Questions To The Experts

Manos
24 April 2003, 17:55
Ok guys I am having the boat ready for the race on the 18th May 2003 in Greece, however there are some questions that bother me and thought that you may be able to assist.

1. Because of the engine being a VMax I can either enter the boat to the sport up to 200 bhp category or to the leisure up to 225 bhp category.
I thought about that one hard and if the boat is entered in this sport cat and the engine is not modified then it will not be able to compete with the modified boats.
If I enter the 225 leisure cat I recon that it may have a chance to finish in a good place. However it may be difficult to compete with boats having a Merc 225 since this engine is 3ltrs+ and my engine Yam VMax 200 is 2.6 ltrs.
Any ideas??

2. The prop question also comes up. The min LOA is 5.85 and min weight 580 kgs. The boat with all the gear (as per Greek Coastguard regs) onboard i.e
2 anchors (chains 1x30 mtrs, 1x7 mtrs, ropes 1x50 mtrs, 1x30 mtrs), aux engine, 11 life jackets, life raft, spare ropes, flares
1st aid kit, oars, 170 ltrs petrol etc etc I recon that it will weigh about 700-800 kgs.
Currently prop is 21" pitch SS Yamaha Pro, boat hull length 6.1 mtrs, length in the water 5.80 mtrs, engine revs at 5700 and gets between 52/55 knots. Any advise to get it going a bit faster so that it can compete with the Merc 225s??

That's it faulks.

Any advise, info is gratefully received!! ;)

PS some details about the race. The race is 60 miles in total. Starts from Kalamaki, goes via San Giorgio and then back.
The race will be covered by the Greek RIB mag and photos will be duly posted (even if I sink the boat LOLOL =) )

kitten
27 April 2003, 10:48
Manos, The quickest easiest way to make the boat more racable is to fit a foot throttle and put a bungie or something on the gear lever to stop it jumping into neutral,or move the hand throttle to where the navigator can control it for you(like a C1 boat). this will also save your powerhead from over reving and ultimatly blowing up. Try to eliminate any rattles or knocks from anywhere on the boat, especialy in the leg as small amout of backlash here can turn into broken bits very quick if you're fast in the rough. Take the best prop you got and go out and experiment with moving all that kit you got to change the c of g and lateral balence not forgetting to secure it and protect your boat then be ready to change it all on the day if the conditions change, probably as far back as you can in the flat, and futher forward in the rough. there are no hard and fast rules as to what prop goes despite what the 'experts' will tell you guidelines is the best way to describe them. A mate of mine had a consistant 75 mph prop untill someone polished it with a rag and some wax then it only ever gave him70 despite cleaning off the polish, go figure. testing and tweaking one thing at a time is the only way. Enter the leisure category or get your engine blue printed and fitt a low water pickup, and I don't think you have time.
Hope this is some help.