Reply
 
Thread Tools Search this Thread
 
Old 12 June 2014, 08:43   #1
Member
 
Country: Canada
Town: halifax
Boat name: white water
Make: zap cat
Length: 3m +
Engine: 50hp tohatsu
Join Date: Jun 2014
Posts: 31
tohastsu 50 hp needs to go faster

Hey iv got a 50hp mxd2 2013 .tohatsu. on a 14ft zapcat .
Iv got it going 45mph. But still far from what I want for speed
Iv got a D1 exausts
And a 10.2 x 15 ss prop
My reves 5100 wide open
Q: what els can I do for speed

Thanks joel babin
__________________

__________________
itrjoel is offline   Reply With Quote
Old 12 June 2014, 09:49   #2
Member
 
Country: UK - England
Town: Hoxne
Boat name: Southern Comfort
Make: NorthCraft 5.5
Length: 5m +
Engine: 150 Optimax
MMSI: 235033276
Join Date: Nov 2005
Posts: 122
Send a message via MSN to Under the Thumb
The list is practically endless, but to start with, you can look at proper setup in terms of

Cheap and easy

Engine height - centre line of the propeller needs to be in line with the hijacker inflation valves or a tiny bit higher.
Trim
Is 5100 on the rev limiter? or are you not getting full revs

Then on to the expensive bits - new prop, engine mods, prop modifications

Huge information resource here - Australian Thundercat Forums
The Setup Thread - Thundercat Inflatables Forum

You also need to work out how often you're going to be doing 45+ and whether acceleration and handling is more important than straight line speed on a mirror flat day.
__________________

__________________
Northern Exposure Rescue

Marine Safety / Photography / Event Management
www.northernexposurerescue.org.uk
Under the Thumb is offline   Reply With Quote
Old 12 June 2014, 11:06   #3
Member
 
Country: Canada
Town: halifax
Boat name: white water
Make: zap cat
Length: 3m +
Engine: 50hp tohatsu
Join Date: Jun 2014
Posts: 31
Hey no thats not the revlimitor
It just wont rev past 5100 with 2 guys on board ill check the engine hight tonight
Dose this motor need jets and reeds and send this ss prop Away....
prop sending away ....

What I dont understand about sending the prop away.... how woluld they know how much to remove with out being able to test ever boat and motor r differnt...if to much is removed it will be f'd if not enough is removed ill be paying money and left with the same problem ...
__________________
itrjoel is offline   Reply With Quote
Old 12 June 2014, 14:07   #4
Member
 
Country: Canada
Town: halifax
Boat name: white water
Make: zap cat
Length: 3m +
Engine: 50hp tohatsu
Join Date: Jun 2014
Posts: 31
My prop is
Pro Tech 10.25 X 15 REB3R15P.
__________________
itrjoel is offline   Reply With Quote
Old 12 June 2014, 16:10   #5
Member
 
spartacus's Avatar
 
Country: UK - Scotland
Town: Aberdeenshire
Boat name: Sula
Make: Ribcraft 4.8m
Length: 4m +
Engine: Tohatsu 60hp + aux
MMSI: 235087213
Join Date: Jun 2007
Posts: 3,267
RIBase
You might want to read this... http://www.rib.net/forum/f50/my-thundercat-61912.htm
__________________
Is that with or without VAT?
spartacus is offline   Reply With Quote
Old 13 June 2014, 05:10   #6
Member
 
Roflhat's Avatar
 
Country: UK - Scotland
Town: Isle of Lewis
Make: Ceasar Thundercat
Length: 4m +
Engine: Yamaha 70ces
Join Date: Jul 2010
Posts: 633
RIBase
Quote:
Originally Posted by Under the Thumb View Post
Then on to the expensive bits - new prop, engine mods, prop modifications

Huge information resource here - Australian Thundercat Forums
The Setup Thread - Thundercat Inflatables Forum
Quote:
Originally Posted by spartacus View Post
These are both good things to read (I started both of them ). My thundercat
45mph is about right for a 15p bunny prop. Maybe a bit slow, I was getting 49mph with my 15p prop, although it was cupped.
Once you start going for speed you really want a surface piercing propeller, chopper or cleaver.
The best starting point is trying to get max rpm with the prop you've got.

You should be getting more revs, the limiter is set at 5850. To get more rpm raise the engine up. If you're prop is cavitating you want to get it cupped for more grip.

Most of your performance gains are done by propeller selection. If you still can't get the speed you're after then start engine modifications.
Saying that, a set of boyesen carbon reeds is good on any engine. If you want more noise as well as speed you could do the exhaust mod - a 1" hole in the gearbox so the exhaust gases don't exit through the prop. Lighting coils can be removed from beneath the flywheel, frees up some hp.

Try and get some photos up of your propeller, engine set up, trim etc.

You can see here I ran a bit of orange string across the bottom of the hijackers to give an idea of prop height. This was with an 18p chopper, a 15p bunny should be lower.
__________________
Roflhat is offline   Reply With Quote
Old 13 June 2014, 11:48   #7
Member
 
Country: Canada
Town: halifax
Boat name: white water
Make: zap cat
Length: 3m +
Engine: 50hp tohatsu
Join Date: Jun 2014
Posts: 31
So ... I checked my engine hight .. and the nut that holds the prop on is in line with the high jacker inflation valve
Are you saying keep raising the motor tell it
Cavatates then back down a lil so its not ...???
Im so lost with this stuff normally a car guy ..
Thanks joel
__________________
itrjoel is offline   Reply With Quote
Old 13 June 2014, 18:20   #8
Member
 
Roflhat's Avatar
 
Country: UK - Scotland
Town: Isle of Lewis
Make: Ceasar Thundercat
Length: 4m +
Engine: Yamaha 70ces
Join Date: Jul 2010
Posts: 633
RIBase
That sounds about right, your engine might already be too high.
Sounds like you're down on power, is it firing on all 3 cylinders?
__________________
Roflhat is offline   Reply With Quote
Old 09 March 2015, 07:01   #9
Member
 
Country: Canada
Town: halifax
Boat name: white water
Make: zap cat
Length: 3m +
Engine: 50hp tohatsu
Join Date: Jun 2014
Posts: 31
50hp tohastu everrun speed!!!!

hey guys/girls.
iv got a 14 ft zapcat with a 10.25 x15 prop on my 50 hp . and can only get 50 mph top speed and it seems most of my friends are doing 60 mph .. id like to bye a new prop somthing like a cleaver 10.25 x 18 ...or somthing im not 100% what i should get .. alls im looking for is speed nothing els.
thanks
__________________
itrjoel is offline   Reply With Quote
Old 09 March 2015, 07:30   #10
Member
 
spartacus's Avatar
 
Country: UK - Scotland
Town: Aberdeenshire
Boat name: Sula
Make: Ribcraft 4.8m
Length: 4m +
Engine: Tohatsu 60hp + aux
MMSI: 235087213
Join Date: Jun 2007
Posts: 3,267
RIBase
Checkout posts by Roflhat. He's mangled to get to warp speed by rebuilding his Tohatsu, Yammie carbs, different prop, etc.
__________________

__________________
Is that with or without VAT?
spartacus is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 04:02.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.