Lightening a V4 Yamaha

[Mr. Demeanor]

I need to reduce the weight of a 1995 Yamaha 130 as much as possible. Every little bit will help. How much will remmoving the oil injection system achieve? Does anyone make a lightweight cowl? Any other suggestions?

[mackeral5]

removing the oil injection isn't going to save much weight other than the oil tank and what's in it, but I guess every ounce will help. you can pull the top cap off your upper cowl and swiss cheese the area under it with a holesaw, again not much but maybe a pound. the older style 3 latch cowls are typically lighter but won't look as good as what you already have. a cut down mid would be the greatest weight savings and likely have a significant impact on how that little boat handles. very nice little 13'er you picked up. it will be interesting to see how drivable it is, being such a small boat it may be better off with a 90 3cyl....

there are quite a few bolt on mods that can be done to that v4, but I doubt it's needed considering your current power to weight ratio...

[Mr. Demeanor]

Ran it for the first time today and it needs some setup work. Motor was buried and steering was extremely heavy. It hit 62 with ease loaded up pretty good with two 200 pound people, 18 gallons fuel, etc. The motor weighs 100 pounds more than the 90 and I would like to make this work as the acceleration is amazing. Probably going to lose the oil injection and move the battery to a more neutral central location. Need to see if I PWC battery will spin the motor.
The wife really liked the idea of having a back seat for pasengers (which helped justify buying it) but with the weight at the transom now, its not happeneing. It stands on it tail getting on plane but I am looking forward to playing withthe setup. Theres a lot more to be had. It looks like 120hp is doable from a 90 which would probably be faster in the end...maybe not as quick though.

[Mr. Demeanor]

So far on the engine itself:
Oil injection system maybe a few pounds.
Short mid section would save ???
Lightened flywheel would save ???
Maybe I will make a run with the cowl off first just to see if it is worth the effort/expense.

[BUSHWACKER]

Go down 1 post see Jason Johnsons setup on his 90 Yama, he did cut his mid, he's running 70mph :eek:

[Mr. Demeanor]

I've been searching around and saw that. Pretty cool. The boats are about the same size too.

[Mr. Demeanor]

Well....I just saw the pics of the boat while I was in it with the 130 and I think I am going to have to go to a hopped up 90. The weight difference is 107 pounds and I think the boat will be much more enjoyable and probably faster. It is sitting about 4" lower than it did when it had a 90. Might even be able to insure it.....maybe :)
Holeshot Video thanks to Ken from Propgods:
http://s201.photobucket.com/albums/aa105/kenuwf/?action=view&current=P1000284.flv

http://img.photobucket.com/albums/v399/MrDemeanor/Boating/P1000281.jpg

http://img.photobucket.com/albums/v399/MrDemeanor/Boating/P1000279.jpg

http://img.photobucket.com/albums/v399/MrDemeanor/Boating/P1000283.jpg

[mackeral5]

you shouldn't have any problem trading a healthy stock v4 for a 3 cyl, assuming you don't plan to keep the v4. maybe even a modded 70hp, if only to help with insurance.

[aeneas]

Very cool boat/engine but it looks like a 3 cylinder would be better. I hopped up my Yamaha 90 to just over 120hp and it is a wonderful screamer revving well over 7500rpm. If you want to go even lighter with a short mid the 'Yamaha 70 ces' is your engine - 110-115hp with 70 on the cowling! :eek:

Jason is the expert on the 90 and Fast Fred on the 70...

Good luck! :smiletest:

[mcyama]

you may want to swap out the old style trim unit and brackets to the new style along for big savings. also revert back to old style top and lower cowling as mackeral5 indicated.

[Markus]

. also revert back to old style top and lower cowling as mackeral5 indicated.

Big weight savings from the old style on the V6, so should be the same for the V4.