650/X-2 650SX NoobI Rebuild!!

[EuroSX4]

Hey guys,I'm new here.Decided to join since almost everyone on pwctoday didnt have a clue what they were talking about and always had a attitude.Anyways I picked up this 88 650sx last year and decided to strip it down and re do everything.Not going crazy on a restoration just painting it.Assembling together put in the pieces that are missing,swap some other new parts on and throw the engine back in it.Here are some pics of when I got the ski.

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Just some pics that were taken.I have jet to paint the ski.But more than likely my buddy will be painting it.Nothing crazy just plain white and maybe i'll throw some vinyl over that.Other than that the PJS head and motor were messed up.I still might have the PJS jug somewhere however I am not sure if it usable.The head was welded to the jug and came off in pieces.The jugs itself has some damage as well than can be seen in the pictures.I am not sure If I will be able to use it as it looks like someone ran this thing till it got red hot and seized.But we'll see I guess.I got 2 spare case and cranks with this ski and the motor that was in the ski at the time ran so I just might use that for the time being.I will have to check compression,leak down and pop off before I go any further.I do have a question.Since the carb that on the motor is a crappy BN 44 .Is it worth going to a 38mm SBN??Or running Dual SBN38's??Also if running dual which manifold to use??Will a manifold designed for sbn 44 work??I have a ocean pro dual manifold for snb44 brand new and will the SBN bolt on to the motor??

The motor has a stock exhaust but I do have a PJS header and a west coast water box and a jetpro intake manifold along with jet pro intake grate and a PJS ride plate.Suggestions are welcome.

 

[Kohldanielzimmer]

Use the sbn 44 manifold/carb. Too bad someone neglected that pjs cylinder. What type of damage does it have? Anything structural or mostly corrosion?

 

[orangefinger]

welcome abroad !!!

That Sx looks like it was badly neglected, with all the corrision make sure to blow out all thru hull water fittings, exhaust manifold etc.....
I would also agree to utilize 44mm & Intake, great set up

Please explain how they blocked the cases....the pics dont show just see 3/8 fittings

 

[Jpass]

I rebuilt the same ski a year ago. It's my back up ski for when the wife wants to hit the water. I went with a 46mm carb and intake on mine. In addition to what appears to be a Mariner pipe, dual stage reeds, high compression head, etc. Has a lot more snap to it now.

 

[EuroSX4]

Thanks for the kind words guys.I have been missing for a while.But I finally have some time so I will be getting back to the project.As I found out the PJS Jug is only 1mm bigger than the stock 650sx jug.Which is weird I thought they only made larger jugs like 700cc and 800cc,however the one in the pictures above is only 1mm over stock bore.However I confirmed it today. The piston bore is 77mm.I purchased a stock 650sx motor that needs a rebuild that was bored 1mm over stock.Did PJS change the stroke to achieve the 800cc or 700cc displacement??

I rebuilt the same ski a year ago. It's my back up ski for when the wife wants to hit the water. I went with a 46mm carb and intake on mine. In addition to what appears to be a Mariner pipe, dual stage reeds, high compression head, etc. Has a lot more snap to it now.

 

[EuroSX4]

So I got a quote today to get the jug bored over to 78mm per cylinder bore and have it honed and ready to go will be about 100 bucks which isnt bad.The piston kit will run me about another 200 and ill be looking for a sbn 44 carb more than likely new.Depending on whats available.That way id I do get bored i can always use dual 44 wit the manifold i got.

Still working on possibly getting the head decked/milled.I am not sure if its been milled already anyone have measurements of stock head and its thickness??

 

[Vumad]

Used SBN 44 carbs can be found for $75 in decent shape. Don't get carried away and spend too much money on an old ski. It only has so much resale value. Unless it's something amazing to you, go with the basics and save the extra money for upgrading to a different ski down the road. Just make this thing clean and reliable for the best value you can.

 

[EuroSX4]

Well i got the ski for cheap and it came with alot of parts.Not going too crazy on it.I picked up a freshly rebuilt carb for $110 already setup for my mods and it hasnt even had fuel through it since the rebuild,and it looks like new so i cant complain.Just gonna mod it and restore it a bit to make it reliable and still take a beating.Next on my list in a crank rebuild,extending the pjs rideplate another 2 inches,possibly stubby pump cone,and a bunch of free mods like dual cooling,premix and a few others.So far I havent really spent any money on the ski so far.Ive sold some parts that I wasnt able to use for my build and some stuff i had no use for and been using those funds to fund this project.I still have the oceanpro dual 44mm carb intakes maybe ill use that when i get bored of the single.


Plus these are just mods for the spare engine that I bought.I have another engine thats mostly complete in the ski that I wount be needing once this one is done.But I also have a few extra cases as well.

 

[dbattersby20]

Boring the jugs doesn't really give more power it is about the port work. Which I would think the ports are different than stock in that pjs set up. Where in nj are you?

 

[EuroSX4]

Northern NJ Near Clifton.I dont even know If i still have the PJS jug It wasnt useable the jug itself was deformed on one side.The cylinder walls were badly scored and pistons were toast.

Is it worth boring over another 1mm to get some more power out of this ski???Its already bored over to 77mm.

 

[dbattersby20]

I'm 30 minutes from Clifton. Boring doesn't really give more power.

 

[EuroSX4]

im sure borign will be give me even a small boost.Not looking for a crazy fast ski 46mph will do.Not looking to go crazy.Just would like some good power on the low end.

 

[EuroSX4]

So I got my mikuni carb and aftermarke flame arrestor anyone what manifold fits the mikuni 44 sbn???I have heard stock 650sx from 91 to 95 and other aftermarket ones??is this true anyone have one for sale??

 

[Wilke]

Any of the aftermarket 650 manifolds will work, all of them are setup for mikuni carbs: PJS, Westcoast, Team Butch, Mariner, etc. Looks like the pics in the original post already has a mikuni carb manifold, the BN and SBN both use the same manifolds

 

[EuroSX4]

Ok so Its been a while.Been busy with work and some other things.I picked up 78mm piston kit and will be sending out the jugs to get bored from the 77 to 78mm bore.Also looking for a intake manifold still.The engine in the pictures I still have but Is mostly stock.I picked up another engine that I am rebuilding.

 

[EuroSX4]

So I decided to put some more pictures of my progress and parts purchased.I purchased a 650sx engine that needs a rebuild for 25 bucks.It has HPT Sport engraved on the jug.I found their site but it seems they are no longer producing or performing work as my emails have gone unanswered.

Head I've stripped the paint of and will think about painting it but probably milling it.

Next is the SBN 44 I purchased freshly rebuilt.

With Flame arrestor

Finally new 78mm wiseco pistons which I will be sending out this week along with the jug to get bored.

That's it for now I also just a purchased a BCW Racing intake manifold for a SBN 46 which I'm sure wount make much of a difference even though all I'm running is a 44.