'99 big boss

Started with replacing battery, so far so good...

Changed oil, 0W-40 synthetic, new filter, a freind stopped by, put oil in - because of ditraction, forgot to put the plug in... noticed almost right away, fortunately!

Rebuilt the carb support (broken on both sides), all good 'til now.

I had some new gas line, changed the main line from the tank, with a new gas filter. Now the shut off leaks... grrr!

Ok, put all the cowling back on, try to start, nuthin' ?

Pulled it all apart again, checked lines, all good - bike starts - why, I dunno?

White weird smelling smoke out the tail pipe? Oh-Oh! Turn it off immediatly?

Recheck everything... all seems okay... check the oil, almost no oil?

Now bike does not start, gas leaking from an exhaust joint, behind the muffler... not good!

It's getting dark, it's cold...

Pull the plug, compression is 60 lbs. Don't think that's high enough?

What is the correct comp. for the 500 cc motor?

I am a driveway mech., many tools, some skill... What happened? What have I done?

Can I fix this?

 

Compression is about right on the 500 since the decompression device on the cam slightly holds the exhaust valves open. Book shows 50-90 psi normal compression range. No oil isn't good though! First thing I would do is to pull the valve cover and check that the exhaust cam lobe is egg shaped like the intake lobes on both ends of the cam shaft.This was in the years of soft heated cams that would slowly grind the exhaust lobe down.This may just have now reared it's ugly head if it is the cam. As far as no oil you should have seen any oil loss from the engine if it was leaking. If you pulled the sump drain plug was it replaced? 2 quarts is all this engine takes.Sounds like you may have carb problems that may be adding to the problem also if you have gas in the exhaust system. OPT

 

Had a tarp on my gravel driveway, no oil loss?? Where'd it go? Not in the coolant... I first terrible thought was the head cracked or leaking, the anti-freeze has no foam.

The valve cover is on a wierd angle, pulling/removing it looks like a problem, can this be done w/o removing the engine? Any trick(s)?

If it is a cam prob, this seems a bit beyond my driveway abilities! Engine overhauls are real $$$. The only local guy in my town charges 85$! He's a Honda dealer, no Polaris dealer within 50 mi.

My wife is PO'd, "...you shoulda bought a new ATV...", most know how this goes...LoL!

b

 

8 mm bolts on the valve cover and a little hard to get to the top and left side,but with a 1/4" ratchet, short and long sockets it can be done. Even easier if you just pull the gas tank up a little! If its the cam you can replace it with the engine in the frame,it's not that hard. You just have the cam at TDC(cam sprocket index pin center of the head) Then DON'T move the crank. Just remove the tensioner,rocker arm blocks,pull the cam sprocket and chain off(let it drop down a little through the chain slot) and slide the cam out the left side. Reinstall in reverse order. I've simplified it a bit,but a manual would help! As far as the oil, if none shows in the tank and no leaks,someone must have forgotten to put two full quarts in! The engine sump itself only hold 8 ounces at any given time,plus the small amount in the oil filter,the rest is in the remote oil tank! PS sometimes wives do know best,but don't admit it! OPT

 

Thanks!

Your comment regarding carb prob, has me thinking!

I got distracted by my neighbour... I may (probably) have reconnected the hoses incorrectly!

Sitting on the bike, looking down at the carb...

Left side =

Right side =

b

 

Right side of carb(sitting on atv) should be the vacuum line,left side fuel inlet. OPT

 

Thought I had trashed my bike...!

Clearer mind and a warmer day.

Rmoved the carb, removed the bottom, needle valve all gunked up! Removed it, cleaned all, bike works better that ever! (Never went above 30 mph, now 45 mph!!)

Thanks for your directions! I know now more than ever about my scooter!

b

Fuel shut off stll leaks, can you direct me to a inexpensive replacement, better yet - a repair?

 

Fuel valve # 7052190 $20.21 Gasket #5810859 $1.54 at Cycle Parts Warehouse.
Repair could just be a leaking gasket,but I'd still replace the valve as it has new internal filters to help keep the trash out of the carb.Install a new inline gas filter to the carb as added protection if you haven't done so already. PS What about the oil??
OPT

 

Thanx again, man!

The oil problem was a catastorphe, so I thought... The head was full of gas, so much so, it wouldn't crank - Thank goodness!!. So, the oil was contaminated, to thin (I guess) it got into the mix and burned. That was the wierd smell, sythetic oil burning smells different, again, I guess .Changed it! Then burned it in my pit in the back yard, it WAS contaminated, full 'o gas.

So, my simple battery change cost me 3 oil changes & filters, hours of grief and dread... All caused by a gunked up needle valve!

I have run the bike, to the lake, up and down the road and all seems well - I hope!

BTW - Put in new oil 10W-40 (cheap) & filter. Cleaned the system, by cranking and compressed air, prior to refilling... So, far so good...

I'm retired as well, got the time!

Thanks again!

b

 

I know you don't want to hear this since you've burnt through 3 oil changes to get the gas out of the system,but you need a lower weigh oil (0w40 Mobil1,Amsoil,or Polaris PS4 Plus 2w50) Even T6 Rotella 5w40 is a good synthetic that I wouldn't hesitate to use,but now costs as much as Mobil1. Cheap oil is ok to clean the system,but use synthetic only or you could be dealing with a cam problem next. Even with synthetic oil there's no guarantee on the cams on 1996-2000 model 500 engines. Some haven't had problems,but many have. OPT