DIY zen mods??
10-03-2008, 03:48 AM
#51
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RE: DIY zen mods??
Hi all
I assembled motor today and attempted bench run after a while of pulling on starter and playing with needle settings the only way it would run is to be heaps richer this does make sence to me but i'd like to find out what needle settings you run at for a modded motor
cheers craig
I assembled motor today and attempted bench run after a while of pulling on starter and playing with needle settings the only way it would run is to be heaps richer this does make sence to me but i'd like to find out what needle settings you run at for a modded motor
cheers craig
10-03-2008, 07:11 AM
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RE: DIY zen mods??
Does it run well and very consistent at that setting? If so then it is fine. But I guess you will have to get it in a hull in order to determine that.
Ryan
Ryan
10-04-2008, 05:18 PM
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RE: DIY zen mods??
I Have just been trying to get my zen to run smooth Here's the problem
In order for me to just get it started I have to have it semi choked (with my finger) then it will idle of for a while then Eventually die
then i'll start it again it'll do the same i'll give it a little throttle it sounds like it "bogs" then dies is this just tuning or do you think I have done something wrong while porting
. Before you ask the vent on tank is ok and spark plug is new and I am running cooling water through it while testing any help would be great thanks[
]
Cheers craig
In order for me to just get it started I have to have it semi choked (with my finger) then it will idle of for a while then Eventually die
then i'll start it again it'll do the same i'll give it a little throttle it sounds like it "bogs" then dies is this just tuning or do you think I have done something wrong while porting
. Before you ask the vent on tank is ok and spark plug is new and I am running cooling water through it while testing any help would be great thanks[]Cheers craig
10-04-2008, 06:33 PM
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RE: DIY zen mods??
On your carb there is a small hole in the bottom that makes the carb diaphram pump the fuel, it gets a pulse from the piston going up and down. If the hole isn't lined up through the gasket and intake manifold it won't pump fuel and you will have to semi-choke the carb to get it to draw fuel. I try to put the manifold and carb on before assembling the cylinder to the engine, that way you can check the alignment with some thin solder or a short drill bit.
10-04-2008, 07:00 PM
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RE: DIY zen mods??
instead of cuting out a perfect square couldnt you just drill a round hole ? would it have the same effect ?
im going to try the golfballing method , i dunno about window porting yet . damn ages ago on DDM i saw pics of TREVOR SIMPSON pistons that had window porting done to them and these pistons were for sale individually but they were 23cc pistons .
also on what side of piston do you do window porting ? is it the flywheel side or other side ?
im going to try the golfballing method , i dunno about window porting yet . damn ages ago on DDM i saw pics of TREVOR SIMPSON pistons that had window porting done to them and these pistons were for sale individually but they were 23cc pistons .
also on what side of piston do you do window porting ? is it the flywheel side or other side ?
10-04-2008, 07:19 PM
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RE: DIY zen mods??
ORIGINAL: munro1656
I Have just been trying to get my zen to run smooth Here's the problem
In order for me to just get it started I have to have it semi choked (with my finger) then it will idle of for a while then Eventually die
then i'll start it again it'll do the same i'll give it a little throttle it sounds like it "bogs" then dies is this just tuning or do you think I have done something wrong while porting. Before you ask the vent on tank is ok and spark plug is new and I am running cooling water through it while testing any help would be great thanks[]
Cheers craig
I Have just been trying to get my zen to run smooth Here's the problem
In order for me to just get it started I have to have it semi choked (with my finger) then it will idle of for a while then Eventually die
then i'll start it again it'll do the same i'll give it a little throttle it sounds like it "bogs" then dies is this just tuning or do you think I have done something wrong while porting
. Before you ask the vent on tank is ok and spark plug is new and I am running cooling water through it while testing any help would be great thanks[]Cheers craig
Hi Craig,
what happens if you give it a load of revs - or try to? Does it still die after bogging down?
Glenn
10-04-2008, 08:01 PM
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RE: DIY zen mods??
instead of cuting out a perfect square couldnt you just drill a round hole ? would it have the same effect ?
im going to try the golfballing method , i dunno about window porting yet . damn ages ago on DDM i saw pics of TREVOR SIMPSON pistons that had window porting done to them and these pistons were for sale individually but they were 23cc pistons .
also on what side of piston do you do window porting ? is it the flywheel side or other side ?
im going to try the golfballing method , i dunno about window porting yet . damn ages ago on DDM i saw pics of TREVOR SIMPSON pistons that had window porting done to them and these pistons were for sale individually but they were 23cc pistons .
also on what side of piston do you do window porting ? is it the flywheel side or other side ?
10-04-2008, 08:03 PM
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RE: DIY zen mods??
Hi Glenn
yeah it won't rev big pritty much at all, I was just about to go and take carby and manifold off again to be sure the pulse port is lined up as mike said
cheers craig
I did a little golfballing on my piston I just liked the ideathe theroy behind it works I don't think it can hurt only benefit
yeah it won't rev big pritty much at all, I was just about to go and take carby and manifold off again to be sure the pulse port is lined up as mike said
cheers craig
im going to try the golfballing method
10-04-2008, 08:39 PM
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RE: DIY zen mods??
well I think I found the problem gasket was covering pulse port (thanks for the tip mike) now it's time for a little tuning then back into boat to give it some load testing
10-04-2008, 09:23 PM
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RE: DIY zen mods??
ORIGINAL: Ron Olson
One of the cheapest hop-ups is adding zero-drag seals. They're around $15.00 and will add 200-500 more RPM.
One of the cheapest hop-ups is adding zero-drag seals. They're around $15.00 and will add 200-500 more RPM.
10-04-2008, 09:52 PM
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RE: DIY zen mods??
ORIGINAL: munro1656
well I think I found the problem gasket was covering pulse port (thanks for the tip mike) now it's time for a little tuning then back into boat to give it some load testing
well I think I found the problem gasket was covering pulse port (thanks for the tip mike) now it's time for a little tuning then back into boat to give it some load testing
Craig, let us know how it works out for you. I still have a lot of work ahead of me.
Ryan
10-04-2008, 10:00 PM
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RE: DIY zen mods??
where are you guys buying your zero drag seals
cheers craig
10-04-2008, 10:28 PM
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RE: DIY zen mods??
Thanks mike
I seem to have it running ok now
I have always had a cooper pipe on it when it was stock and I't didn't seem to rev hard or "get on pipe" like other stock zens i've heard you think the pipe is holding me back at all
cheers craig
I seem to have it running ok now
I have always had a cooper pipe on it when it was stock and I't didn't seem to rev hard or "get on pipe" like other stock zens i've heard you think the pipe is holding me back at all
cheers craig
10-05-2008, 04:19 AM
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RE: DIY zen mods??
ORIGINAL: munro1656
I have this one
I was just thinking with the baffle and offset exit pipe it may reduce flow
I have this one
I was just thinking with the baffle and offset exit pipe it may reduce flow
Glad you got the motor running nearly right now Craig, what length of manifold do you have? You want to be aiming at somewhere near to 350mm from port to the largest part of the divergent cone, then shorten from there to get the best power for your boat.
I have not run one, but have only heard good things about cooper pipes, I know of two boats that use the same (or pipes that look the same) as yours and they go very well.
Glenn
10-05-2008, 05:35 AM
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RE: DIY zen mods??
As Glenn said, that pipe works good. I use Cooper offset mufflers with no loss in power. It needs a 90* or 100* header to work best. What header are you running?
10-05-2008, 06:58 PM
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RE: DIY zen mods??
This is the one I have been using in order to keep pipe inside boat the mearsurement is 340mm from manifold to largest part
10-05-2008, 07:50 PM
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RE: DIY zen mods??
ORIGINAL: munro1656
This is the one I have been using in order to keep pipe inside boat the mearsurement is 340mm from manifold to largest part
This is the one I have been using in order to keep pipe inside boat the mearsurement is 340mm from manifold to largest part
Only experimentation will prove it all out for you.
It is a good start point, if you do need to go shorter though it is goin to be a pain in the a*se, you might need a 90 or 110 manifold and some bodywork redone on your boat.
It'll all be worth it though.
Glenn
PS - I am not a fan of aluminium headers. In my experience they are too soft. Go stainless.
This is my opinion only. Based on experience.
10-05-2008, 10:10 PM
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RE: DIY zen mods??
I am not a fan of aluminium headers. In my experience they are too soft
I could not agree with you more!! When I pulled motor out that header has been distorted from heat and is now R.S. I have put on order with danny from sonicracing one of his hot pipes and a new dual pickup rudder so between the two pipes I should be able to get max power and should get this motor to the edge of distruction[>:] thats why we build 'em isn't it
cheers craig