While cleaning up the wives sled for the summer I was inspecting some "oil" under the exhaust pipe on the PTO side head/block only. I saw some leakage last year but didn't think much about it. The sled has 2019 miles on it. The exhaust doesn't seem to be leaking as I examined it with a mirror. The jugg gasket could be leaking in this area.

What to do?

Should I ignore it as it isn't a great amount and it is only on the one side? Should I take the Y pipe off and put new gaskets on the exhaust and seal them with Permatex in case it is the exhaust? Should I take the head off and the jug and put a new gasket in? Should i continue to ignore it and if I go and the jugg gasket needs replacing, will I burn down that cylinder?

If I start up the sled and let it get to operating tempature, will the leak be evident now or does the sled need to be under a load?

Also, this machine engages the clutch around 4100 RPM, can I go down a clutch spring some it engages around 3500 RPM, if so will it loose some top end?

Thanks!!

I have had the same exhaust leak several times on my 99 ZL 900.
Twice it was caused by a split seam on the Y pipe. I had the seam welded and problem went away. You should be able to feel the hot gas if the Y pipe is split.

Next time, it was the metallic gaskets between the Y pipe and the cylinders (when I took it off, my Y pipe was warped a little). I put it back on with the old gaskets and Permatex and solved the problem.

I have also had oil leaking from the gasket at the outlet of the Y pipe. Permatex helped here but did not completely eliminate the leak.

My leaks were made worse because I was using oil at between 25:1 and 35:1 to a worn cam in my oil pump.

Most times they leak around the exhaust gasket, black sticky sludge runs down the block, had to replace them a couple time on my 500, last time I put gasket seal on and seem to stop, If the sled is using alot of oil it adds to the problem.

If the leak is from the exhaust flange / gasket area be careful about tightening the nuts too tight. Over tightening the exhaust nuts can warp the flange on the y-pipe and then the gaskets won't seal very well. Check the flange for flatness and true it up with a file if it is warped. High-temp copper RTV can be use to help the seal.

I don't think you want to lower the engagement RPM. The small engines need to rev to make power and if you go any slower you will probably have severe bogging. 4100 even sounds low to me, but I've not ridden the 500 for myself.

Yes,, The 500 engages near 5000 stock, your quite low now ,any lower will hurt performance, even 4100 it won't have the snap it should.

The stock engagement on my ZL500 is 4800. However, I always found this to be too high so I changed the spring to drop it to around 4500. While I did give up some of the 'snap', I found it to be a more enjoyable sled on the trails because the primary did not drop out so quickly when you got off the gas.

The lower engagement is nicer for trail riding, especially in woods trails where you need to run slower, doesn't disengage the clutch as quick, probably easier on the clutch in the long run, if performance is not an issue the lower engagement is probably best., however I would't go any lower than the 4100, but that's just me.

Thanks to all for the replys.

I'll check the pipe and seal the gaskets, does anyone know the torque for the y-pipe nuts?

As far as the clutching goes, the sled is mainly used in the woods and by my wife. She handles it fine as is, but she wouldn't know any difference about how another machine would engage as she hasn't rode any other sled for 4 years. Maybe if it ain't broke, I shouldn't fix it.

Found the leak, it was the y-pipe exhaust gasket. Cleaned everything up and applied the high tem red Permatex and put it back together.

New issue. I want to adjust the oil pump. It is using about a 38-1 ratio. Can it be done from above or should I just remove the bellypan and get at it from below?

It can be done from above,, done mine a couple years ago, take the sec off, or you can also remove the carb on that side to make it a little easier, there pigs from the factory,, hard on y-pipe gaskets. :lol2:

I've done lots of work on my oil pump because the ratio dropped to 25:1. I have found it pretty much impossible to get at the cable adjuster without taking the trottle bodies and airbox off (big hands!!). Removing/installing the airbox is a 'pain in the ass' job because AC squeezed everything in there so tight.

The oil ratio dropped because of wear on a cam inside the oil pump. Even with the cable quite loose at idle, my oil ratio was still quite low. You may have to bend back the idle position end travel tab on the oil pump lever if you want to raise your ratio.