Advice on what to install first (Kawy 650sx upgrades)
A. Saganich
I've been lurking reading posts, emailing people and looking at websites for
a while to get an idea what to upgrade on my '89 Kawy 650sx. It runs great
but I want a little more punch. I've sort of narrowed it down to the
following:
Rule 500 bilge pump (Was it a 550? I can't remember, about $90)
Either a west coast or coffman exhaust system. The seem to be almost
identically priced (about $275).
Here comes the first question. What if any benefit do I get to replacing
the exhaust manifold (other then lightening my wallet by $120!).
I've also looked at replacing my carbs a Mikuni 44mm seems to run about
$160. Do I need two? What about intake manifolds? Will the new carb's
fit on my stock manifold or do I need to replace it? What about replacing
the choke with a primer kit? I understand the Mikuni 44 would take such a
thing.
I've heard of lots of other stuff, waterbox(es) replacement air filter
things etc.
Any thoughts?
Thanks tons!
Al
PS. Please reply to my email address as well I don't get to this group as
often as I like!
--
A. Saganich
Al.Sa...@Digital.com
-Let no good deed go unpunished!
Jettski
ask. It will need a new manifold to go with it. The Coffman's is a great pipe
for that ski as is a Factory Pipe. Go ahead and get the manifold, it will help
some. Keep the stock waterbox, but since I think yours is a rear exhaust, a
Jetcraft Turbomuff with a lot of water in it would be good for some power if you
have the money for it while keeping a nice tone, not tinny. Do you have a
stainless impeller yet? If not, that would be the first thing to replace along
with a scoop grate.
Darin
Foster4300
with interchangeable domes like I have.
JMikos
>identically priced (about $275).
>
I have a WestCoast on my X-2, simply because I got it super cheap from my uncle
for about 75 bucks, and i am very happy with it. He took it off his X-2 to put
on a Coffman. There are two resons the Coffman is better. Number one, the
headpipe can be tuned. If you ever do any porting/compression changes, teh
head pipe can be shortened the tiniest bit equally on either side, and you can
actually gain a few more horses this way. You can't do this with the
Westcoast. I would highly recommend staying away from the Factory pipe. In my
opinion they are complete crap. My friend Craig has had to weld his on his '96
Super Jet twice now, because they didn't bother to engineer any pipe supports,
and it bangs against the inside of the hull upon hard impact. Furthermore, I
have heard of numerous other people having problems with them cracking at the
welds. The Factory pipe is the equivalent of the Ford in my opinion.
>Here comes the first question. What if any benefit do I get to replacing
>the exhaust manifold (other then lightening my wallet by $120!).
>
Actually, the aftermarket manifolds do help quite a bit, because of the deeper
exhaust diverter. Again though, you won't see a big HP increase unless you
port your motor. I wouldn't bother until you start doing some other mods
first.
With all this about porting, it should be one of the last things you do. I
have tacked on 10 mph on to my X-2 with just bolt ons, and I haven't sacrificed
any reliability. If and when you ever decide to have any porting/head work
done, I would highly recommend sending it down to Group K - actually, Aqua
Sports is doing all their old Kawi work now.
>I've also looked at replacing my carbs a Mikuni 44mm seems to run about
>$160. Do I need two? What about intake manifolds? Will the new carb's
>fit on my stock manifold or do I need to replace it? What about replacing
>the choke with a primer kit? I understand the Mikuni 44 would take such a
>thing.
Group K recommends the 42 Keihins, and i am EXTREMELY happy with mine. A carb
is the first thing you should do on that thing. The 28 mm Keihins were way to
small for even the stock motor. That is why Kawi switched to the 38mm in '91.
If you can get a hold of a stock 38mm manifold from a '91 or later 650 boat, it
can be bored to acomodate the 42. A primer is a must no matter what carb you
use. Dual carbs are uneccessary.
>I've heard of lots of other stuff, waterbox(es) replacement air filter
>things etc.
I didn't see a big HP gain with my Westcoast waterbox, but it sure as hell
sounds cool.
>Any thoughts?
First and foremost, get a Skat Trak variable pitch impeller, the primer kit
(you can swap it over to the 42mm Keihin when you get one) an air filter (Ocean
Pro Vortex is good if they are still around) and a Westcoast scoop grate. DO
NOT get an R&D top loader grate. They suck because they slow the boat down a
lot. If you can still find a Jet Dynamics ride plate/top loader combo, that is
the ultimate way to go. But you will spend some bucks. Keep in mind a top
loader will slow the boat down a bit, so it would be good to increase the HP
first.....
Hope I haven't rambled on too much and that this was useful....
-Joe
DanJB2
skat trak, 42 keihn carb(will use the stock intake with some modification),
milled stock head(160psi), R&D toploader, mild port job. thing was the
quickest holeshot I have had. faster than limited fx1 and 750
Erik
old that you may well have a fairly worn crank or worn top end and you could be
heading for disaster by modifying your ski for more HP. If it is you should
probably have the crank rebuilt/welded and rebuild the top end (bore/hone
cylinder, new piston assemblies). Assuming your crank and top end are in good
shape, I would recommend proceeding in the order as follows: replace (crap)
aluminum impeller with a Skat 15 or 15.5 or Solas "A" or "I"; Westcoast
grate/plate or JetDynamics if you can afford it; Coffman's 650 exhaust (much
better than Westcoast); must replace carb/intake manifold at same time as
exhaust - single 42mm CDKII Keihin or 44mm SBN Mikuni; mill/recut stock head or
aftermarket for higher CR (92octane compatible). Accessories to add would be an
800gph (round body) Rule pump ($30 - forget the $90kit sheesh!); primer is a
must; new handlebar and grips. Forget about dual carbs or a waterbox swap.
Porting is an option if you don't mind spending the cash.
A. Saganich wrote:
> Folks,
>
> I've been lurking reading posts, emailing people and looking at websites for
> a while to get an idea what to upgrade on my '89 Kawy 650sx. It runs great
> but I want a little more punch. I've sort of narrowed it down to the
> following:
>
> Rule 500 bilge pump (Was it a 550? I can't remember, about $90)
>
> Either a west coast or coffman exhaust system. The seem to be almost
> identically priced (about $275).
>
> Here comes the first question. What if any benefit do I get to replacing
> the exhaust manifold (other then lightening my wallet by $120!).
>
> I've also looked at replacing my carbs a Mikuni 44mm seems to run about
> $160. Do I need two? What about intake manifolds? Will the new carb's
> fit on my stock manifold or do I need to replace it? What about replacing
> the choke with a primer kit? I understand the Mikuni 44 would take such a
> thing.
>
> I've heard of lots of other stuff, waterbox(es) replacement air filter
> things etc.
>
Factory Pipe
> My friend Craig has had to weld his on his '96 Super Jet twice now
Please let your friend know we have a lifetime warranty on our systems (unlike any
other company) and will gladly replace his chamber with a brand new one.
> it bangs against the inside of the hull upon hard impact
The chamber is fairly short and light and is supported at the headpipe coupler and
the waterbox. We have never used any chamber brackets on the 650 pipes and have not
heard of this being a problem. Have your friend call and we'll try and sort out why
this is happening.
> have heard of numerous other people having problems with them cracking at the
> welds.
Being a stamped and welded product we do expect to have a certain amount of
failures. This is why we offer the lifetime warranty as mentioned above.
> The Factory pipe is the equivalent of the Ford in my opinion.
I'm sorry you feel that way, what can we do to change your mind?
Robert
--
The Factory Crew
"Horsepower is a Beautiful Thing"
http://www.factorypipe.com
Nathan Barnett
If Factory Pipe is a Ford, then it is a '69 Boss 429. I haven't had any
problems with mine, and I wouldn't run anything else on my Super Jets.
Nathan Barnett
JMikos
>years
>old that you may well have a fairly worn crank or worn top end and you could
>be
>heading for disaster by modifying your ski for more HP. If it is you should
>probably have the crank rebuilt/welded and rebuild the top end (bore/hone
>cylinder, new piston assemblies). Assuming your crank and top end are in
>good
>shape, I would recommend proceeding in the order as follows: replace (crap)
>aluminum impeller with a Skat 15 or 15.5 or Solas "A" or "I"; Westcoast
>grate/plate or JetDynamics if you can afford it; Coffman's 650 exhaust (much
>better than Westcoast); must replace carb/intake manifold at same time as
>exhaust - single 42mm CDKII Keihin or 44mm SBN Mikuni; mill/recut stock head
>or
>aftermarket for higher CR (92octane compatible). Accessories to add would be
>an
>800gph (round body) Rule pump ($30 - forget the $90kit sheesh!); primer is a
>must; new handlebar and grips. Forget about dual carbs or a waterbox swap.
>Porting is an option if you don't mind spending the cash.
>
I think that's exactly what I said in the last post I made........Just in a
different way.
'Cept I forgot about the tired motor part. Thanks for pointing that out.
One fallacy here though - Don't bother with 15.5 - go to a 9/17 variable pitch.
Skat Trak makes 'em for the 650's You're wasting your time with a straight
pitch prop.
-Joe
MR-HPT
and refrain from posting bogus data. I built many engines using Coffmen West Coast
and Factory Pipe engines. Each product perform beautifully in it's designed power
band characteristic's. George HPT Sport USA http://www.hpt-sport.com
JMikos wrote:
> > Either a west coast or coffman exhaust system. The seem to be almost
> >identically priced (about $275).
> >
>
> I have a WestCoast on my X-2, simply because I got it super cheap from my uncle
> for about 75 bucks, and i am very happy with it. He took it off his X-2 to put
> on a Coffman. There are two resons the Coffman is better. Number one, the
> headpipe can be tuned. If you ever do any porting/compression changes, teh
> head pipe can be shortened the tiniest bit equally on either side, and you can
> actually gain a few more horses this way. You can't do this with the
> Westcoast. I would highly recommend staying away from the Factory pipe. In my
> opinion they are complete crap. My friend Craig has had to weld his on his '96
> Super Jet twice now, because they didn't bother to engineer any pipe supports,
> and it bangs against the inside of the hull upon hard impact. Furthermore, I
> have heard of numerous other people having problems with them cracking at the
> welds. The Factory pipe is the equivalent of the Ford in my opinion.
>
> >Here comes the first question. What if any benefit do I get to replacing
> >the exhaust manifold (other then lightening my wallet by $120!).
> >
> Actually, the aftermarket manifolds do help quite a bit, because of the deeper
> exhaust diverter. Again though, you won't see a big HP increase unless you
> port your motor. I wouldn't bother until you start doing some other mods
> first.
>
> With all this about porting, it should be one of the last things you do. I
> have tacked on 10 mph on to my X-2 with just bolt ons, and I haven't sacrificed
> any reliability. If and when you ever decide to have any porting/head work
> done, I would highly recommend sending it down to Group K - actually, Aqua
> Sports is doing all their old Kawi work now.
>
>
> >I've also looked at replacing my carbs a Mikuni 44mm seems to run about
> >$160. Do I need two? What about intake manifolds? Will the new carb's
> >fit on my stock manifold or do I need to replace it? What about replacing
> >the choke with a primer kit? I understand the Mikuni 44 would take such a
> >thing.
>
> Group K recommends the 42 Keihins, and i am EXTREMELY happy with mine. A carb
> is the first thing you should do on that thing. The 28 mm Keihins were way to
> small for even the stock motor. That is why Kawi switched to the 38mm in '91.
> If you can get a hold of a stock 38mm manifold from a '91 or later 650 boat, it
> can be bored to acomodate the 42. A primer is a must no matter what carb you
> use. Dual carbs are uneccessary.
>
> >I've heard of lots of other stuff, waterbox(es) replacement air filter
> >things etc.
>
JMikos
>apologize
>and refrain from posting bogus data. I built many engines using Coffmen West
>Coast
>and Factory Pipe engines. Each product perform beautifully in it's designed
>power
>band characteristic's. George HPT Sport USA http://www.hpt-sport.com
>
Off target? I never questioned the performance gains from the pipe - I merely
stated that I feel that the structural integrity, and engineering that goes
into the pipes is poor. I think that there is enough evidence to back this up,
considering the replies that people have posted on this newsgroup - there have
been at least two other people here that said they have also had problems with
their pipes cracking. Factory Pipe may very well indeed have a good warranty
program, but a well manufactured pipe will not fail in the first place. My
intention was not to flame Factory in any way - I'm sorry if I came off with
harsh criticism. But I simply feel that there are pipes out there that are
much better, and my intention was to steer someone clear of going through the
headache of having to deal with a part that has failed.
-Joe