msx 140 03 relativley cheap performance mods??

[cupra20v.t]

i have recently bought my 1st msx 140, had a bit of a bad start with it as it nearly sunk. did a bit of inspection and found the support bearing was truely knackered and leaking water into the hull faster than i could get it in there with a hose pipe. ive bought a new bearing from polaris and had the shaft machined back to normal and its all installed and water tight.

im very happy with the ski but it does have a small misfire when im am full on the throttle. its not a constant misfre, i can just hear it every 3 seconds or so like the ski is bouncing off the water but its not.

anyway, im completley knew to the ski scene, i usually buy them and ride them. but im in the mood to make ski that little quicker or better at handling or basically anything, what can i do it guys, bear in mind im from the uk so some of the hi tech gismos you guys have in the states may not be available over here. im thinking of a different propeller but not sure what sort to go for, i want quicker acceleration but dont want to limit my top end speed. i would also like to do something to make the ski turn sharper at lower speeds.

any advice or tips will be great. thanks in advance.

[K447]

Welcome to the Hulk!
Which model year is your MSX 140?
What are the last four digits of the HIN number plate on the rear deck?

The 2003 models in particular had a fair number of important updates issued.

Unless you are certain everything has been updated, contact a Polaris dealer (even if you have to call the US), and confirm that all the outstanding Polaris Service Bulletins for you HIN have been completed.

Jay at AltanticPowerSports is often helpful to us Polaris Green Hulkers. His user name here is 4strokepolaristech

At the same time, you might ask him what is the likely cause of your miss at speed.

On some of the Ficht fuel injected models, the TPS (Throttle Position Sensor) itself could either become intermittent, or the electrical connections to the TPS would weaken from engine vibration.

You can unplug the TPS connector, and gently squeeze the female contacts a little tighter, then plug it back together.

[K447]

...anyway, I'm completely knew to the ski scene, I usually buy them and ride them. but I'm in the mood to make ski that little quicker or better at handling or basically anything,
what can i do it guys, bear in mind I'm from the UK so some of the hi tech gizmos you guys have in the states may not be available over here.
I'm thinking of a different propeller but not sure what sort to go for, I want quicker acceleration but don't want to limit my top end speed.
I would also like to do something to make the ski turn sharper at lower speeds...

You cannot easily mess with the engine power - the Ficht system is fairly rigid, and is matched to the stock engine air flow. No changes to exhaust or air intake.

That said, you can change the hull and jet pump.

If you have a 2003 MSX 140, the 2004 sponsons might improve the turning.
The 2004 MSX ride plate gives more top speed then the 2003.

An AAT can also give you a bit more performance.

Not sure if there is a better impeller than stock. Do check your impeller for clearance to the wear ring surrounding it. If the clearance is greater than about 0.010", then you are loosing a little performance there.

Some tuners fill in along the rear bottom edge of the hull where it rises from the water, to create a sharp 90 degree edge, reducing drag. On the MSX hull, you would probably need to do that at the forward step underneath...

Have a good read through the MSX/Matrix forum.

BTW, we love photos here!
Let us see what you have...

[ph2ocraft]

You cannot easily mess with the engine power - the Ficht system is fairly rigid, and is matched to the stock engine air flow. No changes to exhaust or air intake.

That said, you can change the hull and jet pump.

If you have a 2003 MSX 140, the 2004 sponsons might improve the turning. Same sponson, different color.
The 2004 MSX ride plate gives more top speed then the 2003.
You can also give the 03 plate an additional 4mm kick and have the sameplate as the 04. Most buy a new plate as it's simpler.

An AAT can also give you a bit more performance.
If you try the AAT route be sure to use their new angled unit.

Don't forget the 6 degree wedge, it's good for more speed as well.

Not sure if there is a better impeller than stock. Do check your impeller for clearance to the wear ring surrounding it. If the clearance is greater than about 0.010", then you are loosing a little performance there.
There are guys on the board and Dave at Impros who can modify the stock 7.0 impeller.

Some tuners fill in along the rear bottom edge of the hull where it rises from the water, to create a sharp 90 degree edge, reducing drag. On the MSX hull, you would probably need to do that at the forward step underneath...

Have a good read through the MSX/Matrix forum.

BTW, we love photos here!
Let us see what you have...

If you don't mind giving up just a hairs worth of acceleration and are looking for more RPM's, add another cylinder gasket (raises the ports). Randy at Watcon has the Gaskets in stock, he also has some index washers. I'd ask him if he thought they might help gain 40-50RPM's on the MSX140.
And don't forget the pictures!!!!

[cupra20v.t]

cheers for the replies guys. my ski is an o3 msx 140 the numbers on the back of the ski are 828303.

i did hear about the TPS coming loos or getting bad connections. where is this located? so i can check it out and clean/tighten it up.

when you say check the impeller clearance i tke it you mean the gap between the blades of the propellor and the case its surronded in?

what about different intake grates? are there more curvy ones out there that force or scoop more water into the propulsion system?

does the AAT give a noticeable difference?
thanks for the help so far. ill get some pictures for you lot later

[K447]

...my ski is an '03 MSX 140 the numbers on the back of the ski are ...8303.
That would be B303, so your unit was assembled Feb 2003, and is a 2003 model.

i did hear about the TPS coming loose or getting bad connections. where is this located? so i can check it out and clean/tighten it up.
Have a look at this thread.

when you say check the impeller clearance i take it you mean the gap between the blades of the impeller and the case its surrounded in?
Yes

what about different intake grates? are there more curvy ones out there that force or scoop more water into the propulsion system?
You can certainly install a more aggressive intake grate.
In general, they will improve hook-up in rough water, but cost 1-2mph in smooth water.
The R&D Aquavein intake grate, originally designed for the early 1990's Polaris SL650, is often recommended.

There is also a SL750 version of the Aquavein grate, and it will also work, but with more drag at speed.

There are other brand intake grates available, but I am not familiar with the important differences between them.

does the AAT give a noticeable difference?
thanks for the help so far. ill get some pictures for you lot later

AAT does seem to provide an improvement, but it is not going to have a huge effect overall.
I have one, but have not yet installed it.

If you have not done so already, download the 2003 Service Manual.

[RiverRat19405]

i have the r/d 750 intake grate brand new for sale if you want it send me a pm as i cant send pm to you for some reasion

[Andymunro]

Hi where can i find a workshop mannual for a polaris msx 140 2003 blk and red one as i need to re build my enhine and need all the settings before i can get out on it as i was ripped off when i bought it from ebay but dont worry they will be getting a knock soon enough if any one can help i would be greatfull many thanks Andy

[pirate33]

Oh Al LOL ... go back and look at what you said about the 03 to the 04 sponson, remember Havasu 300, ..Womack is it comming back yet?