I am having problems with a single cylinder bike engine that I rebuilt. The mark on the cam will not line up when crank is at TDC. it isn't a lot out, and moving a tooth makes it a lot worse.. how critical is this? I havent measured it but i would guess it is a degree or 2 out. I am guessing someone skimmed the head previously or something and it isn't a big deal but would like conformation from somebody who knows!
2007-10-13 20:52:32 · 6 answers · asked by kevsticle 1 in Cars & Transportation ➔ Motorcycles
And it isn't a mixture issue, had to move needle to bottom clip just to get it ridable at all and main jet is a new standard size. It is CDI.
2007-10-13 21:29:20 · update #1
Cam chain hasn't been on there long. DR600.
2007-10-13 22:11:44 · update #2
As much as two degrees could too much
2007-10-13 21:06:56 · answer #1 · answered by The Rugby Player 7 · 0⤊ 0⤋
Make sure your cam chain has tension on it before worrying too much about marks lining up. Had the same problem with a Kawasaki Z250 years ago. I ended up turning the crankshaft backwards a bit, maybe 10 degrees, then forwards to line up the TDC mark again. found this put tension on cam chain, and ensured the cam was right.
Just had another thought. How much of a rebuild did you do? See you have a DR 600. Assume this is a single camshaft four valve or similar. (I ride road bikes) Did you remove the cam sprocket from the shaft? Make sure the sprocket is not 180 degrees out. On my Z this made a reasonable variation. The sprocket had a line all the way across it, not just a timing mark.
On your carbie needle setting, check your butterfly valve. usually the needle sits on the mid-point setting. Sounds like your butterfly is out. All this depends on how much of a rebuild you did. (strip and rebuild carbie, replace gaskets, bottom end, top end, rings, hone bore,etc, etc.)
Good luck with it.
2007-10-13 21:26:57 · answer #2 · answered by Peter 1 · 0⤊ 0⤋
You are unclear as to what you are trying to line up. The camshaft would not normally line up with it's highest point to the Crankshafts TDC. The inlet and outlet valves would open a little before and a little after TDC. On a high performance engine this would be critical and but on a low performance single cylinder motor a degree or two is not going to be important. The important points are the shoulders of the camshaft when the valve is just starting to open this can be before TDC even on the exhaust cycle.
2007-10-13 21:10:59 · answer #3 · answered by richy 1 · 0⤊ 0⤋
Lot's of Jap bikes have the cam timing marks not in the exact position.
Why? Good question LOL
Just set it to the closest position.
Turn the crank slowly 360 degrees to make sure a valve isn't hitting the piston.
2007-10-14 07:44:11 · answer #4 · answered by guardrailjim 7 · 0⤊ 0⤋
It would help if you told us what bike it is.
For example, Honda XL/XR 125/185/200 don't really care if the timing is out several degrees. Usual cause is worn chain.
I'm suspecting its either Honda or Yamaha.XT
Suzuki SP/DR are not so common and the Kawasaki's tend to kill the chassis as well as engine so make rebuilding uneconomical
2007-10-13 21:33:36 · answer #5 · answered by 1crazypj 5 · 0⤊ 0⤋
setting your timing this way is not the best way to set it up but if your not to worried about loosing a couple of hp then it will be fine if you are i would suggest you take it to someone who can degree the cam in.
2007-10-13 21:08:41 · answer #6 · answered by Anonymous · 0⤊ 0⤋