Yamaha 40V refurb/restoration

[Livid]

Been a busy bee the past few weeks. Got my Yamaha exhaust tuner cut and welded to a similar style of the hydrotec marine one. Difference is the hydrotec is about £500 to get in the UK and I spent £160 on mine

To fit these funnel tuners you need to cut about a foot off the silencer, interested to see how much more antisocial it's going to bed. It was already quite smoky and noisy. I'll never have the most antisocial boat in the family because my uncles have a Mariah and a faery which both sounds like Shrek gargling bricks and broken glass.
I gave the exposed metal a quick coat of zinc based primer to stop it corroding, i don't want my shiny new exhaust manifold falling off

After the paint had dried it's finally time to stop taking it apart and start putting it back together. Helicoiled a broken stud hole in the top brakcet. Replaced all engine mounts whilst it was all torn apart too, don't want the engine falling off.

I had to get the lower unit off the leg to get the whole thing back together and my idiot brain forgot to remove a bolt and I ended up chipping the brand new paint which I'm never going to forgive myself for 😂😂 but it's reasonably hard to see so it should be fine.
Finally got the whole assembly back on the engine bracket. This is the first big bit of progress on getting this back together.

I gave up on getting my carbs bored out and sniped some Yamaha pro50 ones on eBay that'll do a fine job. My original carb bodies are lost in the post still and I gave up waiting. Still waiting on parts to get the block back together but I'm going to be able to service and install the lower unit and strip and clean the new carbs

[ollyit]

love your work mate

[Spreu-boote]

Wow nice update! Cant wait ro see it in the water

[Livid]

Been another few weeks and a lot more work. This is starting to get very close to being finished.
Got the leg on the bracket. Serviced the impeller whilst I was at it, no better time to do it. Only service thing left is the gear oil which I'll leave until I have slightly better access to the bottom because there's so many other engine bits around the garage I can't really get to it.

Stripped back my eBay carbs to check their condition, they were alright but quite worn, I'll need to get a proper rebuild kit into them before I properly run it. Was missing an o ring too.

My last parts order finally arrived so I was able to get the pistons on the crank. I decided in my infinite wisdom to not buy the correct tool for the job and had to hunt around the house for a bit of pipe the right size to hold the needles in place as I slid in the pin. Ended up using a bit from a old torch which did the trick. The little clips that hold the pins in were fun to deal with, one went flying into my hair at one point

Then I dropped the crank into the cylinder body. Hopefully it's the last time I see it but knowing my luck this time next week I'll be ripping it all apart because it exploded. Got all the bolts torqued down and sealed up.

Still to do is a lot of small things. I need to fit the oil seals onto the block as well as drill out a few broken bolts, get the flywheel on etc. I'll probably attach most of the accoutrements whilst the block Is off the leg, will make things a bit easier. I need to purge the oil system with fresh fully synthetic because what's in there now is not trustworthy at all. I also need to clean the gasket surface on the bottom of the block because I didn't do it earlier for some reason best known to the octopus that lives in my head.

[Spreu-boote]

Wow very nice to see your work again

[Livid]

Another month and I've been hard at work. Finishing touches now but I need to be careful to not overlook anything.
The block is back together now and I've been mounting ancillaries. Flywheel pickups, flywheel, CDI box, electrical unit etc. The wiring is a mess but I don't have to look at it so it's all ok haha.

Remaining jobs are fuel pump, oil pump and rebuild the carbs. The parts are on their way on a slow boat from the USA so god knows when they'll arrive. The fuel pump seems ok but it's a cheap part so I might as well replace it, the oil pump left lots of metal particles when I purged it so I'm rebuilding it so I can be confident in its quality. I really don't want to seize the engine up.

I also went and got the stickers put on the cowl, it looks really sharp now, can't wait to turn the key, getting very close now

[jeffstevens763@g]

looking sweet with the new decals

[Livid]

Been very busy, final parts arrived so I've been reassembling the carbs, oil pump and getting the engine on the block.
Attachment 136524
Carbs got rebuilt from the ground up with new seals, floats, needle valves and seats and with the main jets enlarged a touch. Now at 135.
Attachment 136525
Next up was getting the block on the leg and hooking up the tilt motor and switch and oil indicator hooked up as well as some temporary control cables. The battery I had earmarked didn't work so I had to jump start it off my car haha. But it fired first time and after I fixed the mixture screws it started up no problem! Ran for a little and the cooling water came through so that's all good
Attachment 136526
Finishing touches now, I've got to get the bottom carb roller moved and welded because my new carbs are off a pro50 and the roller is in a different spot and jams. Easy enough fix though. The new exhaust makes it sound fantastic!!

[Fenlander]

Always good to get a motor running again. BTW attachments don't show this end.

[Spreu-boote]

Nice to see it is running! Cant wait to see a video!

[Livid]

I forgot to update this over the years! This was the second running apart i put it together, ran very well on the stand

https://vimeo.com/991932517

I got it on the boat in 2021 and it didn't go... great. I got approximately 2 miles before it stopped and wouldn't run right. It turned out to have sheared the flywheel woodruff key clean through and knocked the spark out of time!




That winter I used some valve lapping paste to get the surfaces cleaned up, fresh woodruff key and cranked it down with a big impact. In the 2022 season i found the propulse prop was very disappointing in this application, It bogged down on the launch but also didn't go very quick, so I shelved it in favour of this piece of art from Forge marine



And here it is all fitted on the newly refitted boat!



The new prop made it an absolute animal, the carb tuning definitely could be better, as it will stall at idle very quickly, but I'm tempted to leave it because where it counts it's vicious. My max speed so far has been ~40kt, which is about as comfortable as i feel taking a searider to. If you're not in flat calm and trim it up too much it chine walks and tries to kill you. The aggressive pitch on the prop compromises hole shot a bit, but it's still plenty quick on the plane with two people, if you have 3 or 4 you need to all lean forwards to get it up on the plane

[Livid]

2023 season was arguably even less successful, had to replace the starter solenoid (I kept jumping it with a boost pack for a week whilst I waited for the parts) then a load of bolts rattled loose for the carbs and coils on a run, so i had to tighten them up with rusty pliars to get back home but those were nothing more than a minor inconvenience compared to what happened a bit later on.

I was cracking along pretty much flat out along the fal when the boat snapped really hard to the right and i got pitched over the side. Water's not very inviting at that speed.
When i surfaced I was expecting the rib to be upside down or sinking it was that violent, but nope it was bobbing very happily, didn't even lose my shopping i had in the passenger seat footwell! Seariders are very stable

Climbed back in and saw the engine at a harder angle than i've ever seen it, tried to steer it back straight but the steering was jammed up. Took a closer look and this is what i saw



The steering rod that linked the cable to the tongue on the engine had split open. The engine, unhindered by trivialities like "the direction I wanted to go" and "how fast the boat can turn whilst keeping the people aboard" immedlately torqued all the way over, nice and jammed up.

Fortunately I was able to call my family to come and give me a tow back. My glasses ended up at the bottom of the sea and I was a bit wet and shaken up but not majorly harmed. Some passing sailors also checked I was ok which was very nice of them. Very fortunate to have been wearing a kill cord and life jacket. My dad thanked the kill cord for saving my skin by accidentally dropping it into the sea when putting it back in the boat

Here's a better picture of what happened to the steering rod, it failed through the thin part, not very strong in that area.



I've gone back with another steering rod, but might make the change to hydraulic at some point, it's just on the threshold where that makes sense to do.

Take this as a reminder that even in a boat you're very familiar with the unexpected can happen. WEAR YOUR KILL CORD

[Fenlander]

Nice update thanks. A sheared flywheel key wouldn't have been the first thing you'd normally guess for a no-start.

I've experienced cable steering snapping on a dory at speed and the steering going hard over, we managed to stay in but it was a shock.

[Roflhat]

Hope you get a better season this year!
The V1 cleaver looks absolutely mean on there. Don't think any other searider is running as fast a prop as that.

Seconded on the kill cord, the couple times I've been thrown out of my boat it didn't get too far without me

[Livid]

Originally Posted by Fenlander

Nice update thanks. A sheared flywheel key wouldn't have been the first thing you'd normally guess for a no-start.

I've experienced cable steering snapping on a dory at speed and the steering going hard over, we managed to stay in but it was a shock.

It had fuel, comp and spark, but would only splutter and backfire if it did anything at all when cranking. Didn't find it until I took the engine back to the garage. Was gearing up to strip it all the way down again, was expecting something a lot worse.

My dad had a dory and it never struck me as the most stable thing during hard turning. ngl I'd have imagined the same thing happening on it would have ended up upside down. Definitely is a big shock!

[Livid]

Originally Posted by Roflhat

Hope you get a better season this year!
The V1 cleaver looks absolutely mean on there. Don't think any other searider is running as fast a prop as that.

Seconded on the kill cord, the couple times I've been thrown out of my boat it didn't get too far without me

Fingers crossed but so far so good, needed some minor repairs on the boat as some fabric came loose and was shovelling water into the back (possibly connected with the abrupt stop last year). Can see it in the bottom left of this video

https://vimeo.com/991966740?share=copy

Was absolutely flying last week. was flat calm so i could go ham on the trim, according to my brother who was out in a zapcat there was only a couple feet of the hull in the water. V1 on the searider is a bit quirky but brilliant, it can be nice and controlled if there's a chop out, keep the nose trimmed in and the boat follows the waves with no slamming, but if it's calm and you really give it some it's like shifting into another gear and it takes all the trim it can get.

I might try using a smaller 15L tank and throwing the anchor and cover on the beach to see how quick I can send it if there's another really calm day. Not sure there's much more optimisation I can do without compromising it a lot, already running a very small AGM battery (although it's on my list to move it right up to the nose instead of under the seats). Despite being pretty tuned up it's still great for just going places and doing things as it is now, so long as I remember the octane booster

Need to work on my zapcat engine a bit now. It's been the troublemaker this year. Old rubber engine mounts let go at full speed so I've got to go delrin. The leg also has had some mounting flanges for the cowl break off. Found one on ebay so will strip it down, fit that, design and cnc new mounts then maybe skim the head whilst it's all apart. I forsee another V1 on it in the near future. The 2cyl 40s have so few parts available any more, the 3cyls have loads (also mariner are much worse than yamaha about stocking parts for old engines, if you look up parts for the yamaha version more are available)

[Roflhat]

Wow those mounts really did let go! I took mine to the local machine shop and had them replicate them in nylon. Not that you've got much of the originals left to work with

[Livid]

The originals are quite pricey, 50 quid for the top and 80+ for the bottom on ebay(if you can find them in stock), but i found some chinese ones for 40 for both a top and a bottom mount, good enough to take measurements from. I can get them machined up in the workshop at my workplace, but I think i'll try JLCPCB's cnc machining service, will probably be cheaper and quicker tbh

[tinker]

Great thread, same set up as mine, 4m deluxe and the 3 cylinder yamaha, don't think i will going to extremes you have though, 33 knots is good for me. (Mrs ain't to happy with it though &#128580