Jet Drive

[phil959]

can anyone tell me if i reduce the size of the nozzle will this inprove poformence on a pp90 jet nozzle is 6inch dia this looks to be quite big for a 9 inch impeller.i see hammilton jets look quite a bit smaller that is looking at pics.and thanks cyclops for your help. phillip

[jetboatjill]

Phillip,
Cyclops is tremendous help & extremely knowledgable! He helped us get our jet boat up & running! Let me talk to johnnyjetboat (my main squeeze) and we'll get back w/ you ASAP.......but for now, take Cyclops' advise! :-) jetboatjill

[cyclops]

Just to give you a idea how critical front to rear weight is on speed. I have a 18.5' bow rider 8' wide 3400# 250hp 5.0L . 2 people in mid boat it needs full trim in to get up on plane. Then trim out as speed increases. ORRRR. 1 person, 150# at the point of the bow and it needs no trim in to plane. Boats are on water, Not roads. You HAVE to experiment with weight and trim to live with what you have. ORR. Get the help of a winner in a racing boat similar in size and shape to what you have and let him test it and show you how to do it. ORRR. Tell you what is wrong and how to fix the problem. --------Note, my boat can not plane with 5 people in the rear. NO WAY, NO HOW. TOO much weight back there.

[Big-A]

what kind of jet system can i hook up to a 1979 dogde 440

[phil959]

can anyone help i had 200 hp diesel driving pp 90 jet at 2500 revs with the steepest pitch impeller only got 15 knotts i have now got 165 hp at 3600 reves a much lighter engine but now prop is to big and only rev at 2400 but i still do 15 knotts if i buy the right impeller to let engine rev at max 3600 revs do you think this will improve my speed .i have 21 foot deep v hull it will do 40 knotts with 225 outboard.hope sombody can help
regards phillip

[brian eiland]

Originally Posted by phil959

can anyone help i had 200 hp diesel driving pp 90 jet at 2500 revs with the steepest pitch impeller only got 15 knotts i have now got 165 hp at 3600 reves a much lighter engine but now prop is to big and only rev at 2400 but i still do 15 knotts if i buy the right impeller to let engine rev at max 3600 revs do you think this will improve my speed .i have 21 foot deep v hull it will do 40 knotts with 225 outboard.hope sombody can help
regards phillip

I don't claim to be any kind of an expert in this subject, but I am presently looking at the jet powered subject for another RIB application. I have noticed some references to problems with proper intake of fluids when the jet unit is mounted in a 'deep V' hull form. Do you know the deadrise angle of your hull at the inlet location??