I went to set the valves and noticed that the cam timing marks did not line up when i locked the crank at tdc. I got the intake to line up perfectly by jumping the chain by 1 tooth. But the exhuast does not line up. Its out a 1/2 tooth. How can this be. The chain is tight, had to take all the guides and tightener out and it was still hard to get the chain to move so i don't think its streached. Can i get the exhuast to line up or is that the way they are? Which way should it be out advanced or retarded? Should I degree the cam to find out where it really is or is it not that important?

 

Unless the motor has been apart or performance is down, I would suspect the process you're using to check them, not the cams themselves.

I ain't saying you're wrong wrong about what you're seeing, but I am saying you should question the what, why and how that got you to the point you believe they are incorrectly set.

Sorry for not being more help, but for me, stepping back from the forest before chopping down trees seems to help.......especially for me.

jbt
"aka - chainsaw kid"

 

see my post under "tach rpm" I have no one to ride with so I have nothing to compare it against. It is winter, and most everyone is ride snowmobiles. I think power is down becouse everyone talks about hitting the rev limiter, and I can bearly hit it in 1st gear. It doesn't pull that hard past 6000rpm. I will adjust the valves and put it together and check it out. I know the intake was out 1 tooth. I turned the engine over a couple of time and it was always the same. The exhaust I don't know. It doesn't line up no matter how many times I check it. It is out 1/2 a tooth. It looks like a picture I seen on a bmw f650 site http://faq.f650.com/FAQs/Valve_Shim_Check_FAQ.htm. The intake lines up but not the exhaust. Anyway the intake valves are super tight--can not get .0015" gauge to fit. So I hope this helps the starting.

 

Have you checked to see if you're jetting is on? A 3" cap in the real cold weather with average humidity would require some stiff jets. Do you have the lid on or off with the 3" cap?

Not hitting the rev limiter in 1st could be either lean or rich depending on when you try. Generally, if you can't hit the limiter in 2nd or 3rd, I'd guess a little fat depending on the rest of the bike mods and how you have it set.

Add some more info like brand and size of jets, airbox mods, elevation, ambient temp and humidity. Saskatchewan sounds mountianous and cold.

Tweaking cams is a heavy gig, unless the motor has been previously open'd.

jbt

 

I put it together with the intake lined up(out one tooth factory) and the exhaust advanced 1/2 tooth and it run awsome. I looks like my jetting is super lean!!!!. I have never seen such a white plug. I was surpised I didn't have a bunch of detonation. It is stock jetting and I just ordered a 175 main from the dealer PS are these standard mikuni round jets or are they something else. Saskatchewan is cold and flat--middle of the praries. Elavation is 2000' and it -10c or so which is not bad temps for this time of year. It get to +40c in the summer. The lid is on and the air is dry.

 

175 sounds like a definite good starting point. I run a 175 with the needle all the way up at sea level. Its a tad fat, but the mid range comes on better. Plus, I can go leaner real fast when I go up in elevation by just dropping the needle.

Tweaking the cams changed when the yam 450 power comes on, but I've heard rumors some folks are going back to stock to get the mid range power back....like to find some real dyno curves of this. Most the curves I've seen added other changes like exhaust or carb setting. Not just the cam mod.

-10c ?? I was working in the garage in short sleeves last night with the door open.

jbt