Maak sin. Ek het my 17.6 CC Ace op Arabie Dam gehad die naweek met 17 pitch props, rev counters nie gekoppel nie, en 58km/h gedoen (gps reading). Kosi baai loop my duck 4.5m cc,met 90HP Yammie, 6200 rpm (binneland 6000 rpm) 15 pitch, 62km/h. Gaan maar weer die 19 pitch terug sit, 72km/h op 5600rpm.
Hi there Guys, Just bought a new Kosi Cat 16 FC he
- Thread starter AndrePotgieter
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AndrePotgieter
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Hi there all,
Ok I have tested the RPM range without load . Not in the water with muff with water . Idled for 2 minutes then engaged WOT full taps for 2 seconds. Max is still 4000 or 3900. Starting to think this is a RPM Gauge issue and water in Hull. My Wife was driving behind me back from Rbay to JHB and told me tonight that some water was coming out for 300 Km (Piet Retief....)
Willen Winkel spies , Your comment also seems valid perhaps I am doing 5000/ 5500 RPM but not seeing it. I do think the water in HULL is a issue and replacing the 300 bottles with Foam will help is capsized. The Builder has informed me that it will not float correct with bottles in the stern hence they have changed this since 2009. The New regulations requires this and my Certificate is not on spec with new reg.
Ok I have tested the RPM range without load . Not in the water with muff with water . Idled for 2 minutes then engaged WOT full taps for 2 seconds. Max is still 4000 or 3900. Starting to think this is a RPM Gauge issue and water in Hull. My Wife was driving behind me back from Rbay to JHB and told me tonight that some water was coming out for 300 Km (Piet Retief....)
Willen Winkel spies , Your comment also seems valid perhaps I am doing 5000/ 5500 RPM but not seeing it. I do think the water in HULL is a issue and replacing the 300 bottles with Foam will help is capsized. The Builder has informed me that it will not float correct with bottles in the stern hence they have changed this since 2009. The New regulations requires this and my Certificate is not on spec with new reg.
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AndrePotgieter
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AndrePotgieter
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AndrePotgieter
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tacho rpm gauge not properly set up.
a interesting aspect, my one tacho meter is not leka.
the one would indicate 7000rpm at full tapes while the other one says 5500.
so I to have a issue I need to rectify.
but at least my ears are telling me that the rpms are the same
a interesting aspect, my one tacho meter is not leka.
the one would indicate 7000rpm at full tapes while the other one says 5500.
so I to have a issue I need to rectify.
but at least my ears are telling me that the rpms are the same
The motors look fine on the installation settings! The motors are to rich and or throttle setting is incorrect. Do the following test as well, not to be started, gooi the throttle's open, Then check the balance of the carbs intake. Since it is only 2 cylinder motors it is not as forgiving as 3's.
http://faria-instruments.com/site_manuals/IS0012u.pdf
If you are losing water out the boat all the way to Piet Retief, you definately have to find where the water is getting into the hull.
Foam and water dont mix. Problem is that when you take the drain plugs out only the excess water is what you see. The driving and bumping on the road shakes out some of the water that is lodged in the foam.
This situation will only get worse the longer you use the boat. If you spend a week at the coast fishing everyday, the situation will get worse.
If you intend having this fixed it is going to be costly. They have to absolutely find out where the water is getting into the hull and that has to be stopped. Otherwise you will have the same problem with the weight.
As for the motors not revving over 4000 on the test you performed-take it back to Waterworld and have them fix the problem, if you start tweeking on the engines you will probably void any claim you may have.
Seems like two problems then- weight(from the water ingress) and engines not properly set up throttle-rev counter) wise.
I wish you luck and I hope you get this sorted, the hull problem can be a real safety issue and I hope the manufacturer will come to the party as it sounds like they know there was a problem with this specific hull flotation wise.(before 2009) and then changed it or where forced to change it.
I hope this is not the reason the hull was around for so long before they sold it to you.
Foam and water dont mix. Problem is that when you take the drain plugs out only the excess water is what you see. The driving and bumping on the road shakes out some of the water that is lodged in the foam.
This situation will only get worse the longer you use the boat. If you spend a week at the coast fishing everyday, the situation will get worse.
If you intend having this fixed it is going to be costly. They have to absolutely find out where the water is getting into the hull and that has to be stopped. Otherwise you will have the same problem with the weight.
As for the motors not revving over 4000 on the test you performed-take it back to Waterworld and have them fix the problem, if you start tweeking on the engines you will probably void any claim you may have.
Seems like two problems then- weight(from the water ingress) and engines not properly set up throttle-rev counter) wise.
I wish you luck and I hope you get this sorted, the hull problem can be a real safety issue and I hope the manufacturer will come to the party as it sounds like they know there was a problem with this specific hull flotation wise.(before 2009) and then changed it or where forced to change it.
I hope this is not the reason the hull was around for so long before they sold it to you.
willem wikkel spies wrote:
"om 45km/h te kry op daai proppe teen 3900rpm klink nie reg nie."
Looking at this again I agree 100% - incorrect revs showing - I have the exact same motors on my 18' boat and 4000rpm is my normal 'cruising' speed I think its at about 32kph.....my max speed is around 48-50 at 5000-5500.
There is no way you are going to get 45 at 3900-4000 with standatd props.
"om 45km/h te kry op daai proppe teen 3900rpm klink nie reg nie."
Looking at this again I agree 100% - incorrect revs showing - I have the exact same motors on my 18' boat and 4000rpm is my normal 'cruising' speed I think its at about 32kph.....my max speed is around 48-50 at 5000-5500.
There is no way you are going to get 45 at 3900-4000 with standatd props.
dugongboy wrote:
remember he has 2 cylinders,
thus the ignition is not 6 poles as such "shucks, oh well, what I mean is that a 3 cylinder engine has more poles for spark ignition, if tacho is not set up correctly it will not register correct rpm.
André, at what rpm does the motors idle, does it seem to correspond by ear, as indicated by tacho and real life rpm?
yip
remember he has 2 cylinders,
thus the ignition is not 6 poles as such "shucks, oh well, what I mean is that a 3 cylinder engine has more poles for spark ignition, if tacho is not set up correctly it will not register correct rpm.
André, at what rpm does the motors idle, does it seem to correspond by ear, as indicated by tacho and real life rpm?
WWSpies, this was one of my first, maybe third questions on revs (tacho). And I agree with you comment, The performance of Andre's boat compare well with other boats posted.(obviously not the rpm range, but speed wise, thus the tacho,s is not set correctly, weather new boat or not. The dealers feels poof for a new buyer!
To Andre, if I where you, I would go back to WW and let them sort this out!
To Andre, if I where you, I would go back to WW and let them sort this out!
AndrePotgieter
New member
100 % guys Thanks , I will be taking the boat back there tomorrow.
I definetly believe your gauges are reading incorrectly.
Using a prop slipage / rpm / speed formula, i get your boat rpm's at 5500rpm @45kph. Which is perfect.
The formula:-
rpm 5500 divide by 2 (as 2:1 ratio gear case) = 2750
2750 x 12 pitch (12" forward movment per 1 revolution) = 33000 inches per minute. = 50,3kph
- 10% prop slipage (this is a rough guess) = 45kph @ 5500 rpm.
I cant comment on the weights, but they dont look too far off?
physically impossilble for your boat to travel 45kph @ 3900 rpm.
Using a prop slipage / rpm / speed formula, i get your boat rpm's at 5500rpm @45kph. Which is perfect.
The formula:-
rpm 5500 divide by 2 (as 2:1 ratio gear case) = 2750
2750 x 12 pitch (12" forward movment per 1 revolution) = 33000 inches per minute. = 50,3kph
- 10% prop slipage (this is a rough guess) = 45kph @ 5500 rpm.
I cant comment on the weights, but they dont look too far off?
physically impossilble for your boat to travel 45kph @ 3900 rpm.