Yamaha 200hp Saltwater Series 2-stroke?

[BM]

Rat, the Yam would be a better propostion than the Suzy I believe.

I guess the only way to know how well powered she is, is to go for a run.

I recently serviced a 2003 Haines Sig 530C with a 115Yam 4 stroke on it. They are a weighty hull and a max hp of 130. Seemed a little on the low side to me.

Fair enough Brumby on those readings if youv'e checked em. There would be next to nothing in it in difference between the 175 and the 200.

Cheers

[wadeo]

Hi I run 2 of these outboards on my 7.7 sharkcat. I have found them to be great motors all round. awesome pick up out of the hole and plenty of grunt when i need it. My fuel acconomy at approx 25kn at 3600rpm is approx 32l an hour each and "wot" at approx 45kn is 80l per hour each but generally don't need to use anywhere near 'wot'. On a day out to barwon banks with just over 100km traveled i'd use about 85l each with 5 to 6 people on board. This year outboard also has the ability to charge 2 batteries at once with there aux charging curcuit. I purchased these outboards at a government auction in mint condition for 3600 bucks each with gauges and duel binnicle control. 130psi compression on each cyl of each motor . and in 100hrs of use have only had problems with one fuel pump on one motor (apparently common) . I use castrol 2 stroke oil as my mechanic requests and have no worries. good luck boat looks great.

[wadeo]

Hi I run 2 of these outboards on my 7.7 sharkcat. I have found them to be great motors all round. awesome pick up out of the hole and plenty of grunt when i need it. My fuel acconomy at approx 25kn at 3600rpm is approx 32l an hour each and "wot" at approx 45kn is 80l per hour each but generally don't need to use anywhere near 'wot'. On a day out to barwon banks with just over 100km traveled i'd use about 85l each with 5 to 6 people on board. This year outboard also has the ability to charge 2 batteries at once with there aux charging curcuit. I purchased these outboards at a government auction in mint condition for 3600 bucks each with gauges and duel binnicle control. 130psi compression on each cyl of each motor . and in 100hrs of use have only had problems with one fuel pump on one motor (apparently common) . I use castrol 2 stroke oil as my mechanic requests and have no worries. good luck boat looks great.

[rat_catcher]

Hi rat catcher. Doesn't make a significant difference, just good to know what you are buying. Might be able to talk a few dollars off. Your motor looks in great nic.

Thanks. Still haven't made a final decision. Have been hampered by bad weather in Melbourne this week so cannot sea trial the 702SB.

[rat_catcher]

Rat, the Yam would be a better propostion than the Suzy I believe.

Can you explain this please?

I guess the only way to know how well powered she is, is to go for a run.

A sea trial of the 702SB was planned for this week in Melbourne but due to bad weather has been postponed. I have already sea trialled the 702L last week.

I am in a dilemma now of having to decide which way to go.

702SB with 200hp Yamaha 2-stroke
702L with 250hp Suzuki 4-stroke

There are pros and cons of each and it aint easy to decide!

[leezor]

Rat Catcher,

There is no comparison between the two, chalk and cheese mate! I have recently replaced a 1996 200hp Yammy with a 2007 225hp Suzuki 4 stroke. I was getting around 1km p/l on average with the Yammy and get close to 1.8km p/l out of the Zuke. At WOT I have picked up speed and getting it on the plane is as good if not better than the Yamaha 2 stroke.
Feel free to PM me if you want any more details on fuel consumption etc.

Cheers,

lee

[BM]

Rat,

In a recent conversation with another mechanic mate we were discussing the figures of the Suzuki 4 strokes. Prop size, final drive ratio, rpm. It appears there are some of the opinion that the crankshaft/propshaft offset drive may be a stepped drive and a your 250 Suzuki may indeed only be around 200hp and by the use of a stepped drive they can in effect produce higher power at the prop. Possibly at the expense of greater load on the engine.

However, I must point out this is not proven. Yet

[rat_catcher]

It appears there are some of the opinion that the crankshaft/propshaft offset drive may be a stepped drive and a your 250 Suzuki may indeed only be around 200hp and by the use of a stepped drive they can in effect produce higher power at the prop. Possibly at the expense of greater load on the engine.

Understood. Thanks.

[ALOGT]

I would expect a difference of between 8 to 15 hp with a stepped drive.
When my car has been on a dyno the difference between 4th 201.3hp and 3rd 210.1hp is marginal, I would think an outboard would have a simmilar variation whith different gearing.

Rat,

In a recent conversation with another mechanic mate we were discussing the figures of the Suzuki 4 strokes. Prop size, final drive ratio, rpm. It appears there are some of the opinion that the crankshaft/propshaft offset drive may be a stepped drive and a your 250 Suzuki may indeed only be around 200hp and by the use of a stepped drive they can in effect produce higher power at the prop. Possibly at the expense of greater load on the engine.

However, I must point out this is not proven. Yet

[PADDLES]

BM I don't understand this, hp is hp, you can't create more hp with a different gearing. You can however let an engine rev faster and therefore give greater output and also shift the torque curve a bit. Do you believe that the stepped drive has less losses (mechanical)? I'm asking this out of interest because these suzuki motors seem to have everyone raving about them and I'm very interested in them. (the 140hp model and not the 250hp one)

ALOGT don't be fooled by dynos, there's lots of tricks that can be done with them. In my rallying days my co-driver was a wizz with vehicle dynos and showed me just how inaccurate they can be and how they can be so easily tricked to give a set of curves that the customer will only be too happy to pay a squillion bucks for a performance mod that they didn't really get (they got the mod they wanted but not the performance increase). The trick with dyno's is to exactly replicate each run, ambient temp, barometric pressure, airflow etc. I mean your car will rev harder/easier in 3rd than 4th but you could quite easily do 2 runs in the same gear and get that sort of error.