Yamaha 15F 2-stroke. Purchase, check & Service. - Page 3

Highland Haggis · 06 August 2019, 19:28

Fenlander I think your reviews are spot on and very helpful look forward to hearing the next trial's that you do HH

jeffstevens763@g · 06 August 2019, 20:22

I think this points out to all that propping isn't an exact science so many variables and what works in one scenario doesn't in an other. I do agree that loco seems to play the same record whatever information is given for a current set up ignoring previous information supplied by the OP not good for those who are trying to learn from expearianced boaters to maximise performance for their set up and restraint in that respect would be welcome IMO

Locozodiac · 06 August 2019, 20:35

Fenlander, If the post is quite long definitely not. Oh come on, I'm just sharing my own boating experience with motor tachs with other boaters. I'm beginning to think that you and jeffstevens have some sort of issues with me and my posts ?

Happy Boating

jeffstevens763@g · 06 August 2019, 21:05

Loco the only issue I have is that you seem to say the same thing over and over you will know if an expearianced boater that nothing is as the text book and individual findings are welcome, so many variables with any boat there is no fixed rule. Fenlander is very renoune giving a very full account of his expeariances of his set up and previous findings. We should welcome this and learn.

Bigplumbs · 09 August 2019, 06:07

Loco

You waded in telling people how to do things when Fenlander was doing an excellent Job in his description of things. All you have done is potentially confused people who otherwise might have benefitted from this thread.

I also wonder if you read just the last post or the whole thread

Happy Boating

Fenlander · 14 August 2019, 15:11

Anyway back on track... few non-urgent jobs I had in mind just completed.

One of the clamp handles (plastic) was broken at the end so I drilled out the old pin and replaced it with a new OE Yamaha handle and supplied pin. The pin comes drilled hollow one end so once in place it can be belled out. I found the ideal former to do this was the end cut from a modern woodscrew using a large G-clamp to force it in.

Fenlander · 14 August 2019, 15:15

The main anode above the prop looked pretty ratty... probably still working but while I was doing these small jobs it went on the list. I'd had the bolt out at the initial service so knew it wasn't at risk of snapping which is a consideration with any bolt in the lower leg area on a 16yr old outboard.

Fenlander · 14 August 2019, 15:20

Finally for now I replaced the tilt rod. The original one is the plastic ended version. I've cleaned it up to keep as a spare but it had lost its plating and rusted instantly at a sniff of salt water. It is a neat design as it can be easily inserted one-handed but Yamaha have found the plastic retainer can age and snap allowing the rod to fall off the outboard. So they have replaced it with a more standard design loop ended drop nose rod but keeping the same part number.

spartacus · 14 August 2019, 18:48

Nice work Fenlander.

Bet you paid a pretty penny for genuine Yamaha spares, but hey it's worth it as engine looks mint. The anode looks like it would have lasted a few more seasons, but good to call to replace.

Fenlander · 14 August 2019, 19:23

Just looking through the invoices the Yamaha service parts etc were about 25% up on decent quality aftermarket (don't count direct from China no-brands). The biggest uplift was on Yamaha props which are 100% up on the aftermarket ones I tried but the casting/machining quality and consistency of performance was worth it.

Regarding the work and spend overall my thought was at 16yrs old... and as usual with outboards of this age no certain history... once I was happy it was worth keeping then a complete mid life overhaul was in order.

At the season end the head and exhaust/water jacket cover are coming off to ensure the waterways are clear plus an overhaul to the carb and fuel pump plus check the reeds. Then with routine yearly work it should be good for another 16yrs.

Must mention MarineTech on the Norfolk Broads who've supplied the parts and props via their Ebay store. Seven orders so far and every one spot on with correct parts and quick delivery.

https://www.ebay.co.uk/str/marinetechboatsandoutboards

Bigplumbs · 15 August 2019, 05:17

If you are not careful this outboard will be like Triggers broom

Fenlander · 15 August 2019, 10:04

Ha ha yes... I think I'm rewarding it for the success of its power vs weight getting us back to where we want to be after the previous three years of a too heavy/bulky 20hp then too low power 9.9hp.

Fenlander · 29 October 2019, 11:56

2019 has been difficult to find time to get to the coast so decided to call it a day for this year and see what next season holds. When I bought this Yamaha in June and gave it a service it was always a plan to do a couple more things towards a mid life overhaul before it went away for the winter.

I wanted to have the head and exhaust plates off to check for any lodged salt deposits, check the bores and the internal anode. Also to remove and strip the carb/fuel pump.

Thankfully due to their high grade all the head bolts came out OK. The head was well stuck though but with two bolts left in loose a few clouts with the hide hammer freed it. The lower bolts for the exhaust plates were quite difficult to access and there was only just enough clearance to get this plate off without removing the powerhead.

The head gasket was firmly stuck to the head but came off with a plastic scraper.

Fenlander · 29 October 2019, 12:02

Deposits in the waterways were minimal but there were a few small "salt jelly" bits starting to build in the odd place as indicated with the pencil. I soaked the head and exhaust plates in a warm water soda crystals solution which cleaned them up nicely and helped soften the gasket remnants for easier removal. The small amount of deposits in the waterways were removed with a mini hacksaw blade and carb cleaner spray.

In the last image you can see the internal anode bottom left of the upper cylinder. It was fine to leave in but for something that may be regarded as a maintenance item a right faff to need the head removing to access.

Good to see no scoring on the piston skirts and no cylinder wear lip.

Fenlander · 29 October 2019, 12:15

The carb of course is really easy to remove with just two bolts, three throttle/choke links and the fuel hose to undo.

The float bowl was amazingly clean (in the image just drained not wiped out) and jets clear. The float height was right at the limit of the acceptable range due to wear on the needle rubber tip meaning the fuel level would be a few mm higher than ideal. You get a new needle and float in the carb kit anyway.

You can see in the bottom left of the third image the fuel pump diaphragm is stretched so that will be replaced.

The reeds were perfect both in closing properly and the stops allowing full opening. About the only difference between the 15hp and 9.9hp is the 9.9 having a reed set with tighter stops greatly reducing opening. No reason at all why mine should ever have been fitted with the wrong reed set but it was a check I'd wanted to make.

On this occasion I'd decided not to order the gaskets etc until I knew what I needed so it'll be a few days before I put it all back and bucket test before winter storage.

Bigplumbs · 29 October 2019, 21:28

Fenlander

What is your opinion to the old adage...….. If it aint broke don't fix it !

jeffstevens763@g · 29 October 2019, 22:09

It's a well looked after engine better keeping it that way IMO it'll see you out David great info

Fenlander · 29 October 2019, 22:10

Cheers Jeff.

BP it's a personal thing and I'd not argue strongly what others should do it's just what suits me.

Bear in mind I was fiddling with vintage motorbikes in my teens then worked in engineering for 20+ years then I ran an in-demand small motor engineers for about the next 20yrs. So these jobs I do are really second nature.

The way I've been trained and the way that gives me the best results/satisfaction is a high degree of preventative maintenance.

So when I buy any used item... particularly at 10+ years old... I go through every aspect in the first few months of ownership so I have total confidence in it.

Taking the most recent posts above had I found the internal anode eaten away I would have saved excess future corrosion by replacing it, had the waterways been more blocked I could have saved a potential overheat breakdown, had I seen scoring on pistons or bores I might have decided it had been run with insufficient lubrication in the past and wasn't a keeper, had the carb bowl been full of silt in the corners it could save a breakdown getting it all clean.

The fact that all these things were OK doesn't make me think I've wasted effort/money. The opposite actually in knowing exactly what's what internally.

And the one thing I did find... the nearly out of spec float height due to worn pin tip... could have led to over-rich running so best dealt with.

I think that probably answers the question... without answering the specific question.

phantom 19 · 29 October 2019, 23:35

Someone from Mercury had infiltrated Yamaha when they designed the 15F - Yamaha designers of of old would never have that many linkages and plastic on the engine.

The 15F was never as durable as the older 15D. Crank labyrinth seals would fail on them whereas the D would still be soldiering on today as long as it’s driveshaft hadn’t seized into the driveshaft housing.

Bigplumbs · 30 October 2019, 07:19

Quote:

Originally Posted by Fenlander

Cheers Jeff.

BP it's a personal thing and I'd not argue strongly what others should do it's just what suits me.

Bear in mind I was fiddling with vintage motorbikes in my teens then worked in engineering for 20+ years then I ran an in-demand small motor engineers for about the next 20yrs. So these jobs I do are really second nature.

The way I've been trained and the way that gives me the best results/satisfaction is a high degree of preventative maintenance.

So when I buy any used item... particularly at 10+ years old... I go through every aspect in the first few months of ownership so I have total confidence in it.

Taking the most recent posts above had I found the internal anode eaten away I would have saved excess future corrosion by replacing it, had the waterways been more blocked I could have saved a potential overheat breakdown, had I seen scoring on pistons or bores I might have decided it had been run with insufficient lubrication in the past and wasn't a keeper, had the carb bowl been full of silt in the corners it could save a breakdown getting it all clean.

The fact that all these things were OK doesn't make me think I've wasted effort/money. The opposite actually in knowing exactly what's what internally.

And the one thing I did find... the nearly out of spec float height due to worn pin tip... could have led to over-rich running so best dealt with.

I think that probably answers the question... without answering the specific question.

each to their own of course. But my old Dad used to say when we went out for our Sunday drive years ago that the cars broken down on the side of the road were the ones where the owners had fiddled with them earlier in the week.

I am on the other side of the argument to you but as I said each to their own.

Regards

Dennis