F90 Does Not Start???

[rougeaut]

Hi I thought I had a fuel issue but with cleaned injectors that are dumping fuel out into the intake and pooling up at the block/intake interface I know the fuel system works at 43 psi on the rail. Great Spark for each plug, comp is to spec. But after every time I try to start it and it turns over very fast sounds like it wants to start but then I check the plugs and they are dry to moist with no gas smell. I removed the plugs and turned it over with the intake manifold off and there is no blockage from the intake valve to the cylinders?
So the intake valves open just I assume not when the fuel is spraying out?
Could this be a timing issue or what it is a new motor to me but it shows the right plug configuration from the two coils as the manual indicates.
I started this new thread as the last one focused on gas/pressure but now I know it is a different animal so does anyone have any thoughts as to how to figure this out. The static timing test for TDC on #1 on the comp stroke showed the timing marks are very close.
Could this be a broken woodriff key that has thrown out the timing or such?
Note: there is a kind of white smoke only a little that comes out of the air silencer when trying to start it but I figure that is just a lean to very little gas condition?
Cheers I hope this is something that can be figured out on this forum.

[boats.net]

Have you check cam shaft timing?

[rougeaut]

Hi I checked the static timing marks and was told the timing belt almost never jumps and the belt is in great shape, I am not sure as to how to check the cam shaft timing but have a manual and will read up on it today, if not is there are there any other references as to how to do this online?
Cheerss and Thanks.

[rougeaut]

The manual I have "Seloc" shows larger motors have a camshaft position sensor(CPS) but the F90 does not have any or list any CPS in the electrical schematics. As I have checked the static timing where the two marks on the cams align at the TDC for the comp stroke for #1.

Q) Is it possible that the intake cam is out by 360' or by a revelution? IE is there a way to see the the mark is aligned and that say the intake valve on the #1cylinder just opening or otherwise?
Cheers

[ausnoelm]

I suggest you buy a GENUINE manual for your model, continuing to do what you are doing is going to get you deeper and deeper in poo, do NOT start by pulling things to bits and assuming anything, buy a manual and do the trouble shooting step by step.

[cvslawrence]

Assuming the black marks on the flywheel and bracket are your timing marks, you look to be 3 teeth off on your timing.

Close is not good enough, they must be spot on. Loosen the belt tensioner to get some slack in the belt, leave the cams where they are, turn the crank to line up the marks.

When getting the belt back in place, keep the slack on the tensioner side, no slack on the opposite side, or when tension is applied it will move your marks.

Hope this helps!

[casey1240]

By any chance, you didn't cross your plug wires to the wrong plug? Just a thought.

[rougeaut]

Hi thanks for the reply and I did try the realignment yesterday before you replied and I am not sure that I did it correctly but I losened the tensioner with the mark on the crankshaft set to TDC and then moved the cams so everything aligned I am not sure as to weather it make a diff or as you mentioned to align the cams first and keep them set and spin the crank? But it did not fire and agian no gas to the plugs??
Do you know if the intake cam can be out by 1 or more revolutions or is it set to the mark and that is that?
Cheers

[rougeaut]

Plug wire n Such

By any chance, you didn't cross your plug wires to the wrong plug? Just a thought.

Hi ya as this problem becomes more defined to the gas not getting into the cylinders I had the same thought about the plug wire not firing on the correct cylinder and it is also a new engine to me I checked the plug wiring and believe it is correct as show on the electrical schematic. The 07 F90 has 2 pulser coils the top is divied to 1 and 4 and the bottom to 2 and 3so it is wired as shown.
Not sure as to how move forward except rotate the engine over by hand and watch the valves open and close in the correct firing order?
Cheers

[ausnoelm]

so lets just recap, so far you have.... messed with the timing, pulled the manifold off, cleaned the injectors, generally fiddled around with stuff without a genuine manual to know whether what you are looking at is what you are supposed to see, I said this way back, buy a GENUINE manual, and follow the trouble shooting steps, but only after you have rectified anything you may have already messed up. Stabbing at possible faults, and playing around with the timing is a sure way to empty your wallet.

[rougeaut]

so lets just recap, so far you have.... messed with the timing, pulled the manifold off, cleaned the injectors, generally fiddled around with stuff without a genuine manual to know whether what you are looking at is what you are supposed to see, I said this way back, buy a GENUINE manual, and follow the trouble shooting steps, but only after you have rectified anything you may have already messed up. Stabbing at possible faults, and playing around with the timing is a sure way to empty your wallet.

*** I don't know why you even bother to repond to my post as you are not any help at all more of a tiny pest!
FYI It is a new engine to me, I bought a Yamaha manual the $171.00 yam manual was not in stock so for $30.00 I started to trouble shoot the engine. Now I have rebuilt a number of engines car/motor cycle/boat carbs etc even clasic Jaguar motors and transmissions, rear ends etc HAVE YOU done that much??
The motor did not start so I started with a compression test using my manual, then checked for spark, then cleaned my VST tank, filter, inlines filters all using my manual that showed these and bought a fuel pressure gauge to verify the fuel pressure was to spec. I found one sized injector and had the others cleaned with some help and good advice from others on this forum I moved forward to isolate the problem, it would seem to be a very systematic approach and now that I have validated all of the other aspects of the motor it is narrowed down to a specific issue.
This is what this forum is about or should be everyone else trying to help out either by suggesting some approach based on experience or helpfull idea not some Ya Who like you whining about buying real manual. I am somewhat enjoying working through the motor and learning about all of the components and specs. The timing I changed was only a few degrees and easy to get back to where I was. Perhaps timing scares you or removing 5 bolts to take off an intake manifold also scares you?

Stop whining to me about how you feel someone should work on a motor.

To everyone else thanks agian for your insight I am getting close to solving this issue and hope it is just a minor fix as the mian engine components seem to be all in good shape.
Cheers

[99yam40]

A lot of 4 stroke motors will bend valves if the cam timing is off.

I have no idea if your is one of those or not, but a good manual should give the proper procedure for checking.

So good luck, I hope someone with a manual for your motor will look in and have answers for you

[rougeaut]

Assuming the black marks on the flywheel and bracket are your timing marks, you look to be 3 teeth off on your timing.

Close is not good enough, they must be spot on. Loosen the belt tensioner to get some slack in the belt, leave the cams where they are, turn the crank to line up the marks.

When getting the belt back in place, keep the slack on the tensioner side, no slack on the opposite side, or when tension is applied it will move your marks.

Hope this helps!

HI Well I reread your comment and retried the static timing not as easy as it sounds and after a couple trys I got the motor started!!! it was so close that it was actualy almost starting when you turned it over it started turning over faster and faster but wouldn't quite get there then after readujsting it and it being so close I just let it sit for a bit and then tried it with no choke or fast idle and now it does the same thing consistantly: It turns over for about 3 seconds, starts runs for about 3 seconds then dies? The fuel bulb is full and tight and I can restart it time after time but with the same results.
Very Happy sound to hear it start for the first time and number of beers were sacraficed. Now I just need to figure out why it is dying.
FYI I popped off the flywheel cover I made a tool that my manual sugested to hold it and retorqued it to 137 lbs. The woodroof key was in great shape so that was another possible cuase eliminated at no cost.
The manual states do not try the timing light on it unless it is under load so I guess that is something I can not do at this point?
Anyway I just want to say THANKS for your comment it lead me to redoing the static alignment with the tension as you mentioned tension on the intake side of the belt.
Cheers n Beers

[rodbolt17]

recheck your compression AFTER making sure the TDC is correct AND the cam marks line up correctly.
the F90 is an interfernce motor and WILL bend valves if cam timing s off.
it also doesnt like to start if the throttle is advanced.
check rail pressure wen it dies.

[ausnoelm]

*** I don't know why you even bother to repond to my post as you are not any help at all more of a tiny pest!
FYI It is a new engine to me, I bought a Yamaha manual the $171.00 yam manual was not in stock so for $30.00 I started to trouble shoot the engine. Now I have rebuilt a number of engines car/motor cycle/boat carbs etc even clasic Jaguar motors and transmissions, rear ends etc HAVE YOU done that much??
The motor did not start so I started with a compression test using my manual, then checked for spark, then cleaned my VST tank, filter, inlines filters all using my manual that showed these and bought a fuel pressure gauge to verify the fuel pressure was to spec. I found one sized injector and had the others cleaned with some help and good advice from others on this forum I moved forward to isolate the problem, it would seem to be a very systematic approach and now that I have validated all of the other aspects of the motor it is narrowed down to a specific issue.
This is what this forum is about or should be everyone else trying to help out either by suggesting some approach based on experience or helpfull idea not some Ya Who like you whining about buying real manual. I am somewhat enjoying working through the motor and learning about all of the components and specs. The timing I changed was only a few degrees and easy to get back to where I was. Perhaps timing scares you or removing 5 bolts to take off an intake manifold also scares you?

Stop whining to me about how you feel someone should work on a motor.

To everyone else thanks agian for your insight I am getting close to solving this issue and hope it is just a minor fix as the mian engine components seem to be all in good shape.
Cheers

not trying to insult you in anyway, or doubt your mechanical prowess, just pointing out that stabbing at "maybe" will usually get you nowhere, as mentioned, that engine is going to cause damage if the timing is not right.