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snappertapper
08-11-2002, 01:52 PM
what exactly do vent holes do, will they stop cavitation in ruff water?

TOBTEK
08-12-2002, 06:58 AM
snappertapper:
what exactly do vent holes do, will they stop cavitation in ruff water?I was at DCB last week and was asking the same question about the big holes in the prop. I was told that the exaust will exit the holes to help blow out some water,helping the motor to rev quicker. Helping the boat get onto a plane faster. Pretty sure that what he said..... :rolleyes:

HavasuDreamin'
08-12-2002, 08:36 AM
This has to be on a thru hub prop right?

Whatboat
08-12-2002, 12:42 PM
[QB][QUOTE]Originally posted by snappertapper:
I was told that the exaust will exit the holes to help blow out some water,helping the motor to rev quicker. Helping the boat get onto a plane faster.
Thats what they do. Cruising speed to top end they do nothing.

RASTA
08-12-2002, 03:58 PM
SNAPPERS RIGHT AGAIN.

TOBTEK
08-12-2002, 05:24 PM
[QUOTE]Originally posted by HavasuDreamin':
[QB]This has to be on a thru hub prop right?[/QBH/
H/D.....OK, here's the hot setup for the 2.4 bridgeport motor like you have. Get a brandnew blueprinted/lab finsh MERC 28 or 26 round ear chopper over hub exaust. Measure 4 3/4 inch from center hub, pinn small area 3/4 from outside dogear. Drill 1" hole's with door knob saw from HOME DEPOT (make sure you carbide bit) this will help in all ways. easier starting, better holeshots,better fuel range. this helped my big end by 5mph alone. If I where you id get off the computer right now and get drilling!
ROTFLMAO.......yes, only thru-hub exaust. Have you got your motor starting better?....toby :D
BTW, the new 2003 MACH22 300-X IS ON ORDER! TAKING DELIVERY AROUND JUN/JULY...CANT WAIT
[ August 12, 2002, 06:27 PM: Message edited by: TOBTEK ]

COUGARMAN
08-13-2002, 04:02 PM
Run this drilling holes in prop to get 5 mph again.This does not seem possible.Somebody help me here.Do I have a witness!
COUGARMAN

nhbuoy
08-13-2002, 04:38 PM
HEY COUGARMAN/SNAPPERTAPPER >>>>> The vent holes DON'T give you more top end, they are to ventilate the prop (thru hub only) to get a better hole shot...(I doubt TOBTEK gained 5 mph,I think he's pulling your leg)....I'm also not sure 1" holes are the correct size, it seems a tad big??? The procedure is PICTURED in the OMC SEYLOC manuals...trying to describe the correct drilling location is confusing to say the least...Is this an outboard or IO ?????

snappertapper
08-13-2002, 04:59 PM
225 yamaha saltwater series, i was jsut curious if they help stop cavitqtion but i guess not!!

nhbuoy
08-13-2002, 05:41 PM
HEY SNAPPERTAPPER.......If it's cavitating in rough water and/or in turns the motor might be mounted too 'high' on transom....Have you thought about relieving the exhaust????? Maybe there is TOO MUCH exhaust for the prop to deal with????

TOBTEK
08-13-2002, 06:03 PM
TOBTEK:
[QUOTE]Originally posted by HavasuDreamin':
[QB]This has to be on a thru hub prop right?[/QBH/
H/D.....OK, here's the hot setup for the 2.4 bridgeport motor like you have. Get a brandnew blueprinted/lab finsh MERC 28 or 26 round ear chopper over hub exaust. Measure 4 3/4 inch from center hub, pinn small area 3/4 from outside dogear. Drill 1" hole's with door knob saw from HOME DEPOT (make sure you carbide bit) this will help in all ways. easier starting, better holeshots,better fuel range. this helped my big end by 5mph alone. If I where you id get off the computer right now and get drilling!
ROTFLMAO.......yes, only thru-hub exaust. Have you got your motor starting better?....toby :D
BTW, the new 2003 MACH22 300-X IS ON ORDER! TAKING DELIVERY AROUND JUN/JULY...CANT WAITYES I WAS ONLY JACKING WITH H/DREAMING!!!!!! dont go drilling a good prop! :D

HavasuDreamin'
08-14-2002, 06:11 AM
TOBTEK:
[QUOTE]Originally posted by HavasuDreamin':
[QB]This has to be on a thru hub prop right?[/QBH/
H/D.....OK, here's the hot setup for the 2.4 bridgeport motor like you have. Get a brandnew blueprinted/lab finsh MERC 28 or 26 round ear chopper over hub exaust. Measure 4 3/4 inch from center hub, pinn small area 3/4 from outside dogear. Drill 1" hole's with door knob saw from HOME DEPOT (make sure you carbide bit) this will help in all ways. easier starting, better holeshots,better fuel range. this helped my big end by 5mph alone. If I where you id get off the computer right now and get drilling!
ROTFLMAO.......yes, only thru-hub exaust. Have you got your motor starting better?....toby :D
BTW, the new 2003 MACH22 300-X IS ON ORDER! TAKING DELIVERY AROUND JUN/JULY...CANT WAITYou a funny guy :D
Didn't have any problems with the motor the last couple of weeks. My new process is, juice it with some starter fluid, quarter down on the throttle, prime once and light! Has worked well for me so far!
Congrats on the new DCB purchase! PS: Don't look at the classifieds any more or you will see the boat you were looking for........Murphy's Law wink

burbanite
08-14-2002, 09:31 AM
HavasuDreamin'
Didn't have any problems with the motor the last couple of weeks. My new process is, juice it with some starter fluid, quarter down on the throttle, prime once and light! Has worked well for me so far!I damn well knew it! Everytime yours starts OK mine doesn't
:rolleyes:
After you left the island on Sunday I hung around for a while longer and yep, you guessed it!
Pushed off, cranked it over and same old story. Remember my "cooling" experiment?, it had allowed the plugs to load up and it was deja vu all over again. WFO in the idle zone = 1500 RPM! A few more cylinders caught up making a total of 6 and thats the way it went back to the ramp - sure was funny if you weren't me :)

snappertapper
08-14-2002, 03:41 PM
well this is on my gilnet boat , im not sure if you hve ever seen on but it has a well in it and the motor is towards the bow thus it cavitates when in ruff water or when turning to the right real sharp!

HavasuDreamin'
08-15-2002, 12:37 PM
burbanite:
HavasuDreamin'
Didn't have any problems with the motor the last couple of weeks. My new process is, juice it with some starter fluid, quarter down on the throttle, prime once and light! Has worked well for me so far!I damn well knew it! Everytime yours starts OK mine doesn't
:rolleyes:
After you left the island on Sunday I hung around for a while longer and yep, you guessed it!
Pushed off, cranked it over and same old story. Remember my "cooling" experiment?, it had allowed the plugs to load up and it was deja vu all over again. WFO in the idle zone = 1500 RPM! A few more cylinders caught up making a total of 6 and thats the way it went back to the ramp - sure was funny if you weren't me :) Damn...........what do you think the problem is? Not all dual quad motors are that hard to start are they? You seem to be fouling plugs even quicker than I do. :confused:

burbanite
08-15-2002, 03:34 PM
HD,
the thing doesn't like to idle too long, if it does then the plugs get fouled. This makes it hard to start next time, thats why I got into the habit of changing plugs after each day and investing in that pneumatic plug cleaner.
In this instance it was the fact that I was running the engine so cold and it sat for a long time before firing up again. I am going to move up one step in the heat range as a test. Thing is that the plugs look ok when running normally (I've checked this).
If you recall we were discussing the manifold at the weekend. I think, (apart from anything else), is that it doesn't distribute the fuel well at low rpm, it is always the corner plugs that are fouled, the rest are fine.

burbanite
08-15-2002, 03:45 PM
Funny thing to discuss in the outboard forum....... some people around these forums don't think that having a boat that is different from theirs is acceptable.
Hey, if you try really hard you could get to 1000 posts before you go awol for a little while:D
Hope all is going well for you both, remember - have fun, its your day.

HOSS
08-18-2002, 05:43 PM
We would drill these holes at the OMC dealership I worked for. The do cause cavitation at lower rpm`s to get the motor into its powerband therby getting you out of the whole and on plane quicker.

HOSS
08-18-2002, 05:46 PM
burbanite, if you are fouling plugs at idle, DO NOT go up in heat range. The hotter the plug, the harder you have to run it. Hot plugs are made for WOT not idle.