which 90hp 2 stroke?

[ericcs]

i have a 99 5m quintrex seabreeze with a 70yam 2st and want to upgrade to a 90 2st (second hand), while the 70 runs sweet and pushes the boat fine, i would like a bit more top end speed. while a 90 yam would be the obvious choice as the 70 controls are the same, i hear they are only rated at 82hp(the 10% fudge factor) where as the merc with it's larger capacity is almost on the money, albeit with a weight penalty. sentimentally, i would like a v4 omc, but have already been spooked by a faulty vro pump on a 60hp($4k rebuild)
any thoughts
regards
eric

[Fed]

I'd go with the 70HP Eric.

[nigelr]

I've got a 90 on a 5.3m; only went the 90 for bar crossing.
70 or 90, Tohatsu is def worth a look IMO, I love mine!

[Noelm]

I think you have covered the pros and cons yourself, the Yamaha is as light as a feather (don't believe the 82HP crap) but it is a small displacement engine, plus the added bonus the controls and stuff you have will all fit, the Merc is a big displacement engine, plenty of power and run well, only option left is a Tohatsu I guess, which is kind of between them both. The OMC V4 is the pick of them, (for power) just because you had a bad experience with one once, does not make them all bad, the VRO is a simple device that has been in use for years, and to a point, they all use a system that is similar.

[Noelm]

OH, and I dont think you will pick up much more speed with a 90 Yamaha over a 70, it will only be a small difference.

[ericcs]

OH, and I dont think you will pick up much more speed with a 90 Yamaha over a 70, it will only be a small difference.

your probably right about the top speed. apart from needing the extra grunt occassionally when the kids want to wakeboard, it's those days when you can see moreton island in the distance, the bay is like glass, you just want to nail it and get there quick. satisfying the boy within i guess.

with the OMC's, we have owned only evinrudes since 75, but only smaller non VRO engines, except the 60 which had blown up on the previous owner. he provided the repair receipt on purchase and ran it on premix after that. i have been looking out also for an OMC(preferred choice), but the majority i have come across, have had the VRO bypassed as a precaution. i am just trying to steer clear of this, as i don't want the potential hassle of having to remove up to 80l of stale fuel from under the floor.

a friend of mine who is a very pro OMC/BRP dealer and service tech, but sells more yamaha's(not by choice) reckons the problems with the VRO pumps comes down to maintenance issue. so, isn't there supposed to be a warning buzzer that's sounds first, alerting to impending disaster, and is there any real preventative maintenance that can be done to stop the potential problem from developing in the first place, other than checking for obvious signs?

cheers
eric

[Fed]

Don't fear the VROs.

2 alarms on them, one for low oil in the bottle & one for no oil being delivered to the fuel.

Interestingly OMC say that if you get a 'no oil' alarm don't operate the motor above 1500 RPM.

Test the alarms.
Don't put water or dirt into the bottle.
Run on premix for a short time to confirm proper VRO oil usage.

That's about it, I've been running a 1988 VRO for 5 years and haven't looked at it since it was first commissioned as above.
I do put oil in it and carry a spare 1 Litre bottle in the boat.

[Noelm]

the later VRO system (actually called OMS) is very reliable, just as reliable as any other makers system, the practice of disconnecting the VRO is wide spread and often done, however, it is also done my paranoid mechanics who really have no idea! if you could find a late model OMC V4 90/115HP in good condition, that would be my choice for what you are after, going to a 90 Yamaha is going to give you little gain, a late model Mercury would also be OK, but there is not many for sale, whether that is due to them not selling many new, or whether people keep them forever is any ones guess.

[ericcs]

the later VRO system (actually called OMS) is very reliable, just as reliable as any other makers system, the practice of disconnecting the VRO is wide spread and often done, however, it is also done my paranoid mechanics who really have no idea! if you could find a late model OMC V4 90/115HP in good condition, that would be my choice for what you are after, going to a 90 Yamaha is going to give you little gain, a late model Mercury would also be OK, but there is not many for sale, whether that is due to them not selling many new, or whether people keep them forever is any ones guess.

can you tell me what year the OMS system came in, did the evinrude ficht engine run alongside the johnson carb model. were there any relibility issues with ficht's?

[Noelm]

OMS came in araound '94 I think, the Ficht was still available when the carby models were around, any FICHT you buy will want to be very cheap, as they have next to no re-sale value, however, the 90/115 V4 was a very good motor, but they weigh a tonne (well 170KG actually) which is heavy for a 2 stroke 90! from memory, the Evinrude was the FICHT, and the Johnson was carby, but I could be wrong on that. If you care to visit any US sites and do a FICHT search (and even here to an extent) you will find a thousand threads about them, the V6 early models gave them a very bad name, and it is often said that it sent OMC broke, however, FICHT was only a tiny bit of the puzzle, they were going under a long time before then.
have a quick read here about VRO and the mistaken myths about it
http://continuouswave.com/whaler/reference/VRO.html

[Noelm]

I reckon for what you want, forget the FICHT, the weight is going to kill you on your boat.

[Fed]

You can drill down at the BRP website to answer most of your questions.
http://epc.brp.com/SiteMods/BRP_Publ...8-3daa90d94d3a
I'd steer clear of the Ficht purely because of it's orphan status.
1988 V4 90HP long shaft PT&T weighs 301Lbs, 136.5 Kgs so the later ones would be very much the same.

I'm surprised you want to change I think the 70 on your boat would be nicely balanced. Revhead?

[joey_1987]

Yamaha does in fact output 83.8hp @ 5000rpm, it used to be sold as an 85hp model but yes 10% rule allows them to brand it as a 90. Tohatsu 90hp 88.7hp @ 5250rpm from 1267cc but weighs more than the Yamaha by circa 16kg. The Merc has more cc's but these come with weight, 1386cc but about 17-18kg heavier than the Yamaha. I found this article for you which is 12 years old but compares the outboards you're after.
http://boatpoint.com.au/engine-revie...-90-130hp-8111

[Noelm]

the 85HP Yamaha existed as a CV model, this is a mix your own fuel, the 90HP came in oil injection, a stainless prop and a few other goodies.

[Noelm]

I guess to a point, it has come down to nit picking, I said right at the start, the 90 Yamaha will be of little benefit over your 70, the best motor for your needs would be the V4 90/115 OMC, then the Mercury (being the next biggest displacement) or just put up with what you have and save the dollars.