A first, Mariner built in cylinder head?

[gazza2006au]

While i was on my short journey looking for a 21+ footer to convert to CC i came a cross a you beaut little 15 footer glass boat runabout, now i use to say i would never touch a second hand fibreglass boat unless i replaced the floor,stringers and transom but thislittle boat really appealed once i seen it in person its a SilverLine 15 footer ok its not the 22-24ft boat i was looking for but i was impressed with it and the amount i paid is next to nothing

it has a 50hp Mariner 3 cylinder around the 90's era the seller said the top cylinder had problems i seen they replaced 2 of 3spark plugs or the top spark plug ran extremely hot and burn the plug, i opened the exhaust port to see the top cylinder piston melted

i have come across melted pistons before due to my self trying to clean out a carby on the water i was young and dumb... but this one has 2 carbies for 3 cylinders so why didn't the second middle cylinder melt also?

have one more question how do i get it resleeved if the cylinder head is combined with the block?

[up the creek]

awesome bro i just want to share your joy of this boat, i cant help with the engine mechanic stuff, but thats what its all about for me, it was older not as long but you love it, as said my dad back in the 90s had like a 70s 15 foot stejcraft we put a v4 115 evinrude old motor on back it was a wicked little boat that gave us years of fun... funny enough i wanted new new new, but cant afford it and lately have been lookin for a around 15foot older glass boat and with a 90- 115hp donk,, i hope u get it out there and have some fun..

[Steeler]

While i was on my short journey looking for a 21+ footer to convert to CC i came a cross a you beaut little 15 footer glass boat runabout, now i use to say i would never touch a second hand fibreglass boat unless i replaced the floor,stringers and transom but thislittle boat really appealed once i seen it in person its a SilverLine 15 footer ok its not the 22-24ft boat i was looking for but i was impressed with it and the amount i paid is next to nothing

it has a 50hp Mariner 3 cylinder around the 90's era the seller said the top cylinder had problems i seen they replaced 2 of 3spark plugs or the top spark plug ran extremely hot and burn the plug, i opened the exhaust port to see the top cylinder piston melted

i have come across melted pistons before due to my self trying to clean out a carby on the water i was young and dumb... but this one has 2 carbies for 3 cylinders so why didn't the second middle cylinder melt also?

have one more question how do i get it resleeved if the cylinder head is combined with the block?

I would be very surprised if it is bad enough to require re-sleeving ?. We once stripped a siezed ( from overheating then ants nests ) inline 4 blue band. Had been stuck neglected for about ten years. We soaked cylinders with inox for a couple of days ( plugs in ) then suspended it upside down by the crank ends with a mattress underneath . One and a half days later here is a block minus the crank and pistons landed on the mattress. A bit of work with the stones in a drill attachment and all 4 cylinders came up a treat. Those Merc linings really are bullet proof and do take quite a bit of punishment. Honestly old mate and i have probably freshened up two dozen old Merc/Mariners ( 3, 4 and 6 Cyl's ) in the last 10 years and never had to junk a powerhead, the odd crankshaft or two but never a powerhead from stuffed linings. As for your melting and being the top cylinder perhaps a long term ignored ignition issue, but truly that is only i guess. Stators and switch boxes and solenoids for that matter were not exactly a strength of Merc LOL. Is the model the last of the 3 piece wrap around metal cowel types with separate top and front.

[gazza2006au]

Steeler yeah mate shes the old wrap around cowling but in bloody good nick besides the cylinder, she has genuine 127 hours on the clock and the boat and motor were married from the beginning, tried to take some pictures because u cannot see into the bore in daylight the top faulty cylinder looks pretty nasty, if i hone the cylinder would that imbed more of the pistons alloy into the sleeve?

hard to see the scoring because the pistons have a crown which is in the way

[Steeler]

Never had an issue of imbedding any alloy into the lining during the honing process. Looks a treat decals and original finish still look very nice.

[stevej]

the hours run are irrelevant
the hours sitting not being used matter more

died from neglect and lack of use

[ericcs]

[QUOTE=gazza2006au;
it has a 50hp Mariner 3 cylinder around the 90's era the seller said the top cylinder had problems i seen they replaced 2 of 3spark plugs or the top spark plug ran extremely hot and burn the plug, i opened the exhaust port to see the top cylinder piston melted

i have come across melted pistons before due to my self trying to clean out a carby on the water i was young and dumb... but this one has 2 carbies for 3 cylinders so why didn't the second middle cylinder melt also?

have one more question how do i get it resleeved if the cylinder head is combined with the block?[/QUOTE]

maybe the middle piston survived because it probably is partially fed from the bottom carbie. So maybe it has a lean running top carbie after all?
All the merc's without removable heads have the pistons inserted via the crankcase, so any honing or re sleeving is done that way also!

[up the creek]

the hours run are irrelevant
the hours sitting not being used matter more

died from neglect and lack of use

my 1st motor was a 1971 redband 20hp i bought it for $400 from a outboard wrecker, in 1995 so it was 24yo and it was still running and starting 1st pull wheni got rid of it, maybe electrics and rubber hoses die in time but outboards are mostly metal and if stroed in the right humidity and out of the weather etc can last 30 years or more in rare cases,

[gazza2006au]

I just picked up a Android Endoscope from Mitre 10 for $2 on special on ebay tried to get some pictures of the bore but i think the focus on the ES camera is poor up close i do have some pictures tho can show

i see parts for this motor cost a bit in Au but are pretty cheap in the US like the crankshaft i think might be rat s... because of how badly all 3 cylinders are scored especially the top cylinder

might look around for another powerhead or consider rebuilding this one either way i think shes a keeper, the boat looks to have been in storage or owned by an elderly person and kept in really good nick for a decade

scored the whole package for 1k boat and trailer registered too my mate reckons its worth 6-7K

[up the creek]

if your willing to spend more money on it gazza, as you think it is worth it,,, at the least its a good project if your havin fun playin with it..

[gazza2006au]

Just got on the laptop and uploaded those images from today's endoscope footage and the bores are terrible check it out this should all be nice X hatch scratches for anyone that doesn't know about engines

[ericcs]

split the case and run a hone through each bore, may not be too bad. nothing to lose, won't cost anything if you have the equipment!

[Steeler]

That mark in the bottom pic looks average and looks to have a bit of depth to it but as ericcs suggested run your hone through it and see how it comes up

[stevej]

I had a few red bands and brown bands you could stick screwdrivers through them due to corrosion
its all a bit of luck as well

more the point 1000 hours fully maintained can be better then 20 hours sitting for 10 years

[gazza2006au]

I picked up a short block for under $400 delivered, this one will go out in the shed i will pull it apart later on, atm i'm getting a 25 yamaha ready for sale need to build the block back up so that has my devoted time at the moment

i will update this thread when i get around to stripping the blown engine and let u know if those scratches clean up, the motor has not one spec of salt internally, not one spec of corrosion either however the exhaust port looks well used so the motor has been ran i just don't know if its recent or donkeys ago