650/X-2 winter build 650/750

[N2 H2O]

I think that's supposed to be there. BL is a good seller and knows what he's talking about.

 

[Vumad]

I have Pro-X pistons. I kept hearing bad things about wiesco pistons so I chose not to get them. I have never had Weisco so I am not sure about them, but I am happy with my Pro-X.

 

[N2 H2O]

The wisecos have been great on my 650 for a lot of hard seasons. My neighbor, who owned the ski before me rebuilt it with wisecos in '05 and it still has good compression and runs great.

 

[dbattersby20]

from what i've read. the wisecos can be really nice they just take a little more maintenance. Because they expand differently (quicker( and require a different clearance between the cylinder walls. the ski needs to get warmed up before you start pulling the throttle. They are lighter and should have better power.
People also like the pro-x, but the price is right on the wiseco's right now

 

[N2 H2O]

Yeah I always warm the ski up really slowly because the wisecos are forged, not cast like other brands.

 

[dbattersby20]

i don't have a problem with doing warming it up... what would be the warm up process? as is i run it for a few minutes at the house then bring it over to the bay and ride around at less than half throttle for a few minutes...

 

[N2 H2O]

I just idle around for a few minutes and then run just up on plane for a few minutes and then just dont do any WOT runs right away. You can also feel how hot the water coming out of the bypass is to tell when the motor has warmed up.

 

[dbattersby20]

ive been looking around for operating temps... should an engine be around 190?

 

[Vumad]

If you warm it up at the house, it might not be warm when you get to your ride. Same is true if you leave it sitting for a while between rides. It needs to be warmed back up after any time spent sitting. Checking the pisser for hot water is a good suggestion.

 

[Austin]

My 650 had weiscos put in it the day it came out of the factory in 1990 and it still has never been rebuilt (21 years x 50 hours a year = a lot of hours on motor). I have never had any problems with weiscos great piston but did research and I put pro x's that I had lightened and trued put in to my new 750 because In watercrafts the cylinders stay cooler because of the water cooled so you cylinders don't expand but the piston will always be hot so when your motor runs so your pistons expand. That is why typicality on a ski your clearance from piston to cylinder is 6 to 7 thousandths, so there is room to expand. But forged pistons don't really expand so they don't run as tight and normal pistons. Like on a air cooled 2 stroke like a dirt bike or something like that you run piston clearance to cylinder is 2 to 3 thousandths because both the cylinder and piston expand.

 

[dbattersby20]

so now that my crank is pretty much out (still stuck to the top half of case for some reason) how can i check to make sure it's still good?

edit: and the pistons are art pistons which don't seem to have any markings on them except "k12"... im just trying to figure out where my bore is at

 

[Austin]

You want to check your bearings and see if they move back and forth. That is bad if they have play in them. YOu can always just measure your bore on the cylinder if you dont know what it is

 

[Vumad]

The crank rods will rock side-to-side very gently. There's a lot of leverage on them when the crank is out, but the pistons hold it in place when they are in the cylinder so that side to side rock is normal. However, the up/down movement is bad. The rod should be tight to the shaft if you pull the rod perpendicular to the shaft. If it moves in a perpendicular direction, your bearings are damaged. Also, pay attention to grinding or binding. A sign your bearings are going to fail soon. If in doubt, ask someone who knows to look at it or just replace it. A worn out crank can wipe out your whole new motor.

 

[dbattersby20]

There's no movement just a little side to side. The only thing that is wrong is some surface rust on the webs. And the fact that it is stuck in the top half of case. I'm going to make a jig to get it out though. I need to get the cylinders bored so I'll probably bring the crank with me to the machine shop and see what they think as well.

 

[dbattersby20]

I'm checking to see if i will be able to get away with a hone and re ring. So i bought a standard craftsman cylinder hone. Started of spinning at real low rpm to be cautious...thank god i did cause the stones hit a little piece sticking up on one of the intake ports and cracked the stone. A tiny, tiny chip came out on the sleeve but it didn't effect the cylinder wall surface at all so ill clean that up later hopefully. But i realized that this honer may not work because when i get down to the skirts the stones dont stay parallel to the sleeve. has anyone encountered this? Im thinking it doesn't really matter if i hone the very bottom of the cylinder skirt anyway. Now i need to order new stones though.

I got off enough material that i think it will clean up i just need to take measurements of the bore and pistons to make sure the clearances will be ok.

 

[Vumad]

If you are not sure what you are doing, find a local shop to do the work. Tell them you will pay them a few extra dollars to watch them do the job and explain what they are doing. A dealer will not do this, but there's a few small shops around me that would do such a thing. I often don't pay anyone to do work for me unless I don't ever plan on doing that work myself or unless they are willing to explain and show me the job. It's worth the money to get a lesson and know the job is done right. Tom21 for example let me do a few jobs at his shop. I gave him a few bucks and every once in a while he'd inspect my work and correct my errors. Finding a sweet gig like that would be pretty hard but finding someone who's going to let you watch them hone your part, especially if you throw them a tip, shouldn't be too hard.

 

[dbattersby20]

my brother actually knows how to do everything so i usually talk to him about it and have him look at stuff. he does a lot of work on cars so most of the work can translate to the skis, its just a little different. I know that if i had one of the $150 cylinder hones from lisle i could do the piston skirt its just the the $25 one pivots at the center of the stones...

 

[dbattersby20]

haven't made a lot of progress aside from just cleaning parts and prepping surfaces for paint or gasket surfaces. Im going to try products from por-15 for painting . I'm now just waiting on my order to come in. Im reusing the same crank and after honing the cylinder the piston/cylinder clearance is between .0048-.0052. Which is at the upper limit of clearance but should do for the season especially since im still running on pump gas (bought 26cc domes for an ada non girdled head). I still need electrics, and an intake manifold. For now im just going to run a single mikuni sbn44 rather than the dual cdk II. Should be cheaper than rebuilding the cdkII and getting flame arrestors for them. Plus i can sell them then to buy dual 44s. (starting point for jets? on the single 44 ) So if anyone has a manifold for sale that fits a small pin 750 with a 44mm let me know. I'm also looking for a piece of a 650 exhaust that i can cut like 3 inches out of to extend mine...

Also, i had to get a new pump because the impeller was scrapping on the old lining. I went to tap the new one for dual cooling and there is no extra bump to run an outlet through. So ill just tap the current hole for a bigger fitting and then split it after.

 

[dbattersby20]

still just waiting on parts. Sadly everything won't be in until friday or monday and i go back to school tomorrow afternoon. only two things came in. chain wrench from mcmaster and R&D intake from watcon, which was the last thing i ordered. Seems like people are just moving slow around the holidays.

 

[dbattersby20]

So I finally got a chance to stop home after my trip and unwrapped all the packages. Ebox is from Austin, looks good... big, but good (thanks). Bought a kawi flywheel lock from cold fusion to help get the coupler off, that way i can replace the crank seal. Ada head looks awesome. Question: how do i know when to replace the o-rings... and everything is installed dry, correct? I got a bunch of other small things as well like filters, piston rings, por-15 and what not.
I'm considering getting a factory pipe for a 750, looking at buying one from a guy on pwctoday in the next couple days. What will be the easiest way to route it to a water box in the front...stock position for a 650. will the pipe fit with a stock 650 tank? cause i also have a tank from a js300
Hopefully ill get a day off sometime and i can get the engine back together. then ill finish some of the smaller things and get the hull back together after school is over.
Some things ill need to do is get a flow control valve, a filter for the cooling lines. Tap the pump for a bigger 90 degree fitting since i don't have a bump for two fittings. I'm removing the fuel selector. Possibly getting a 500 gph pump since i have the wires coming out of the ebox anyway and then ill just run the pisser out where the fuel selector knob is.

Does anyone know where to get the rubber ring the goes around the driveshaft and into the tip of the impeller? Im not really sure it does anything except possibly keep water out of the spline area.