put the trottle wot all the time, so guys compression time. help 1989 searay 220 DA 5.7L 260 THANK

bolo789 · Dec 1, 2005

Re: info on outdrive gear tooth please

OK THIS IS WHAT I WILL DO SATURDAY first i will remove my manifolds to get to the plugs, more easy, to get at the plug holes, i have a remote start so i will hook that to the starter, so i dont need a second person to crank the engine for me. i will take out all plugs, do a compression test on all 8 cilinder, dry. put all the result on each cilinder on a piece of paper. then i will pour a little oil in each cilinder and see if my reading go up or down,. so if the readind goes up on a low cilinder reading after i put the oil, that means i need piston ring on that cilinder, right or wrong???? but if it does not go up the problem is in the head valve seal ect right or wrong??? corect me everyone if i am wrong so far, because by the hook or the crook that engine has to perform next season.

Don S · Dec 1, 2005

Re: info on outdrive gear tooth please

Just so you know the prefered method, here is a Merc service bulletin on the compression test. http://www.boatfix.com/merc/Bullet/97/97_25.pdf From the sounds of things, it sounds more like a timing problem than anything. Have you checked the timing, and advance timing? Has a real tuneup been done? Cap, rotor, plugs (Not Champion) fuel filters replaced, vacuum gauge test with engine running? Here is a list of possible things that can cause low rpm. Start checking them off as you KNOW they have been checked.

bolo789 · Dec 1, 2005

Re: info on outdrive gear tooth please

thanks don, make a lot of sense as usual. one last thing, when i was tunning the carb, one of the two screws has no ifect when turn in all the way, it does nothing. but the other when turn in all the way it want to shut the engine off, and when the engine was idiling, i always see gas dripping in the carb, from searching the site i learn thats a no no, so now iam hoping all this problem is a bad carb, thanks again don and the guys, i will post when i do the compresion test saturday.

Don S · Dec 1, 2005

Re: info on outdrive gear tooth please

You have carb problems too. Rebuilding is possible, but then again it may be wore out. I can't see it or inspect it, so who knows.

bolo789 · Dec 1, 2005

Re: info on outdrive gear tooth please

thanks don, make a lot of sense as usual. one last thing, when i was tunning the carb, one of the two screws has no ifect when turn in all the way, it does nothing. but the other when turn in all the way it want to shut the engine off, and when the engine was idiling, i always see gas dripping in the carb, from searching the site i learn thats a no no, so now iam hoping all this problem is a bad carb, thanks again don and the guys, i will post when i do the compresion test saturday.

bolo789 · Dec 1, 2005

Re: info on outdrive gear tooth please

don at idle the timing was dead on at 8 deg no wandering of the marker either. but i did not check the advanc of the distributor.

whywhyzed · Dec 1, 2005

Re: info on outdrive gear tooth please

I would go for >500% accuracy on the firing order.... septuple check that.. while youre putting on the new ignition wires

bolo789 · Dec 2, 2005

Re: info on outdrive gear tooth please

ok so without the correct firing order wouldnt the engine miss fire>>?????? just want to be sure, because the engine runs smooth as ever it idle 7500 rpm with no miss. but i will take a look at the firing order. thanks

Don S · Dec 2, 2005

Re: info on outdrive gear tooth please

If they were out of order, it would run rough at all speeds.

Weirdwalt · Dec 2, 2005

Re: info on outdrive gear tooth please

Since you are taking off the manifolds, you should check the flappers, they can cause a power loss.

info on outdrive gear tooth please

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