HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
tnl

Bike won't start

14 posts in this topic

I have a 05 450 with 60 hours on it and just replaced the cam chain with tensioner last weekend and installed a Dr. D 6oz flywheel and checked the valves and put a new spark plug in. After I reassembled everything and tried to start the bike it wouldn't start so I pulled the cam covers off and rechecked the cam timing and the crank timing and noticed the intake cam was off about 1 tooth. I then retimed the intake cam (didn't touch the exhaust cam) and reassembled things only to have the same problem? Then I replaced the new plug with the old one and that still didn't work? I made sure that the plug had spark which it did, carb has fuel flow too. I forgot to recheck the intake valve clearences though? Could this be the problem?

Share this post


Link to post
Share on other sites

Are you sure you lined up with the timing mark? I did the same thing on my old (and gone) CRF450. It looked like it was lined up, but when I got my eyes exactly level with the mark, I was still off.

Share this post


Link to post
Share on other sites

Does it have good compression?

When the cam was out of time, was it rotated too far forward, or too far rearward?

Share this post


Link to post
Share on other sites

The cam marks are as even as I could eye them up by lining my line of sight level with the top of the cylinder. The intake cam timing mark was about at the 2 o'clock position rather than the 3 o"clock position where it should of been. I only adjusted it by 1 tooth. And it does have good compression. I noticed that the new plug I installed has a different part # digit cr8e rather than a cr9e in it but everything looks the same including the gap that I checked? I also made sure that the plug cap is snapped on properly. When I rechecked the timing I rotated the crank about 2 revolutions to make sure that it didn't jump the chain or get misaligned and rechecked the crank timing and the cam timing looked good so I reassembled things.

Share this post


Link to post
Share on other sites

Here's another question? With the Dr. D. 6oz flywheel what timing mark am I suppose to use on it? It has 3 indicators on it: #1. the blue stamped circle. #2. the vertical slash (this one lines up at T.D.C. Screwdriver in the plug hole method), #3. the symbol that looks like a H? Gotta call Dubach Racing tomorrow?

Share this post


Link to post
Share on other sites

If you're certain the timing is correct Check for spark, if I recall correctly you had to remove the stator and flywheel, make sure non of the wires are not damaged and your plugged back in.

Share this post


Link to post
Share on other sites

Got a good spark all the way out of the plug! It back fired/poped one or two times while pushing it down the street-gave it one twist of the throttle. The plug is getting fuel too? Piston is definately at tdc? Pulled the plug to let it dry out overnight and blew air in the plug hole too?

Share this post


Link to post
Share on other sites

Was the plug wet? It is possible that you totally flooded it when you first tried to start it. That happened to a friend of mine....We ended up pull- starting it with his truck at Glen Helen.

Share this post


Link to post
Share on other sites
Here's another question? With the Dr. D. 6oz flywheel what timing mark am I suppose to use on it? It has 3 indicators on it: #1. the blue stamped circle. #2. the vertical slash (this one lines up at T.D.C. Screwdriver in the plug hole method), #3. the symbol that looks like a H? Gotta call Dubach Racing tomorrow?

I believe the timing mark that lines up with the woodruff key is the one that matters. The woodruff key should be on the top of the crank directly in line with the cylinder/piston movement.

On a side note, you have fuel, right? :thumbsup:

Share this post


Link to post
Share on other sites

kick the shit out of it, literally, thats what i do, i rebuilt my 426 three times first two times it fired on the first 10 kicks the last time i kicked it for an hour, and eventually tow started it.

Share this post


Link to post
Share on other sites

Called Dubach Racing this morning and was told to use the middle timing mark on the flywheel! That is the one that I used last night so I'll try again this morning to re kick/bump start it and let you know how it worked out. I already kicked the heck out of it yesterday but maybe it needs some more?

Share this post


Link to post
Share on other sites

Found the problem!! The crank rolled just a little off of T.D.C. (just off the timing mark 1/8") while one of the cams were being timed...It doesn't take much pressure to roll the crank when it is at T.D.C. to throw it off when messing with the cams? Just by applying a little pressure to the exhaust cam while i was holding it in place was enough to roll the crank 1/8" off the timing mark. I thought I rechecked the crank but ??? Anyway, 1 foot blister and about 10 pounds of sweat later it's up and running...

Share this post


Link to post
Share on other sites

Do I get a prize? A cookie? Some fuel perhaps?:thumbsup: :thumbsup:

1 person likes this

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0