1978 Wellcraft with 4 blade prop, not the speed I was expecting

[89cruisers]

Re: 1978 Wellcraft with 4 blade prop, not the speed I was expecting

I will probably bring it up to 5 tomorrow if I get to it, that test was with other plugs in, and throttle closed, and since they are all similar, im sure compression is fine since it did not use any oil, and was having an acceptable about of blow by coming out the oil fill when ran at WOT, have not checked the advance in the distributor, will have to try to google that then.

 

[steelespike]

Re: 1978 Wellcraft with 4 blade prop, not the speed I was expecting

Well but with an engine, if im doing 3k rpms, based on rpms alone shouldnt the fuel consumption be the same no matter how much weight or my ratio, 3k rpms is 3k rpms, or am I wrong?

Your right the motor will use about the same amount of fuel at wot whether turning 3000 or 4,600.
A 188 will use about 18 gph (gallons per hour)at wot. if your only making 3,000 rpm instead of 4,600 I think you can see your gph is the same but the distance will be signifigantly less.
Then of course there is the extra strain on the motor.

 

[89cruisers]

Re: 1978 Wellcraft with 4 blade prop, not the speed I was expecting

well my thought was that if the pistons are only going 3000 rpms at WOT, wouldn't it be using less fuel than at 4600 WOT, if they are spinning at 3000, they should only use 3000 worth of fuel, not that same amount of fuel as 4600? so what im saying is if this problem is only gear related, then this boat would be more efficient by not letting me use 4600rpms worth of fuel?