[Lars_Gryyta]

Hey, i have a 600 with a compression of 120psi cold and 105-110 when hot.(my psi thingy could be off too)
It bogs down completely if i give it more than 3/4 off the throttle. It runs great otherwise and starts at the second pull.

What gives me the bog? Prob the gas flow through the main jet?
(crosshatching on the cylinders looks nearly perfect)

 

[Lars_Gryyta]

exhaust side looks a bit worse

 

[kccats]

Welcome
So why did you pull it apart?

 

[Lars_Gryyta]

Welcome
So why did you pull it apart?

1.because it has bad compression.(which i already knew)
2.because some suckers mixed diesel and gas in one jerry can.(clean fuel system and flush the carbs)
4 Then i realised one engine mounting plate got damaged.
5 because i had torn apart basically the whole sled i decided to look how the engine looks inside.(everything looks pretty good exept the pistons)

The clutches got a rebuild too.

Only thing i can see is left are the pistons or not getting fuel...

It accelerates further if you are easy on the throttle, fullthrottle it bogs down after 1/2 second


Got the sled for pretty cheap when i was 14, so i wasnt too educated about sleds and wanted somethig to learn on.

 

[Lars_Gryyta]

The sled is put together completely, so i can test carb stuff n so easily.
And ill fill it up completely tomorrow, suspecting the fuel line could float a bit and suck air.

 

[Coolhand]

You really should replace that one carb boot, along with checking the reeds for any issues.

 

[Lars_Gryyta]

You really should replace that one carb boot, along with checking the reeds for any issues.

Which one should get replaced? the cracked or the glued one😅I know, i have already ordered them. The reeds look fine in my eyes, no damages or cracks/loose ones.

 

[Lars_Gryyta]

Quick update, the sled now runs perfectly with gas in it. UNTIL I give it full throttle, then it bogs down all the way with a a bit brighter sound than when running usual. If i just give it 1/2 or 3/4 throttle i runs absolutely great and picks the skis right up.

If i stop it has a high idle for 1-4 seconds depending on how hard i rode the minute before. Is that okay or is it a problem? Boots leaking a bit of air or what?


What could be the issue?
Main jets plugged after running diesel/old gummed up fuel?

 

[kccats]

Hey what happens if you hit the choke when it bogs?

 

[Lars_Gryyta]

Hey what happens if you hit the choke when it bogs?

Didnt get to drive it today, but i noticed the fittings from the carb vent lines were broken off. That could very well be the problem, right?

 

[kccats]

You have removed all the jets including the Pilot (up the tube) and the air screw and cleaned all the passages right?

 

[Lars_Gryyta]

I was in a hurry getting it running again, so i just flushed it with carb cleaner and cleaned the main jet and pilot. Nothing more in the carbs.

The thing is that i get it to 7800rpm exactly under full but if i give it full throttle it bogs down, not completely, just to going like 40kmh. If i let off the throttle a little bit it accelerates again. Combined with the broken off carb vent/pressure lines I found it adds up perfectly to one guy back in 2004 with the exact same description on his problem (2003 xc 600 ves) bogging down. His problem was the vent line fittin broken off. (same thing on mine)

Could be the jets, but it comes so abrupt and continously, so I almost wouldnt think its the jets.
The idle thingy could posdibly be the pilot jet clogged again by some remains or so.

 

[kccats]

Had this on my Drag sled

Seriously you are either running out of fuel hence the choke flip question!
Or your main jet is just too big and the choke wont do a thing!

 

[Lars_Gryyta]

Had this on my Drag sled

Seriously you are either running out of fuel hence the choke flip question!
Or your main jet is just too big and the choke wont do a thing!

The choke works very well to be honest, there is no cold start without choke, but i just cant test full throttle because its pitch black when im home, nothing worse than crashing or getting stranded at night. But its so aprubt that i wouldnt expect that problem with running out of fuel and it worked a month ago, so i wouldnt expect it changed the jets on its own^^
Gonna look over the jets for the idle and get some new fittings for the vents.

 

[kccats]

What I am saying is when at wide open if it is bogging then flip the choke and see what happens!

 

[Lars_Gryyta]

What I am saying is when at wide open if it is bogging then flip the choke and see what happens!

Gon do that, i checked everything on the carbs and got the plugs... will test it today in the dark😑

 

[kccats]

If it goes better you are lean if it dies out you are too rich!

 

[Lars_Gryyta]

It was the vent hoses...the problem did go away, if i disconnected them it came back.
I checked the jets and the pilot was plugged again plus the main is a 410 instead of 310, the spark plugs look fine though. At least i know why it takes some real amount of fuel at full throttle.

 

[Coolhand]

What year and model exactly? Check Polaris Browse for the main jets plus all depends on of course sea levels and air temps for the jets. Should have a sticker underneath on the hood or airbox usually.

 

[kccats]

Sounds like someone has really messed with it!
OK well the choke would have flooded it out and killed it!