can a camshaft be installed upside down?

[kilabeez0]

I've tried everything. i'm sure my carb settings are all messed up but even so i thought that it would MAYBE fire up. i rebuilt this thing top to bottom, i'm just not sure which direction i installed the cam, lobes up or down? I pulled the CDI cas off and the stator case, i had the magneto on the T mark with the notch on the case, as well as the CDI thing lined up with the rubber piece with a notch in it. My only other idea is that maybe the cam was installed wrong? Any ideas?

~Last night when i discovered the hole in the gas tank i kicked it over anyway and it fired up for like a split second and that was it. :o

[bigredhead]

New plug?

Clean air filter?

Fresh gas?

choke not stuck by any chance?

valve clearance checked?

It don't take much to make a non-running motor.

sorry i don't know about the cam tho.

[MTS]

yes it is possible to install the cam 180 degrees off, the lobes have to be facing DOWN when you install it

[kilabeez0]

it sounds like my timing is correct though right? I have all those things listed except the valve clearances. When i had my top end rebuilt, or atleast he just did the valve seals, he told me the valve seats were worn out alot and I need to adjust the clearances. I kind of have an idea how to do it, but i dont have the manual with me, shouldn't it atleast fire up even if they're off?

[vartiak15]

i put mine in and i could get it started so i rotated the cam 180 degrees and it worked

[MTS]

hear is how to adjust your valves http://www.3wheeler.org/dirtwheels/6-87~tuneupindex.html if your valves are set too tight the bike will not start, and if they are too loose bad things will happen lol

[kilabeez0]

interesting article. there can be 2 TDC's??? i never knew about that, the compression stroke and all. i'm also not sure if i adjusted them right, all i know is that it finally started!!! my feeler gauge has a number on the top and one on the bottom, one is mm and the other is inches, i dont know which is which, but i did the .003 one, or maybe it was the .03 which would be incorrect but hey it worked!

[mwill15]

In a four stroke engine, the piston reaches tdc on the compression stroke and then again on the exhaust stroke. Your cam must be in sequence with your crank. If not, then it is 180 off and your vales will open and close at the wrong times. In this case, though, the bike will not run at all; this isn't your problem. You stated earlier that the trike ran briefly. Try the valve lash.

[HaggLE]

The comments below are regarding a 200x motor (you didnt say)

Firstly, the way you timed the cam is wrong. You dont line up the CDI thing with the rubber piece with a notch in it, There is a mark on the cam chain sprocket (which is behind the ignition back cover) that lines up with a mark in the casing. That mark should line up when the "T" is visible in the hole. The cam lobes should be pointing down also (both valves should be closed). Sometimes the marks wont line up perfectly depending on cam chain wear. As close as it gets is right.

Secondly, the ignition timing, which is that CDI thing and the rubber piece with a notch in it should line up with the "F" mark visible in the hole. But im not sure whether is with the CDI thing sprung out or in. Just try both and see which runs the best.

With the cam chain tensioning, i find that the little spring in the adjuster isnt enough to get the chain tight. If you look close there is a thread in there that will fit a bike spoke to screw in. Screw a spoke in there and pull up to give the correct tension and tighten the locknut. If you dont have an old spoke, take the flywheel cover and flywheel off and push the adjuster manually and then do the adjuster locknut up.

[83185s]

yes lobes must be down..the tdc has to be on compression stroke..if your flywheel is on then line it up with the t and itll be on the comp stroke..it helps if u take out the spark plug tho..if it did this it may be trailprotrailpro pulse rotor..the little thing u have to take off in order to get to the timing chain on the cam..u can take it off and rotate it 180 degrees..(only the rotor) not the whole thing

[kilabeez0]

The comments below are regarding a 200x motor (you didnt say)

Firstly, the way you timed the cam is wrong. You dont line up the CDI thing with the rubber piece with a notch in it, There is a mark on the cam chain sprocket (which is behind the ignition back cover) that lines up with a mark in the casing. That mark should line up when the "T" is visible in the hole. The cam lobes should be pointing down also (both valves should be closed). Sometimes the marks wont line up perfectly depending on cam chain wear. As close as it gets is right.

Secondly, the ignition timing, which is that CDI thing and the rubber piece with a notch in it should line up with the "F" mark visible in the hole. But im not sure whether is with the CDI thing sprung out or in. Just try both and see which runs the best.

With the cam chain tensioning, i find that the little spring in the adjuster isnt enough to get the chain tight. If you look close there is a thread in there that will fit a bike spoke to screw in. Screw a spoke in there and pull up to give the correct tension and tighten the locknut. If you dont have an old spoke, take the flywheel cover and flywheel off and push the adjuster manually and then do the adjuster locknut up.


man you guys are really being helpful!! thanks alot for all the different things to check, this board is very helpful. anyway, i wonder if my having the cdi notch aligned with the rubber piece while the crank is on the T mark, than maybe my timing is WAY advanced causing it to run hot and turn my header orange???