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Author Topic:   Data log for two years F70 Yamaha

JMARTIN posted 04-03-2012 08:12 PM ET (US)
The results surprised me. The motor was purchased in June 2010 and is on our 1983 Sport 15. I share the boat with my Brother in law.
rpm hours
<1000 19.1
1000-2000 10.6
2000-3000 2.9
3000-4000 10.4
4000-5000 6.6
5000-6000 .3
6000-7000 0

It tops out at 6250 rpm and I have had it there, briefly.
What surprised me was almost 60% of the time was below 2000 RPM. We do not have any stinking no wake zones to contend with. We do not troll with it. My brother in law must just take people out for cocktail cruises. I am willing to bet that all of the over 4000 time is mine.
John
Teak Oil posted 04-03-2012 08:32 PM ET (US)
Thats ok John, someone has to clean the carbon out of those cylinders, and you seem to be doing a fine job of it! Keep up the good work
jimh posted 04-03-2012 09:06 PM ET (US)
RPM---Percent of running time
<1000 = 38.3 %
1000-2000 = 21.2 %
2000-3000 = 5.8 %
3000-4000 = 20.8 %
4000-5000 = 13.2 %
5000-6000 = 0.6 %
6000-7000 = 0 %
This looks typical. You are running at off-plane 59.5 % of the time the engine is running.
jimh posted 04-03-2012 09:20 PM ET (US)
Compare your data with mine from
http://continuouswave.com/whaler/reference/ETEC_EngineHistoryReport.html
I was really pouring the coal to this engine, and the engine history showed 63-percent of the time at off-plane speed.
JMARTIN posted 04-04-2012 12:14 AM ET (US)
Jim,
Either you own a Bass boat, or you are Dave.
I only run the boat 50% of the time. It's a shared boat.
John
Mike Kub posted 04-04-2012 11:32 AM ET (US)
I am considering the F70 for my 16'7" GLS. Would you recommend that?
conch posted 04-04-2012 12:00 PM ET (US)
I am also considering the f70 for a repower. Is this the newer Yamaha 70hp? Is the idle very smooth without shaking? I am deciding between F70 and Evinrude 60hp but unsure of a two cylinder idle and slow speed. Do you have any performance numbers or are they in a previous post? Fuel burn? Weight on transom?
Chuck
DVollrath posted 04-04-2012 12:32 PM ET (US)
Conch,
I had one of the new Yamaha F70 on my 1984 15' Sport until last weekend when I removed it. I could get around 42mph at WOT, measured using a portable GPS. I am very pleased with the motor, and am moving it to my 1988 Montauk. It is very smooth and quiet at idle, and purrs at cruise. You would not be unhappy with the choice.
Dennis
JMARTIN posted 04-04-2012 01:21 PM ET (US)
I would not recommend this motor for a 16'7" GLS. Put a 100 or at least a 90 on it.
It is very smooth at idle, very light on the transom.
Performance figures,
http://continuouswave.com/ubb/Forum4/HTML/007558.html
John
K Albus posted 04-04-2012 01:27 PM ET (US)
Here's a link to the page with the graph of Jim's engine data: http://continuouswave.com/whaler/reference/ETEC250HO.html
andrey320 posted 04-04-2012 02:34 PM ET (US)
What surprises me more is that you've only put 50 hours on your boat in 2 years!
conch posted 04-04-2012 03:47 PM ET (US)
Thanks John, I would prefer the Yamaha F70 but I was trying to justify this repower by re-using my existing controls,harness,and gauges and switching from my 1998 70hp Johnson to a new 60hp Evinrude kind of plug and play. But when dropping 6K-8K I would want everything else to be new also.
I am mainly looking for more range while carrying 12 to 18 gallons of fuel,quiet,and no smoke.This is on an 1983 15 Sport.
Chuck
JMARTIN posted 04-04-2012 04:01 PM ET (US)
I have 6 weeks of beach time to use the Sport and I can only use it if the tide cooperates. My other Whaler gets more hours, but it is used for fishing, overnights, transporting cargo and people out to the islands.
I was surprised at the low hours also.
John
andrey320 posted 04-04-2012 04:12 PM ET (US)
Ahhh... vacation boat and two Whalers... that explains it!
domlynch posted 04-11-2012 07:12 AM ET (US)
Jimh's percentage analysis of rpm/running time looks about spot on to me.
Years ago I bought a 1999 70hp 2 stroke new and ran it up to nearly 1000 hours in 2 years, with full service + taking care of it - eg. warming up, and fresh water flushing at operating temp after each saltwater use (all use was in saltwater). I am very impressed with Yamaha's engineering/smoothness/durability/corrosion resistance etc. One look under the cowling showed (to me) nice clean wiring etc.
I think if you look after your Yammie (whether its a 4 stroke or 2) well she will most likely look after you in return.
Cheers,

Dom
domlynch posted 04-11-2012 07:20 AM ET (US)
Operating between 3 & 4 K, sometimes less, but with some variety, is generally good for an engine - if it is well maintained & if you are happy wih the planing speeds at these rpm (which I think would be very good with a 15 Whaler).
I reckon you would fly with revs approaching 6k or more. I generally only give my motors a brief blast ( say 20-30 seconds each trip, after running at say 4k) at max revs, and mostly operate them at: idle, troll speed (around 3k or so) & a comfortable, non-hull banging speed (say 20knts or so at approx 4k rpm, depending on hull & conditions)
It sounds like you have a great combo and she should serve you well.

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Author	Topic: Data log for two years F70 Yamaha
JMARTIN	posted 04-03-2012 08:12 PM ET (US) The results surprised me. The motor was purchased in June 2010 and is on our 1983 Sport 15. I share the boat with my Brother in law. rpm hours <1000 19.1 1000-2000 10.6 2000-3000 2.9 3000-4000 10.4 4000-5000 6.6 5000-6000 .3 6000-7000 0 It tops out at 6250 rpm and I have had it there, briefly. What surprised me was almost 60% of the time was below 2000 RPM. We do not have any stinking no wake zones to contend with. We do not troll with it. My brother in law must just take people out for cocktail cruises. I am willing to bet that all of the over 4000 time is mine. John
Teak Oil	posted 04-03-2012 08:32 PM ET (US) Thats ok John, someone has to clean the carbon out of those cylinders, and you seem to be doing a fine job of it! Keep up the good work
jimh	posted 04-03-2012 09:06 PM ET (US) RPM---Percent of running time <1000 = 38.3 % 1000-2000 = 21.2 % 2000-3000 = 5.8 % 3000-4000 = 20.8 % 4000-5000 = 13.2 % 5000-6000 = 0.6 % 6000-7000 = 0 % This looks typical. You are running at off-plane 59.5 % of the time the engine is running.
jimh	posted 04-03-2012 09:20 PM ET (US) Compare your data with mine from http://continuouswave.com/whaler/reference/ETEC_EngineHistoryReport.html I was really pouring the coal to this engine, and the engine history showed 63-percent of the time at off-plane speed.
JMARTIN	posted 04-04-2012 12:14 AM ET (US) Jim, Either you own a Bass boat, or you are Dave. I only run the boat 50% of the time. It's a shared boat. John
Mike Kub	posted 04-04-2012 11:32 AM ET (US) I am considering the F70 for my 16'7" GLS. Would you recommend that?
conch	posted 04-04-2012 12:00 PM ET (US) I am also considering the f70 for a repower. Is this the newer Yamaha 70hp? Is the idle very smooth without shaking? I am deciding between F70 and Evinrude 60hp but unsure of a two cylinder idle and slow speed. Do you have any performance numbers or are they in a previous post? Fuel burn? Weight on transom? Chuck
DVollrath	posted 04-04-2012 12:32 PM ET (US) Conch, I had one of the new Yamaha F70 on my 1984 15' Sport until last weekend when I removed it. I could get around 42mph at WOT, measured using a portable GPS. I am very pleased with the motor, and am moving it to my 1988 Montauk. It is very smooth and quiet at idle, and purrs at cruise. You would not be unhappy with the choice. Dennis
JMARTIN	posted 04-04-2012 01:21 PM ET (US) I would not recommend this motor for a 16'7" GLS. Put a 100 or at least a 90 on it. It is very smooth at idle, very light on the transom. Performance figures, http://continuouswave.com/ubb/Forum4/HTML/007558.html John
K Albus	posted 04-04-2012 01:27 PM ET (US) Here's a link to the page with the graph of Jim's engine data: http://continuouswave.com/whaler/reference/ETEC250HO.html
andrey320	posted 04-04-2012 02:34 PM ET (US) What surprises me more is that you've only put 50 hours on your boat in 2 years!
conch	posted 04-04-2012 03:47 PM ET (US) Thanks John, I would prefer the Yamaha F70 but I was trying to justify this repower by re-using my existing controls,harness,and gauges and switching from my 1998 70hp Johnson to a new 60hp Evinrude kind of plug and play. But when dropping 6K-8K I would want everything else to be new also. I am mainly looking for more range while carrying 12 to 18 gallons of fuel,quiet,and no smoke.This is on an 1983 15 Sport. Chuck
JMARTIN	posted 04-04-2012 04:01 PM ET (US) I have 6 weeks of beach time to use the Sport and I can only use it if the tide cooperates. My other Whaler gets more hours, but it is used for fishing, overnights, transporting cargo and people out to the islands. I was surprised at the low hours also. John
andrey320	posted 04-04-2012 04:12 PM ET (US) Ahhh... vacation boat and two Whalers... that explains it!
domlynch	posted 04-11-2012 07:12 AM ET (US) Jimh's percentage analysis of rpm/running time looks about spot on to me. Years ago I bought a 1999 70hp 2 stroke new and ran it up to nearly 1000 hours in 2 years, with full service + taking care of it - eg. warming up, and fresh water flushing at operating temp after each saltwater use (all use was in saltwater). I am very impressed with Yamaha's engineering/smoothness/durability/corrosion resistance etc. One look under the cowling showed (to me) nice clean wiring etc. I think if you look after your Yammie (whether its a 4 stroke or 2) well she will most likely look after you in return. Cheers, Dom
domlynch	posted 04-11-2012 07:20 AM ET (US) Operating between 3 & 4 K, sometimes less, but with some variety, is generally good for an engine - if it is well maintained & if you are happy wih the planing speeds at these rpm (which I think would be very good with a 15 Whaler). I reckon you would fly with revs approaching 6k or more. I generally only give my motors a brief blast ( say 20-30 seconds each trip, after running at say 4k) at max revs, and mostly operate them at: idle, troll speed (around 3k or so) & a comfortable, non-hull banging speed (say 20knts or so at approx 4k rpm, depending on hull & conditions) It sounds like you have a great combo and she should serve you well.