Timing Help Needed. Pics Inside.

[bhsballer76]

Today was the first day i worked on my crf450 in about two monthes. The last time i worked on it i was adjusting the valves. The problem is that the bike did not run afterwards. I was told to check the timing and after doing that the bike still would not run. I got busy with work and school so the bike just sat in the garage.

So today i started to work on it again. I decided to should start by checking the timing again but i have few questions to make sure i am doing it right. I know its alot to read, but if you can help me out that would be great.

1.When the motor is at TDC should the cam lobes be facing directly toward the shock at a 90 degree angle (like pic 1) or should they be pointing slight upwards(like pic 2).

Here are some pics as it is right now. The lobes are pointing towards the rear shock but also at a slightly upward angle. When i move the cam lobes to face directley towards the back, the piston is not at its highest point.I can tell it is about a 1/4 of an inch lower b/c of a screw driver i have placed in the spark plug hole. In order to get the piston and screw driver at the highest point, the lobes must me moved to where they point slightly upward and to the back.

2. How can you make sure the "tick" mark on the cam gear is properly aligned with the cast trianle marks?? It seems like depending on what angle you look at them, they can appear to be perfect or they can appear to be not aligned at all with out moving the cam gear at all?? Here are som pics so you might be able to see what I am talking about.(these we taken with out the cam gear moving at all)

3.As it is right now the all the the markings on the ignition side access hole do not seem to light up. To get the "mark" to be with in the "two marks" i would have to rotate the "two marks" slightly clockwise. I was not able to get any good pics of this.

4. On the clutch side access hole the two "punch marks" appear to be lining up correctly.(both these pics were taken with out moving the cam at all)

So if anyone can answer any of my questions or maybe comment on what i might be doing wrong that would be great. Thanks.

[PBWR450]

I'm new to the CRF's but have checked the valves on my 02 a few times. I have noticed with the piston at TDC the cam lobes do point upward slightly as in your picture and the mark on the cam lines up with the triangle when you look at it level, just like your first cam gear picture. The timing marks on the crank bolt should then line up as well when looking at it level. I assume you are checking this with tension on the cam chain? Did you adjust the valves when you last checked them and, was it running well before?

[bhsballer76]

I'm new to the CRF's but have checked the valves on my 02 a few times. I have noticed with the piston at TDC the cam lobes do point upward slightly as in your picture and the mark on the cam lines up with the triangle when you look at it level, just like your first cam gear picture. The timing marks on the crank bolt should then line up as well when looking at it level. I assume you are checking this with tension on the cam chain? Did you adjust the valves when you last checked them and, was it running well before?

here is what happened.I bought the bike and after doing some research decided i better check the valves. This was my first crf and i had never done a valve adjustmetn before. It was pretty easy and stright forward but when i finished the bike would not start....I was told i should check the timing and thats what i did. The bike still would not start..that was a few monthes ago..

I put it on a stand today to try to figure it out but decided i better make sure the timing was right before i moved on to anything esle..

[JJRace]

YOu need to look at the timing marks on the flywheel. Other side of the motor. It will be the left of the 2 hash marks there when the cam is timed to the arrow.

[berudd]

definitely use the timing marks on the ignition side, they are easier to line up correctly. I was told by good mechanics that if you shim the valves and the bike is still hard to start or will not start, then your valve seats are shot and need to be re-cut or worst case, replace the head. Make double sure you have the timing correct. I think that if you can turn the engine over by hand, you are safe and the piston and valves are not hitting each other. Try to bump start it. I was in the same boat and when I had convinced myself I was timed correct I bump started it and it ran fine. You just don't have enough compression to kick start it. And once it warmed up, I was able to kick start it just fine.

[bhsballer76]

definitely use the timing marks on the ignition side, they are easier to line up correctly. I was told by good mechanics that if you shim the valves and the bike is still hard to start or will not start, then your valve seats are shot and need to be re-cut or worst case, replace the head. Make double sure you have the timing correct. I think that if you can turn the engine over by hand, you are safe and the piston and valves are not hitting each other. Try to bump start it. I was in the same boat and when I had convinced myself I was timed correct I bump started it and it ran fine. You just don't have enough compression to kick start it. And once it warmed up, I was able to kick start it just fine.

I was able to bump start it a few times when i last worked on it a couple of monthes ago. As soon as it would start it would run like crap and only for a few seconds. I would try to keep it running and it just would not stay running at all..

[Ervin]

If you can git a spark with the screwdriver but not with the plug then you must change the plug. Ervin.

[JJRace]

You may have more issues than valves and timing. Check the spark, double check the timing with the timing marks on the flywheel.

The right side of the motor punch marks are to line up the crank with the balancer. Not to be used with timing the cam. That is what the timing marks on the flywheel are for.

After that, carb issues. Most likely the hotstart being open. Lube the plunger, clean the bore and then adjust the freeplay in the cable.

[turboandy]

Acording to the bottom photo you are 1 tooth off. Look parallel to the marks.

[David C]

I`ve seen pics on here where the marks are not lined up perfect on some bikes. Take out spark plug and put in a straw or something like it, rotate motor untill the straw hits it`s highest point and the lobes are faceing rearward. Then check your marks and see how far off they are.

I only check the cam gear marks on mine and the kids 250s, if they are off a tooth it make a hugh differance in how they line up.

[bhsballer76]

I`ve seen pics on here where the marks are not lined up perfect on some bikes. Take out spark plug and put in a straw or something like it, rotate motor untill the straw hits it`s highest point and the lobes are faceing rearward. Then check your marks and see how far off they are.

I only check the cam gear marks on mine and the kids 250s, if they are off a tooth it make a hugh differance in how they line up.

ok, so what if i get the piston at TDC( using a straw or screwdriver) and the lines on the igniton side dont match up.. How would i fix this?

[NorCalRider]

Your pics look good. You are right about the cam lobes point rearward but slightly up when at TDC on the compression stroke.

Timing marks never look perfect in pictures due to angles and light etc., but even if your timing was off by one tooth either way, the bike is still going to fire.

I'd say you've got something else going on. I'd start with a new plug, fresh gas and clean your carb.

[David C]

ok, so what if i get the piston at TDC( using a straw or screwdriver) and the lines on the igniton side dont match up.. How would i fix this?

You wont be able to, but you`ll know where your at timming wise. If the piston is at TDC, the marks on the crank and ignition doesn`t matter. The only thing they do is tell you that your at TDC, and you`ll already know that with the straw. The only marks i use are the cam gear marks. If they are off just a little you know it`s in time. If you take the chain loose and move it one tooth one way or the other you`ll see how far off they will be, it wont look right at all.

[bhsballer76]

Your pics look good. You are right about the cam lobes point rearward but slightly up when at TDC on the compression stroke.

Timing marks never look perfect in pictures due to angles and light etc., but even if your timing was off by one tooth either way, the bike is still going to fire.

I'd say you've got something else going on. I'd start with a new plug, fresh gas and clean your carb.

Well i cleaned the carb out yesterday. I am about to go get a new plug. The odd thing is the last time i worked on it a few monthes ago i could bump start it but it would run horrible and only for a few seconds before it would die.

[bhsballer76]

You wont be able to, but you`ll know where your at timming wise. If the piston is at TDC, the marks on the crank and ignition doesn`t matter. The only thing they do is tell you that your at TDC, and you`ll already know that with the straw. The only marks i use are the cam gear marks. If they are off just a little you know it`s in time. If you take the chain loose and move it one tooth one way or the other you`ll see how far off they will be, it wont look right at all.

So you are saying that my timing looks to be good?

[JJRace]

So you are saying that my timing looks to be good?

Dude, you need to check the timing marks on the flywheel. Do it and move on with your checklist if you still have problems.

[David C]

So you are saying that my timing looks to be good?

IMO, all but the 6th pic of yoor gear, that one looks one tooth off, 1-5 looks perfect.

[bhsballer76]

ok...Well i put the valve cover back on and hooked up the gas tank. It did start after about 15 kicks. It was running very poorly and did not want to idle. I repeated this about 3 times and then it finally started to idle on its own. The only problem was that it was popping like hell and was shooting small flames out of the exhaust. I took it down the street to try to gauge the power and it felt good except for all the popping.

I pulled it in the garage and tried to start it and the kick start was very hard to kick. I mean it did not want to budge. I rolled the bike back and forth a few inches and i was able to kick it but only from about half way down. It seems like if the lever went all the way to the top, i can not kick it and have to roll it a bit to be able to kick it..

So can anyone give me some help from this point forward..

The good is i got it to run..

The bad is that it popped way too much and now the kick start is very hard to kick..

[NorCalRider]

Being hard to kick sounds like the decompressor is out of adjustment or the timing is off by one tooth. I've had that happen before, the bike is really hard to kick over, you really gotta put your leg into it to get the motor to turn over. Your timing could of jumped a tooth if the tensioner backed out or if the timing chain is really worn out. I'd check the timing again. Make sure the decompressor is adjusted properly, make sure you've got the nut tighted up to keep the pin from loosening.

The popping and flames sounds like the carb is really lean, you've got an intake leak around the carb boot, or maybe a leak between the head and the header.

[bhsballer76]

Being hard to kick sounds like the decompressor is out of adjustment or the timing is off by one tooth. I've had that happen before, the bike is really hard to kick over, you really gotta put your leg into it to get the motor to turn over. Your timing could of jumped a tooth if the tensioner backed out or if the timing chain is really worn out. I'd check the timing again. Make sure the decompressor is adjusted properly, make sure you've got the nut tighted up to keep the pin from loosening.

The popping and flames sounds like the carb is really lean, you've got an intake leak around the carb boot, or maybe a leak between the head and the header.

Ok, thanks for the info. I will be sure to check all of the those things.

The kick start is reallly hard to kick. My first thought was that the engine was locked up.

As far as the jetting being lean, how can i fix that?? Would the flames out of the exhuast indicate that its lean or rich??