Honda 20 hours

[Cathyalan]

Anybody have an estimate on the number of hours per gallon with the Honda 20 4 stroke? 3/4 and full throttle.

Alan

[Dan]

It depends on how heavily the boat is loaded and what prop you have. The stock Honda prop isn't very well suited to the Telstar, as it is really designed for a much smaller, lighter powerboat rather than a trimaran that weighs in at almost 4000 lbs.

I have a 9.5" x 7" composite Pirahna prop and get about 2/3 of a gallon per hour with the engine at about 2/3-3/4 throttle and about 6 knots or so for boat speed IIRC.

Ron has the 10" x 7" Solas brand high-thrust prop and probably does a bit better. I'd point out that my boat is probably more heavily loaded than Ron's is as well.

[Cathyalan]

Is what you would recommend on this web page: http://compositeprop.com/honda-99-20-hp-ob-c-3_70.html

Alan

[Dan]

Yes, more specifically this one: http://tinyurl.com/28f4r44

Another option would be to get the Honda high thrust prop, which is located at http://www.boats.net/parts/detail/honda ... B92ZA.html

It will give you a higher top end speed and a better cruising speed, but you lose the repairability of the modular Pirahna prop.

Dan

[Ron]

Not sure if I can add anything to this thread. I've never really run the motor for more than about 15 minutes at a time. Only reason for the motor is to get out into the bay and back again. I keep two 3 gallon Honda tanks on the boat and each one lasts about 8 one way trips, but I switch tanks before it even gets close to empty.

I've got both the Solas 10 x 7 4 blade and the Honda 10 x 7 5/8 4 blade. Honda's high thrust is pretty good, but I'd give the edge to the Solas.

[drsm]

Those new props must really make a difference! We used the motor quite a lot last Fall on our cruise up the Lake Michigan shore, and I think we were getting about 5 hours out of a 3 gallon tank running around 4 - 4.5 knots. Our boat was quite heavily loaded. We did discover that raising the center board adds about 0.1 knot while motoring.

Steve

Ron, is this your prop? http://www.cabelas.com/cabelas/en/templates/product/standard-item.jsp?id=0031313017727a&navCount=0&podId=0031313&parentId=&masterpathid=&navAction=push&catalogCode=IA&rid=&parentType=&indexId=&cmCat=netcon&cm_ven=netcon&cm_cat=Google&cm_pla=Solas%2010%20x%207%204%20blade&cm_ite=netcon&rid=2146251080&hasJS=true

[Ron]

Steve -

It could be the same Solas prop (ad says for Yamaha !!!), but below is exactly mine and with a much better price and free shipping -

http://boatpropellers.iboats.com/Honda/ ... =139394615

I like both high thrust 4 blade props - this Solas 10x7 and the Honda 10x7 5/8. They are made for heavier and slower boats. The stock 9 1/2 x 10 pitch is more suited for a light boat that can do 20 knots. After driving the boat for a year with each one, it's probably a wash. The Solas has larger blades but the Honda has a little more pitch. Both of them get me up to 6+ knots at around 3,000 rpm. The Solas may work a drop better (less cavitation) in heavier seas or curent. I bolted the Solas back on just before I pulled the boat to re-evaluate it. Since the boat is in FL and we made it up to NJ, the analysis will have to wait till October.

What RPM were you running at to do 4 to 4 1/2 knots? As I recall, both of the above would be at around 2,000 rpm.

[drsm]

What RPM were you running at to do 4 to 4 1/2 knots? As I recall, both of the above would be at around 2,000 rpm.

I don't know--I haven't installed a tach.

Thanks for the link.