YZ426F No Start

After cleaning the jets in the carb, and pilot, the bike now runs! That's all that was needed. Thanks to absolutely no one on this thread for your help, but thanks for your suggestions of timing for a whole 2 pages.

Hmmmm. Good luck in the future. Maybe next time don't start with images of timing issues. Not to mention the cam marks are in the wrong place.

Hmmmm. Good luck in the future. Maybe next time don't start with images of timing issues. Not to mention the cam marks are in the wrong place.

 

The timing marks were correct as presented, providing that the engine is at TDC. 

 

nv4afbR.jpg

Why would that sprocket have timing marks every 90?

Because that's the way YZF cam sprockets were made pre-auto decompression.  That way they were able to use the same sprocket on either camshaft.  There are only 3 marks.  Originally, the one at 9:00 was marked with an "E", and the one at 3:00 was marked with an "I".    

Hello all.

Not to hijack a thread but I am having the same issue with a 2000 426.

In the pics of cam timing marks posted, the first one from supermoto shows 14 pins between the top marks. The Photo from mlcompound shows 12 pins and the photos in the instructions that Supermoto posted shows 13 pins.

I know grey has discussed that pin count is not the way to time the cams, but how can 3 different bikes have so much difference in pin count? That's close to 12mm diffference. I understand the cam to sprocket could be different but when the sprockets appear to be timed correctly with a different pin count, it doesnt seem right.

Is there a correct pin count or do some end up at a different count than others?

Edited by yzhaulin

The pin count between "12:00" marks varies by model (mostly), and when you throw aftermarket parts into the mix, it varies some more, since the manufacturers may use sprockets made for one model on another.  There have been several versions, and the pin count will range between 12 and 14, depending on whether it's a 400 or a 450, original or aftermarket, manual or automatic decompression, or whether it's a WR instead of a YZ.  What their original purpose was is somewhat lost knowledge.  They can be useful as an assembly aid for installing the second cam in time on the first attempt, but only if you know what the count should be for your particular bike. 

 

Read: http://www.thumpertalk.com/topic/639348-07-yz450f-valve-adjustment/#entry6331731

The timing marks were correct as presented, providing that the engine is at TDC.

Your right sir, timing was not the case here, it was the pilot jet in the carb. It had crud in it from the month it was sitting while the top end was being rebuilt. Here a video for the non-belivers.

nv4afbR.jpg Edited by YZ426Supermoto

If y'all wanna help out, I'm interested in doing a rear handbrake. Is there anyone who can give me suggestions?

I'm sure people will be queuing up to help you after this thread???

I'm sure people will be queuing up to help you after this thread???

Your probably right, I'll get suggestions like "your brake isn't calibrated, your brake level needs to be flush with the master cylinder"

Search it a bit.  Left hand rear brake (LHRB) has been brought up before a few times.  

OK. In this pic look at the timing marks on the cam sprockets. They are left up left up.

the cam chain is too loose between the cams. There should only be 12 or 13 (cant remember) pins between the timing marks between the exhaust and intake cam. You have 14 pins between the marks.

In the first place, you CANNOT use the pin count between the 12:00 o'clock marks on the cams unless you know for a fact what it was to begin with.  There have been YZF models with 12, 13, and 14 pin counts as correctly timed.

 

Secondly, you may have missed POST #28

I can assure you I'm dead on. The cam chain is loose because the tensioner is out? Its a brand new chain. Even if the timing in 1 tooth off, it should still start. Its not 180 off, as that's impossible since I set TDC.

I counted 14 links between the two 12 o'clock marks. It supposed to 13

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