The rods shouldn't have any slap 'SIDE TO SIDE' and shouldn't bind grind or anything else that doesn't seem normal.... don't let anything drop in there

 

How much money in parts would it be to rebuild the bottom?

Bearings and seals (I guess 4 main bearings? )

Wondering if its just easier to do it now if its not unrealistically priced

 

Anyone has a guesstimate?

 

So while I wait for the pistons in the mail, I decided to try something new with the carburators.

I took one of them apart and removed gaskets / needle / slide and jets...

Then boiled it in lemon juice/water mix.

I like the results.

Before




After

 

Another update!

I got my parcel with the pistons/gaskets for the top end.

Will se if I have time to do this on the weekend.

Will try to at least clean the second carb.

 

Piston wash...

1994 EXT 580 EFI ( that got converted to CARB )



Your help and advice is appreciated. (never done a snowmobile rebuild, just a few top end on dirt bikes)

You are running too RICH due to the look of your piston crown.


Quote: DynamoJoe
Remember:
***Carbon only sticks to a HOT piston***
We do jetting so that the dome is covered in that light grey/brown color... covered in carbon.
For correct piston wash the piston must be nearly completely covered in carbon.
The 4 little fingernail size ''White'' areas are where the carbon is Washed off due to piston cooling being the greatest in that area.
If there were no fingernail size areas and the top of the piston was total covered in carbon, the engine would burn down from being too lean.
The bigger the fingenail ''white'' areas get, the more RICH the mixture is.
Fuel is great to keep the piston cool so there is more carbon ''washed'' away at the transfer ports.

 

I'm rebuilding a 580 also
one thing on the carbs look up a google search for "baking soda" blaster for carbs, i bought ebay pistons 100.00, gasket set 55.00, for bearings the crank bearings are spendy , its cheeper to send the crank to northern crank repair and get it trued also, and buy yamabond crank sealant , look for cracks in the y pipe and boil the clutch also, , i also electrolysis cleaning my pipe and y to repaint them, all the rust come off them using a tub of water and a little baking soda, and a battery charger , with two metals in the water , i found it on youtube ,works good

 

Here is a long awaited update to this thread, I actually let the snowmobile sit all winter apart (went back to university and had no time to do much)

So my timing sucks, but with my teachers on strike now, I had time last weekend to put the top end back together and install the engine back in.

:wacko:












Hope this oil pump arm looks properly installed (slack looks quite big when at rest-but fully open when throttle is wide open)



I actually got it started for a few seconds, but it revs up to the moon and I had to shut it down quick- the intake rubber boots seem fine (I inspected them really well when they were off).

When I pull the chokes (brand new plungers an cables were installed [were seized up when I took it all apart]) the engine RPM comes down to a normal low idle, overly rich, bogs when throttled with the chokes on)

So i'm thinking Air leak?
Or did I messed up cleaning the carbs and its now somehow doing that? (I did not touch the throttle screws at all, still at the same rusted spot as when I took it all apart)
Or maybe there is something else im not thinking of?

PuzzledI dunno

Can someone tell me/show me (picture) the slide of the carb on a 580 at rest? how much is it open for idle?

 

Yep,air leak OR I'm thinking your carb slides are not all the way down. Make sure they are installed right and Iv'e seen the needles hold them up if not in the needle jet right. Do you have play in the throttle,maybe the cables are set to tight(short) and holding them up.

 

Wow! That rust remover did an awesome job. It's hard to read the bottle "Evapo Rust"? I'm doing some work to my sled this off season. I'll have to get some.


I agree with the above poster on the slides. Check the slide adjustment screws on both carbs. I'm betting their turned all the way in.

 

The evaporust did ok (better than I thought-on the bolts and bits), you just soke it in for 24h or more. After that I still wired brushed to shine it up, so don't think it comes out that way

I actually checked the idle screws and all the carbs and still getting the high rpm starts.

If I remove the idle screws completely, and disconnect the throttle cables completely, are the slides in the carbs going to block the carb passage fully? Is that what's suppose to happen!?

 

The slides should drop down to "nearly closed".
If you can see more than just the slide cutaway (into the carb throat) then they are likely hanging up somewhere and that will cause your high idle.

 

Didn't have any time to work on it, but today I went in to take off the carbs and see how far the slides would go down in the carbs if I were to discionnect the throttle cable all together.

I didn't even get to put it back together and think I found the cause of the high idle - 99% sure it is the reason.

Unfortunately, I was called back to work and had to take off and no time to reinstall and test.

So.... The reason for the high idle would seem to be in the partialy opened up slides in the carbs (cables not stuck- not are they cought up on anythin)- the cables have two bulbs on the end and I hooked the slides on the 2nd one from the short end- hence pulling the slides up 1/4 inch higher than the bottom notch on the cable would.

 

Here is what I'm talking about


Slide at rest on the upper cable stop


Slide at rest on the lower cable stop (the fix to high rpm)

 

Well..... After adjusting the throttle cable and playing around with the slides, here it is.



http://vidmg.photobucket.com/albums...s/v700/DRZDemon/zr580 2014/F8234C42-254F-476E-9774-BD630D0D76E8_zpsmnvj3voc.mp4

 

I wanted to make sure that the new choke cables and plungers were sealing off the choke passage completely when closed off- so not to suck in air/fuel when not needed.

So I measured the dept of the plunger cavity and came up with a measurement of 1-1/16"


Then I measured the choke assembly from the bottom of the plunger to the top of threads (with choke off) and adjusted the lock nuts to make this measurement 1/8" longer than the cavity dept= 1-3/16".


Just to verify I sprayed carb cleaner in the choke passage with the plunger closed- it came back flying in my face and nothing made it through past the plunger. Cat happy

 

Thanks for everyone's input, got to test ride the sled this weekend!
Did a few warm up cycles and made sure the radiators are warming up- topped up coolant (with the nose of the sled way up).
Then went out the lake to see what's what....

Here it is:Cat happy

 

Nice work! Looks like it ran well.

 

I could never figure out how to adjust my new choke cables and plungers in my 580. Great idea!