Powerhead removal 90hp yam

[dreemon]

Hello all,

Been tring hard to get my PH off but doesn't want to budge, I've found there are 8 long bolts and even though I took heaps of time trying not to break them 3 of them broke from me, 2 were broken off b4 I got to it so 5 out of 8 plus there are 3 shorter bolts (1 in rear and 2 front) easily removed.

I have the engine supported with a rachet strap and with alot of tension to help release the motor from the exhaust plate, seems corrosion is my enemy due to the prev owner in a few ways,

reason for removal is water and exhaust spitting out from under the cowling skirt at the front where the steering bar enters the engine, and want to fix it before it gets out of hand ,

I figured the bolts would be bad but the head wouln't seperate so I drilled through the squash/ sandwich/exhaust plate side and through the 5 bad bolts, drilling through the plate was a last resort,


still stuck ..... any other Ideas to try guys ?

I'm leaving the engine holding up the boat and trailer overnight with spray and a putty blade jammed into the gasket joint.

[FNQCairns]

There is also 2 shorter bolts inside rear under the cowl? i had mine in bits a couple of years ago, to separate the powerhead i used a block and tackle to suspend the entire engine and although i tried everything gentlle first, only getting rough with it worked via a wooden lever and wooden drift and hammer.

Good luck hope the rest runs smooth also but I kind of doubt it.

cheers fnq

[dreemon]

Thanks FNQ, Been using some hardwood and will be going to use the ironbark hardwood next with a bigger hammer in the morn, had anouther look for the 2 short bolts at the rear but I didn't see any more holding it appart from the bolts from plate to trunk, and that will have to come off now to replace

I also doubt the rest of this mission will go without a few more broken drill bits and betting this will see two boxes O beer before it's put back together ,

I can tell it's louder than before but I wonder if it affects any performance as alot of fuel seems to spit out of the area leaving a milky oily film down the leg and the prop is clean ?

[dreemon]

Would removing the gearbox help in getting the powerhead off?

[FNQCairns]

Probably not a help in breaking the seal but the leg is best gone anyway. If the whole engine is hung by the lifting loop on the powerhead it's easier to shake the shit out of the whole engine with leg removed.

Actually you have reminded me I need to crack and re-grease each of those long bolts again.

Sorry it's been a long time since I did mine and it was the first yamaha I had tinkered with so I cannot remember many specifics now, perhaps a manual might help they are pretty crappy but sometimes a person gets lucky chasing specific info like how many bolts need removing.

But seriously it was VERY hard to get the block seperated I too also jumped on the net looking for any advice just incase i missed a bolt somewhere unseen, only after this did I get real rough.


cheers fnq

[dreemon]

It Might not help me with the box off then, I have mine supported with an ext ladder that is counter levered from my ladder rack on the back of my ute and a timber stud with a jack under it to hold the weight of the engine along with the rear of the boat ( off the trailer rollers by an inch ) still bolted to boat.

would like to be able to shake shite out of it but the good news is " I think" it has seperated about a 27th of a mil ;D using scraper blades to smash into the gasket, I'll see if I can get the bottom cowl off to get around the whole engine

[FNQCairns]

Again good luck but be very careful with the non replaceable mating surfaces!!!!!, when you do get the powerhead off there will be a fair bit of work cleaning and fitting replacement parts to get the midsection section and engine mount/water tube/ adapter plate areas back to long term serviceable.

If you can wait 7 days for parts try boats.net for most of the replacement bits, I rebuilt almost the entire midsection with parts from here at a cost comparable to wrecker prices by the time they hit my door...there is no substitute for new parts.

Once this area is back up to scratch all other parts of engine apart from the pivot tube (consider dealing with his also while you are there) also the PTT to a lesser degree is a relatively simple affair to plan and fix on an aging o/b.

cheers fnq

[dreemon]

The engine is OFF ;D, and in 5 main parts, only the mount bracket with the PTT is left on the boat, and your right about the other bits needing to get replaced, mount bushes, shaft seals, plate, and other bits, the pivot tube is still really good with hardly any play, now just need to remove the broken bolts and start ordering the parts, clean all the areas , repaint and assemble it close to what it used to look like,

I don't think I can wait the 7 days like you for parts, only because i don't want to forget the order to put it back together,

turned out the gasket area around the exhaust was blown out


Thanks again FNQ 8-)

[FNQCairns]

Good news dreemon, I wasn't much if any help it's just good you can now move on, nothing worse than a boat that is just a float!:)

cheers fnq

[dreemon]

FNQ, What do you mean ? your the only one that helped and I really appreciate that, the hit it harder helped heaps;D and all the heads up.

it's an interesting/eye opener area of the outboard, how cool is it to see the engine break free ! also strange to see the powerhead on my bench, and heaps of outbard in the driveway, the wife will be rapt in the morn when she comes back from her hoidays::)

did you replace your shift rod at the same time on yours?

I'll buy as much new parts as i can afford and put them where ther're hard to get to, but for sure will make it a long term fix,

I guess every 3 years would be good to grease those long bolts, I ended up angle grinding the 5 stuck bolts through the plate to cut them off again

Thanks again N Cheers !

[Noelm]

this is way off topic here, but it applies to the same motor and just may help someone some day, my mate in Caloundra has the same motor and was out the other day and the motor just stopped dead with a rather sad metalic sound, fearing the very worst, he called his mate and got a tow back, on the trailer and home again, a quick cup of coffee before he was game enough to look at the motor, he worked on it for ages, looking for the bad news, and it turns out the flywheel is made in two bits, an inner bit that fits on the crank, and the outer that holds the ring gear and stuff, somehow it has shifted, and was sort of slipping on the centre, this of course puts the timing way out and makes a terrible noise, he called a local wreckers and got a second hand one, the wrecker said it happens all the time, never seen it myself, or heard of it before yesterday, but a simple fix for what seemed like disaster, so might just be something to look out for.

[FNQCairns]

Thanks Noelm that's worth noting for the future, probably a bloody rubber bushing/separator...they never work well for a long time on anything.

Dreemon I did replace the shift shaft when I did mine then I painted again over the top, guess it depends on how bad yours is, mine was well rusted as was the pivot tube and steering neck.

My mounting bolts all came out without too much trouble luckily, I was sweating on them for a week until i couldn't delay any longer, sometimes one gets lucky, looking to keep it that way.

cheers fnq

[dreemon]

The shift rod does'nt look that bad after I cleaned it up, will give it a good etch prime and paint too, my engine mounts on the top were expired. $100 ea:( but came off well, will be getting new gaskets and drive shaft seals next week, the plate new is just under $500, but found one for $100,

My wife got back this morn, saw bit's of motor scattered and said " how are you gonna get all that back together?" "B.O A.T " I said

if your going to re-grease your long bolts on yours, I think you'll find it hard to get them right out, seems the bolts will start to drag on the trunk unless you pull the plate off, so expect to only grease the bottom half which is still ok cause at the bolt head is where the corrosion hits and where it snaps,

I'm tapping grease nipples into every place theres a bolt on my engine now::).

Noelm, not looking foward to that day , suppose it'll only happen sometime after leaving the ramp , at least it's repairable?

[FNQCairns]

B.O.A.T, LOL. Yeah it gets like that.

Thanks will have to see how those bolts go when I get to them, I cannot remember them doing that, bit of a pain.

Be sure to run a good straight edge over that secondhand plate or you could be sorry.

You will be impressed with new upper mounts.

Don't forget that little plastic washer at the top of the water tube for a compressed fit, mine anyway was totally stuffed.

cheers fnq

[dreemon]

Picked up the plate this morn and good with only a qwerk from a prybar but I'll get around it with J.B. weld, great 2 part stuff and not affected by heat, also found that the main culprit was the drive shaft seals leaking !! ! !

it wasn't actually all exhaust smoke, we could see milky oil running from under the cowl and smell of fuel,

you gave me some fuel figures before and they havent matched up, I think you said the best I could get was 2.2 klm per L , my last trip i got 37 k's out of 23-24 Litres, I think after all the repairs are done your numbers will be spot on ;D,

heaps of cleanup left to do, but I like beer better, Cheers !

[FNQCairns]

Yeah that's the economy I was getting with 17p and a light 6m boat, cannot push 17p any more so i get less. Your economy ATM is really bad!! worse even than my boat now with 15p and running heavy.

It's good your getting it all sorted, hint - pool acid works like magic cleaning up scale etc..of coarse all of the typical safety yada yada applies.

cheers fnq

[dreemon]

FNQ , It's all back together, repainted, went together well and used "perfect seal" on the gasket surfaces, and all the good types of grease on bolts and rubbers.

took it for a good run today and it's running great and fuel economy is better now, last time it was only me and my 8 yr old boy and this time with wife and both kidds and 22 L took me 41 klm so it must have been spewing around 3 L of petrol before :-/, should get even better once I stop using the WOT option, Cheers

[FNQCairns]

FNQ , It's all back together, repainted, went together well and used "perfect seal" on the gasket surfaces, and all the good types of grease on bolts and rubbers.

took it for a good run today and it's running great and fuel economy is better now, last time it was only me and my 8 yr old boy and this time with wife and both kidds and 22 L took me 41 klm so it must have been spewing around 3 L of petrol before :-/, should get even better once I stop using the WOT option, Cheers

WOT! will get you every time!!LOL

Sounds good, you sure got stuck into it.

Time now to forget about all this stuff and just go enjoy.

How do you rate the new rig over the old one??

cheers fnq