Yamaha 130 V4 Project Build.

[Mr. Demeanor]

So.....


Good news and bad news.

The good news is I picked up 200 rpm cutting the tuner! Lost a little below maybe 4500 where is feels a little "soft" now but no problem breaking the prop loose and jumping up on plane. Big gain up top though. 2.5mph which in theory puts me over 100mph.

And now the bad news. My lightened flywheel came apart at about 5500-6000rpm and did some damage. The ring gear seperatated and fell down destroying the stator, timing advance, ate some of the starter, etc. What worries me is there are metal shavings all over. When it went the motor immediately shut off but Im worried I ingested some metal. It was raining when I got home so I parked and took nap

Ill take a closer look tomorrow.

First time being towed. Luckily there was another ramp close by.

Big thanks to Mike M. (DagoDiver) for the tow and going to get my trailer.

[DoktorC]

Ya...that's a bad day...be glad that it didn't hit you in the head! It's really not that far away lol.

[CharlieN]

Be glad that ring is round and just the center failed.
The mechanicals can be fixed.

[Mr. Demeanor]

Yup its just parts. Im going to pull the intake and see if there's any metal shavings present.

She really woke up over about 4500rpm. I was all smiles for about 10 minutes.

[Mr. Demeanor]

This is what I get when I plug in the new numbers with my top end prop.
Can I call it a 100mph boat or do I have to actually do it?

[davemvegas]

you have to do it to make it count. and that you already know. but i agree it looks good on paper.

[Mr. Demeanor]

you have to do it to make it count. and that you already know. but i agree it looks good on paper.

I looks safer on paper :-)

[CharlieN]

The boat and motor do not know the difference between 95 and 100. The boat does not know of any magical limit. Only you know what the boat is telling you when it is up at speed, it is easy for all of us to just say go do it. To me if the boat felt good from 90 to 95, I expect it should feel fine through the next step up, unless you can sense that may not be the case. If it might not be the case then you should not go there.
Remember back in 1999 all the stupid talk of what was going to happen, nothing did. So is 99.9 any different?

[davemvegas]

I looks safer on paper :-)

try for 100 at the Suwanee in nov. water is not that cold when you go in with a adrenalin rush.

[Mr. Demeanor]

try for 100 at the Suwanee in nov. water is not that cold when you go in with a adrenalin rush.

I'll put the big prop on next month at the Suwanee run if conditions look right.

[Mr. Demeanor]

Got it all apart yesterday after quite a battle with the flywheel. Took a puller, bottle of map gas, penetrating oil, and an air chisel to get the flywheel off.
When I pulled the flywheel, 3 magnets stayed on the stator. I kind of wonder if one had come loose and sent the flywheel on a path to self destruct.

The stator and trigger ae destroyed. There is a good grind mark on the top bearing housing but it should be fine. I dont think you can remove that cap with splitting the cases.

Ill pull the intake and inspect for any fragments but I think I am okay. I swabbed the carb throats with cotton swabs and found no metal.

[baja200merk]

You can remove the cap. Ive swapped omc to yamaha a few times just by loosening the top CC bolts.

If you need any yamaha ignition stuff I've got an old timer around the corner with a few containers full of it.

[Mr. Demeanor]

You can remove the cap. Ive swapped omc to yamaha a few times just by loosening the top CC bolts.

If you need any yamaha ignition stuff I've got an old timer around the corner with a few containers full of it.

Thanks buddy. Ill let you know.


I found all the large metal parts I was worried about and even though there was shaving everywhere I checked the intake, reeds, etc and cant find a speck. Scoped the cylinders and they look fine so I think I lucked out in that respect. I did see Im still running a little rich even with the cold weather and coming down in jet size so theres a little more power there keeping the jetting safe.

[Mr. Demeanor]

Found a PRISTINE fresh water flywheel and stator looks like brand new Im buying.

You know the flywheel new now is like $1000, stator is $700, and trigger is $350.....WTF???????????????????

[XstreamVking]

Price of parts is going crazy for all the motors.....Good thing you didn't hurt anything else.....