New motor Won't Start

[steve n carol]

Re: New motor Won't Start

Fishingtime, the crank key! good idea. Do you think it possible to have bent a valve or two with all of this?

 

[qystan]

Re: New motor Won't Start

Sydmoe<br /><br />There's a lot of posts. I might be repeating what someone may have already mentioned. <br /><br />Lining the timing mark puts you in one of 2 possible positions: #6 TDC or #1 TDC.<br /><br />If you set the rotor to #1 when the engine is at #6 TDC, it will never start.<br /><br />To confirm, line up the timing mark. Remove the left rocker cover, look at the #1 cylinder valves. Both must be in closed position (not depressed). If it isn't, turn engine over by 1 rev and you should get #1TDC.

 

[Fishingtime]

Re: New motor Won't Start

Hi Steve n Carol,<br />Bent valves would happen only if the cam timing were several teeth out of adjustment. If crank pulley key is missing or sheered it would make it impossible to get proper ignition timing. The popping out of the exhaust described by Sydmoe sounds like very retarded timing opposed to very advanced timing that would cause the motor to kick back. Another way to verify crank pulley position is to get #1 piston up on top then look to see if timing mark on crank pulley is sitting on TDC. The crankshaft must turn two full revolutions in order to turn the camshaft one revolution so if crank is on TDC for compression when you turn it one revolution (360 degrees) it will be on TDC for exhaust. I know that a lot of this stuff is really basic, but it is where I cure a lot of my problems. Another thought is if there is a low popping out of the exhaust indicating retarded timing try turning the distributor to advanced timing to see if motor will start kicking back. The correct timing will be somewhere in between.<br />Fishingtime

 

[Sydmoe]

Re: New motor Won't Start

Thanks for all your input guys. I was so frustrated trying to figure this thing out for the last 2 days that I decided to give it a rest today. I instead took out my 21' cuddy with the dependable 3.0L Merc. I actually was suppose to put it up for sale last month but thought I would wait till I got the new motor in the 25 footer which has had a bit of a glitch. Its good to have a spare boat for times like these <br /><br />I pulled out all the spark plugs and will start over again. I noticed all the plugs were fuel saturated so letting it sit all day to dry out is probably a good thing. I can't imagine shearing of the crank key. I would have noticed that I am sure. I will keep you guy informed.<br /><br />Thanks again for the contiunued support on this one.<br /><br />This place is the greatest!!!!!!!

 

[steve n carol]

Re: New motor Won't Start

SYD, What fishtime meant is not only shearing but also "rolling" it out during installation. Done this myself on 2 different GM SB. Take a rest. It's over 100 deg here today. Were are hiding, and resting.

 

[Sydmoe]

Re: New motor Won't Start

I am 100% i lined up the balancer to the key on the crank before I bolted it down. What exactly is meant by "rolling". Do you mean not lining the keyway up and simply crushing the key????

 

[Sydmoe]

Re: New motor Won't Start

o.k.....I finally found a capable helper to crank the engine while I tried to re-determine TDC for the 15th time after removing all spark plugs. While I had by finger over the #1 hole (not play dough this time) I noticed that on what should be the compression stroke with both vales closed my finger is getting sucked in not pushed out!!!!! What is the diagnosis?

 

[rattana]

Re: New motor Won't Start

cam and crank are out of time.

 

[steve n carol]

Re: New motor Won't Start

hey, you're on to something! thought you were going to rest? "rolling" the crank key = pushing it out of it's seat as you install the crank harmonic balancer. the key has a curved bottom and so is the seat, thus "rolling" and push it out of the seat.<br />Sounds like a cam off time. Is this a NEW or different camshaft? is it for your engine? Fishmark sent you a diagram of the cylinder configuration and firing order, (I am assuming this is the correct one), Does yours match? (like are you on #1 cylinder)? does OMC time on the #1 cylinder? I am trying to lead you to checking simpler components/systems prior to pulling your timing cover and or camshaft. fix dinner for your friend!

 

[Sydmoe]

Re: New motor Won't Start

When i put the timing chain on #1 should have been at TDC right? Cause thats the way I did it. However, I remember after I put the timing chain and cover on that as i was reading my Seloc manual and I saw something about putting on a "Cam Thrust Plate" . It looks to hold the cam in place. I didn't remember removing such a plate but there where 2 holes on either side of the cam so maybe i did remove the plate and because it wasn't in my box of parts I thought I better get one and install it. I did and shortly there after realized that this plate must be used on some other motor config cause it wouldn't allow me to put the timing gear on so i discarded it. Now thinking back even though I am sure I lined up the marks when re-installing the chain and gear I am a little foggy on if the crank may have been moved one revolution and even though the marks were lined up #1 may not have been at TDC. This part of the assembly happened over a one week period.... Is it possible to install the timing chain and sprocket with the marks lined up but not have #1 at TDC. Would this cause my problem??????

 

[Sydmoe]

Re: New motor Won't Start

Steve,<br />The cam is new... not the original to the motor. It came in the rebuild kit and is specifically for marine use. Said so on the box.....Please tell me it is just inpropper installation of the timing gear and sprocket!!!!........that I can correct in the boat....if it is the cam, I am going to have to pull the whole motor again!!!!!!!Aughhhhh

 

[steve n carol]

Re: New motor Won't Start

Syd, you wrote, "Is it possible to install the timing chain and sprocket with the marks lined up but not have #1 at TDC. Would this cause my problem???" <br />yes this is possibile. <br />I am looking at the 350 ci merc timing chain and sprockets in my mercruiser manual. It's just like the ones in my truck. 4 holes in the cam gear. 1 is for a dowel, 3)are for the 3 bolts, 5/16"-18 that secure the gear to the camshaft. (I use loctite on these), the camshaft gear is positioned with the timing mark at the bottom, closest to the crank gear.<br />the CRANKSHAFT gear is installed with the timing mark to the TOP of the gear, closest to the camshaft gear. I don't recall if this is TDC for cyl #1, something tells me not, it dosen't matter at this point. There is another proceedure you may have overlooked.<br />When you installed the lifters. Are they hyd. or mechanical? Hyd. lifters usally have to be 'pumped' up with oil prior to installation. You did mention that you adjusted them 'dry'. I think you meant 'on the bench' or 'static', (w/o the engine running). Q) supposing these are Hyd lifters, and you 'pumped' them up, prior to assembly. Next dropped the pushrod in, and when you began to adjust the rocker/pushrod clearence, WAS the cam lobe, where it contacts the lifter, on the HIGH part or the LOW part? <br />same goes for the mechinacal lifter. (think about this). <br />** Now if these are Hyd lifters, and they needed to be 'pumped' up, and you didn't... then they will 'pump' themselves up and crowd the combustion chamber, not to mention no compression, but that another problem. let me know. get some sleep, go to work make lots of money tomorrow so you can work on your boats! ha ha. <br />PS. why do you have to pull the engine to pull the cam? sl

 

[Sydmoe]

Re: New motor Won't Start

PS. why do you have to pull the engine to pull the cam? sl

Because unless I drill a hole thru the wall of the aft cabin I don't have enough room to pull the cam forward to clear the motor and eningine bay bulkhead.<br /><br />I am going to pull the front of the motor apart (pulleys, water pump, timing cover etc.) tommorow after work. Forcast is good till Wed when we are suppose to get rain so I gotta get it done before then. This has to be my proplem.

 

[rattana]

Re: New motor Won't Start

Syd, it is totally possible to have put the cam shaft sprocket on when the #1 cylinder is not at top dead center, or any other senario to have it not mecahnically timed. It is easy to correct, you don't have to pull the cam. Remove the waterpump, and other stuff off the front of the motor. Crank the motor over to make the crank sprocket timing mark faces straight up. If the cam sprocket is not lined up then crank the engine crank one more revolution. If the cam doesn't line up in either of the 2 times the crank shaft mark faces upwards then you have to adjust the mechanical timing. Take the timing chain off to re adjust the mechanical timing. When the timing mark is on the top of the crank sprocket, the mark on the cam sprocket should be on the bottom of the cam sprocket. If they don't line up then turn the cam shaft to line up the two marks. If you use a straight edge, the center of the cam shaft, the mark on the cam sprocket, the mark on the crank shaft sprocket and the center of the crank shaft should all be in line. Next you put the timing chain on without turning anything. It will be mechanically timed.

 

[Sydmoe]

Re: New motor Won't Start

I can't get my head around how I would have screwed this up. If the marks (Cam at 6 and crank at 12) are lined up then how can I be out 180 deg. Essentially that is what I beleive I am out. When I stick my finger over the spark plug whole on what should be the compression stroke (both valve are closed) I feel suction. THis leads me to believe I am out 180 deg. Am I wrong on my assumption???

 

[llerrad]

Re: New motor Won't Start

Just a thought reading in your frustration. Time to step back, maybe take a trip to a local rebuild shop and just ask a question or two and maybe have one of the tech's show you and engine in rebuild.

 

[TwoBallScrewBall]

Re: New motor Won't Start

The cam sprocket can't go on wrong because it has a dowel. The crank sprocket can't go on wrong because it has a key (if I remember correctly). If you lined the dots up then you're set as far as mechanical timing. Is there any chance that the cam you installed is for a reverse-rotation engine? Only thing I can think of after all else you've tried here... kinda sounds like a possibility.

 

[rattana]

Re: New motor Won't Start

Syd, if the mark on the crank sprocket is coming up to TDC, #1 cylinder is coming up to TDC. The piston and crank are in essence one piece of metal. Once it goes past TDC it will start to suck your finger in the hole. It doesn't make sense that there is suction if the crank is coming up to TDC. I don't want to send you under a bus, but IMO first off you need to verify the crank and harmonic balancer relationship. Also see if there is any damage to the balancer. At mechanical TDC the timing mark on the harmonic balancer should be bang on TDC. If that checks out then double check the crank and crank sprocket assembly. Like Steve says, the key could have slipped out of either one on installation. Once you know that is right, the cam is the next thing to verify.

 

[Sydmoe]

Re: New motor Won't Start

I went out at lunch and bought a compression tester and went home to check it. No compresssion!!!! I suspect if i put a vacuum tester on i will get a reading!!!Could this be the result of a reverse rotation cam as Steve H suggests. I called the place I bought the rebuild kit which also included the new cam I installed. They claim the one they shipped me which is a Perfect Cirlcle brand is the correct cam and is not reverse rotation. Could this be the one in a million chances of the item in the box being different from what it is suppose to be. I do remember checking the numbers on the packing slip with the numbers on all the boxes because I was worried I didn't get the correct oversize bearings. All the numbers checked out. The Cam number on the box was 229 1879. I don't have anyhting to refer to other than what they say.<br /><br />Are things starting to point to the wrong cam???

 

[Sydmoe]

Re: New motor Won't Start

you guys give up on me!!!