great top end but bad crank seals/ how much $$$ ?

[1800chall_tim]

my twin 787's have great compression in all cylinders (151 to 152 lbs.) , and i do think there is very little hours on entire boat. the problem lies in the port engine, the crank seals are bad and i was wondering if it would be worth the savings to just do a lower end rebuild.i think i can do all labor my self and am looking to do it for less than $1000.i think i saw a post that said there is a place to send my crankshaft to have it split and put new seals on it. other wise what else would i have to purchase besides new crank, crank end seals, rotary valve seals?, gasket kit, loctite 518. thanks any advise would be greatly appreciated. Tim

 

[Dr Honda]

Yes... you have to do a full disassembley of the engine to get the crank out. Then... to replace all the seals... you have to press the crank apart, and replace them.

It's not easy to do., and generally, you will just replace the crank with a rebuilt.

So... why do you think your seals are bad? What's it doing??

 

[1800chall_tim]

the symptoms are this, when it sits for more than a week the forward cylinder fills with oil. i have to pump it out the plug hole or else the engine hydro-locks and wont turn over. it is a 1999, so being 13 years old i guess most would rebuild top and bottom while it is apart. i priced it through SBT and to get a new crank is $275. would you touch the top end other than a good cleaning and new gaskets?

 

[1800chall_tim]

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i purchased this boat last year in august, and yes, i did test drive it. ran great, lots of response,no cavitation, clean mint condition interior, great condition outside (graphics, gel coat, hull, trailer)everything looked sweet. so of course i paid fair market value of $7500. only to find out two weeks later the rat bastard i bought it from pulled a fast one on me. he must have pumped out the oil ahead of time and "put the fake on it". now i have to put several hundreds into it just to get it back to were it is worth 7000.

 

[Seadoobuddy]

If you are going to all the trouble of tearing it down then do the top end also or at least rings.

But, a TEMPORARY fix is to pinch the oil line during NON-USE time. you must unpinch it when riding it of course.

 

[Robj]

If you are going to all the trouble of tearing it down then do the top end also or at least rings.

But, a TEMPORARY fix is to pinch the oil line during NON-USE time. you must unpinch it when riding it of course.

That is what I would do, and fix it in the off season.

 

[Dr Honda]

Yep... pinching the line is a good band-aid for your problem.

SDB does have a point. If it's the factory engine... I don't think I would just try to fix the crank. If the plan is to keep the boat for a few years... I would just do a full rebuild, and make it reliable for the next 10 years. If you just swap the crank... you could have a piston give out in the near future.

 

[1800chall_tim]

If you are going to all the trouble of tearing it down then do the top end also or at least rings.

But, a TEMPORARY fix is to pinch the oil line during NON-USE time. you must unpinch it when riding it of course.

how long should i dare go without a rebuild? if i keep on just pinching the lines what will happen in the long run? i haven't yet found a post on here that says what the end result is from ignoring bad crank seals. 5-10 minutes of prep at home before a day on the water isn't that bad right now. i imagine the starter in the port engine will be the first to go due to all the extra cranking to rid oil from cylinder.