Hey everybody! My names Mayday and I am building a 550sx(kind of) for my daughter to ride next summer. We have two skis one 90sx pp motor and one 83js pp motor that we are pullin parts from. I am hoping to keep my costs relatively low but understand the $$$ involved with building one of these prehistoric beasts. Hoping to end up with a nice entry level ski to have fun with for a few years. Will try to post pics as we go.
300/440/550 First time 550
- Thread starter MAYDAY
- Start date
Polish jet pilot
4aces4aces4aces4aces4aces
- Location
- Warsaw, Poland
Good luck! Personally I would go for the reed motor as pp motors in these skis (top ends) last 1-2 seasons max! The cylinders get ovalized quickly and skis loose compression and do not want to start...seen it on many many 550...
Yea I was worried about the reliability factor but i am really focusing more on the experience of a teardown and build up. If we get a few seasons out of it that will be more than satisfying for me. I am currently looking for a realistically priced rnsj which will leave my 650snsj for her to move into. Thanks for the advice tho i appreciate all viewpoints !!! Mayday.
N2 H2O
Previously Tbone550
- Location
- Charlotte, NC
If your going to stick with the pp motor, at least switch out your bn carb for a sbn. It made a big difference in starting and reliability on my 90 550. I've gotten 5 years out of my 90 550 and it's still running strong with great compression. Also, go ahead and rip out the old rubber mats. They will eventually start to peel off and I never liked them in the first place. Go ahead and re-do it with hydroturf. It's really nice on mine.
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I will see if i can find a sbn carb hopefully not too $$$. Funny you should mention the turf I just finished a conversation with my wife and daughter where they told me they wanted to leave the turf and deal with more relevant improvements first! I will definitely be changing that stuff out...eventually. By the way TBone what is a "Viper 7000" ? Mayday.
N2 H2O
Previously Tbone550
- Location
- Charlotte, NC
Most finger throttles are 10mm. The pre-86 cables require an adapter. The 90 stock throttle cable is a 10mm. A viper 7000 is a pjs motor that came in pjs laserjets. They're a ported reed 550 with the ebox mounted to the front of the cylinder and slightly larger cases. It also has a high compression head with dual modified cdkII's. They came stock this way.
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N2 H2O
Previously Tbone550
- Location
- Charlotte, NC
I like the umi ones. They have almost no play in them and are very comfortable. The cast ones have a lot of play in them. The umi ones are $30 more, though, so is it worth it to you?
Polish jet pilot
4aces4aces4aces4aces4aces
- Location
- Warsaw, Poland
PJS throttles are v.nice. I rode a few seasons with nornal BN carb (bored top and f/a installed - worked just fine - just make a nice routing from tank to carb and from carb bak to tank wit restrictor - install a primer instead of choke - you will gain a bit of power and ski should start nicely. Definitely look at your starter and cables!! The starter must be perfect otherwise it is going to play you.. good luck!
Polish jet pilot
4aces4aces4aces4aces4aces
- Location
- Warsaw, Poland
You cant really be looking at anything...the starter in 550 is integrated with the bendix - if you attach positive and negative wires to it it should work. Make sure it is watertight (use silicone on the orings)
Well I finally got my crankcase torn apart today and was pleasantly surprised!!! Not anywhaere near as bad as I thought it was gonna be. A bunch of dirt and grime on the stator and even in bottom of crankcase but I think once its all cleaned up and re sealed it should be good. Shaft itself is very tight but one of the ball bearings sounds as if it needs greased, any suggestions? Also cracked open my Ebox and found it looks pristine inside but a few of the plastic connectors that screw thru the box are broken. Not sure what to do about that? Will post some more pics later when i can get to it. Mayday.
Polish jet pilot
4aces4aces4aces4aces4aces
- Location
- Warsaw, Poland
You need to have your crank checked. A noisy bearing is something that indicates that the motor did not have lubrication in a long time and the bearing might be out of spec. I strongly suggest you relly look into the crank issue as this is the backbone of any 2 stroke motor really..
- Location
- Minnesota
Almost sounds like its gonna be more than its worth to try and fix up an old 550 motor. could always do a 650 motor swap.
nice silver motor for like 400 bones right now over on pwctoday which is a killer deal.
many build threads for the swap on pwctoday.com
nice silver motor for like 400 bones right now over on pwctoday which is a killer deal.
many build threads for the swap on pwctoday.com
N2 H2O
Previously Tbone550
- Location
- Charlotte, NC
650 swaps are definitely a lot of fun. way more power and reliability than you could ever reasonably get on a 550, especially a pp. You can check out mine in my sig. If you do decide to fix the 550 up, make sure to use a reputable company if you need to rebuild or buy a new crank. Art Gomez at Jetworks is a great guy to deal with and knows his stuff. I would highly suggest him.
- Location
- Minnesota
Imho you might spend more than its worth to rebuild the motor. so a swap for a 650 or 550 reed motor seems the most logical to me.
you guys are ont he money! I really thought i had a good crank and this was going to be a simple tear down anr rebuild but it isw looking like I will be better off to part what i habe and go get another square. O well lessons learned! will keep you posted on what i decide. Mayday.