How do these old 50hp yamaha 4 bangers go

[gazza2006au]

Might be prudent to check the lower end too, just in case it's been submerged and only just had some new oil put in it, is there any way to inspect the internals on that model without pulling it to bits?

Noel nah it hasnt been submerged there is no rust or salt build up other than on the valves and the cylinders, the engine still turns by hand if it had been sunk it would have seized up

4 strokes run mostly aluminium shell bearings in the bottom end which is a bonus as they dont rust from what i have seen

I just need to get it started asap andget it all freshly lubed

[gazza2006au]

Gunna i'll let u in on this one deal

https://www.gumtree.com.au/s-ad/bero...air-or-parts/1

https://www.ebay.com/itm/Mercury-75h...temCondition=4

I think thats an ok powerhead i didnt read the description, for this mercury 90hp its best to buy it strip it, look up the parts on USA and Canada ebays ask sellers if they ship to australia most will say yes make sure u tell them you'll pay any shipping cost,

For that 90hp mercury its better to buy anew powerhead in pieces asthey sting u good money for a complete powerhead where as individual parts are cheap as

When u search ebay search "ebay.com" (usa), ebay.ca (canada) wordsto type in are "mercury" "90" "90hp" "75hp" "efi" and various year ranges..

Also look for interchangable models yamaha, mariner etc.. it'll be the same item just different colour

Stay away from DFI 2 Strokes as powerheads cost a fortune in the usa

[gazza2006au]

Seen a aluminium welder he quoted $300 to weld he viewed the job, i just called a machine shop they want $120 to resurface the head

$420 to repair it, awrecke rsjust quoted me on asecond hand head from QLD $750+ postage + resurfacing another $120

So it looks like my head is getting repaired

[gazza2006au]

This is becoming quiet costly, cylinder head was marvously tig welded for $300, head is in a shop getting resurfaced and valve seats snd faces recut another $250

Than i need the main cam seal, 8 valve stem seals, and a head gasket

Probably about $700 to repair the head and bolt it on fmj

Engine is going to my cousin for what its cost me, he has his eye on a 17ft basic pressed tinny but he hasnt bought it yet fingers crossed he gets it

[gazza2006au]

This is blowing out of preportion im in it clost to 1k in repairs fmd got my head back from the machine guy he threw 70 on top of the original bill for the sake of it, maybe i should get quotes in writing

https://ibb.co/tw6BPqV

https://ibb.co/x1tJPpM

https://ibb.co/4T5R7y9

[catshark]

its costly no doubt, but its a specialist service, does recondition head come with any warranty

[gazza2006au]

Hey Cat he offered afull head recondition service minus welding for $450, i was quoted $250 to resurface and cut the valves and valve seats than he springs $320.. im not happy with that kind of bull shit

Welding cost $300, gaskets and seals are costing another $250

Im in it $870 + oil + the purchase + fuel picking it up

[gazza2006au]

I wasnt ganna post this.. but using two different shops hasnt paid off with the repairs

I have to go back to see the welder but im unsure of what i will be told, after the head was resurfaced the welds have lots of pin holes in the surface

Im not sure if it were defects in old mates welds which looked really nice or if the machinist who charged me $70 extra has used a punch to #### up the job or if this is just how it came out

Do i just cop it on the chin and fork out roughly another $400 to have it repaired a second time?

I have never been in this situation before, when u pay a ton of money u expect a job to be done at lease to a standard

https://ibb.co/3Cn302X

https://ibb.co/8B3hkCM

https://ibb.co/ZHcYB3N

https://ibb.co/9nNqSGV

https://ibb.co/8PzNcj5

[shakey55]

I know absolutely jack about metals an welding. Gazza from what i see, nobody had purposely attacked it with a punch.

Before jumping to conclusions, ring the bloke and have a civil conversation about what you see and your thoughts. He may have an answer about the finish, offer to send him the pictures so he can see them.

As I said, I know nothing about metals or welding. Good luck and I hope it all works out


Sent from my iPad using Ausfish forums

[gazza2006au]

Hey Shakey the pin holes all seem to be round there are around 30 pin holes it just seems strange that they are all perfectly round and fresh clean shiny aluminium

I will go back to see the welder and get his opinion but unfortunatly im not going back to the same machine shop i just cant afford to pay the bill plus whatever he puts on the top

Will let ya's know in the next few days what the go is

The welder done a bloody ripper job welding such a head his tig welds were so smooth and tight i really cant see it being his welding but will see

[shortthenlong]

Looks like weld porosity issue to me.

Matt

[catshark]

sometimes they pin the valve seats in the head with a centre punch , but it just looks like weld issue near the water gallerys , i cant see coolant escaping via the pin holes , id continue on with the head gasket , bolt her up

[CT]

You need to have this handled entirely by one shop.

Agree that it's porosity but if its not going to lead to cracks, how far are you going to chase it?

[gazza2006au]

Just got caught in a pinch and had to way over spend i placed aorder yesterday with abig yamaha au dealer and was told the head gasket will be a 12 week wait and orders are taking a full 12 weeks to arrive

I just had to order one out of the USA where shipping cost a whopping USD$63!!!

Good thing the order should be here next week, but coming from USA via express what precautions should i take? Bomb it with glen20?

[gazza2006au]

How unreal is that order placed friday order sent out within 3 hours!!! Estimated delivery Wednesday, Friday to Wednesday USA to Australia fm and Australian post and couriers take a whole week shipping with in the country