New motor Won't Start

[Sydmoe]

Well after the guidance from many here I got my 1988 5.7 OMC out of the boat and rebuilt it over the last few months. I put it back in hooked everything up and have spent the last 2 days trying to get it to fire. I brought it up to TDC made sure the rotor was pointing to #1 on the cap and put in the distributor. I hooked up a timing light and i am getting spark. fuel seems to be there cause when i hit the throttle I can see it spray into the carb. I checked and re-checked and triple checked the firing order and it seems to be fine. I loosened the distributor and rotated it while the engine was turning over hoping to get it in a spot that would fire her up. No luck though. I changed the points, cond., rotor and even bought a brand new coil.......still nothing. The best I get is a little rumble type back fire thru the exhaust. I even pulled the distributor and rotated it 180 deg just because I was out of ideas. It backfired thru the carb so I know it was right the first time so I put it back. Sorry for the long post but I just want to give you the history of what I already checked. I took my time putting the motor together all tolerances, specs, and torque values were done by the book.<br /><br />The only thing I am second guessing, unless you guy can give me some other ideas, is if I properly timed the timing chain and sprocket. It was a Cloyes double roller and you had the option to advanced, retard or use factory specs. I am almost 100% sure I set it to the factory spec but with everything I have gone through trying to get this thing going I am reaching for all possibilities now. Even if I did install it with one of the other options, would rotaing the distributor bring it back in to timing?<br /><br />Has anyone gone through this and if so how did you get it going.<br /><br />Thanks again for taking the time to help a fella out!!!

 

[Sydmoe]

Re: New motor Won't Start

Question#1: When i am standing in front of the motor looking at the distributor and I have number 1 at TDC what postion should the rotor be in? Mine looks to be in the 5:30 pos. Not quite at 6:00. Is that correct?<br /><br />Question#2: What postition is number 1 plug suppose to be on the distributor cap in relation to the hold down screw. Would it not be in the 4:00 position? Thats what it looks like in my Seloc manual.<br /><br />For me to line up number one one the cap with the rotor I would have to rotate my distr. so as the hold down screes will be located in the front and rear of the motor.

 

[rattana]

Re: New motor Won't Start

When your #1 cylinder is at TDC on the compression stroke, the rotor has to point to the position where #1 wire is on your distributor cap. It is very posible that when you put the distributor back in after the rebuild it could be out a tooth or two causing the rotor to point in another position. You want the distributor installed so that you can easily adjust the timing. <br />You could pull your distributor and reinstall it to point in the direction that it shows in your manual at TDC.<br />Also is the cam shaft timed to the crank shaft? You want the valves to close at the proper time to get compression. There are timing marks that have to line up between them as well or it won't run.

 

[xltier]

Re: New motor Won't Start

is there any chance that u tightened the valves too tight.then there is no compression.5 oclock position is rite for #1 in the cap.then go clockwise looking fron the front of boat toward rear,1 8 4 3 6 5 7 2. 1 3 5 7 will be on your rite side[facing the motor].whats ur point gap.do u have good spark at the plug.just some thoughts.hth

 

[Sydmoe]

Re: New motor Won't Start

Maybe this will help with my description<br /><br /><br />

<br /><br /> javascript:openHiRes('http://www.clubphoto.com/memberservices/premium_pop/hi_res_download.php','compact_slide_show');

 

[Sydmoe]

Re: New motor Won't Start

sorry.....that link to some pics i took didn't really work like I thought. I will have to try and post them some other way.

 

[Sydmoe]

Re: New motor Won't Start

try going here<br /><br /> click here

 

[Sydmoe]

Re: New motor Won't Start

rattana <br /><br />One my motor (OMC 5.7 aka SBC 350) the distrib can't be out a tooth because the oil pump shaft drive is at the bottom of the distrib and it is a slot. The distrib won't fully seat to the intake if you are out a toooth or 2. You can however be out 180 deg. But I don't think i am as i have check several times today to see where the rotor was pointing at TDC. And your second point about the timing of the crank is something that maybe be my proplem but I really feel that I didn't miss lining up the marks when i put the timing gear and chain on.<br /><br />xltier <br /> <br />I thought of that too. I have backed off all valve lash so that i can easily spin the push rods with my fingers when the vales are closed. I bumped the motor and did each cylinder. Point gap as you asked was set to .018 per the manual.<br /><br />I still think the rotor position at TDC looks wrong.

 

[xltier]

Re: New motor Won't Start

take out the #1 spark plug and hold ur finger over the hole and crank it over till u feel compression starting to escape.then|the next time the timing marks on the balancer line up that is #1 compression,firing time.remove the distibutor cap,the rotor should be pointing to the #1 spark plug wire at the 5 oclock position.

 

[Fishermark]

Re: New motor Won't Start

Your distributor doesn't care where it is (12:00, 3:00, 6:00) as long as your rotor points to the #1 post on your cap. (As long as you have room to move the distributor in order to change the timing, then the exact position doesn't matter). Does that make sense? <br /><br />Just line your timing mark up to the proper setting, (8 degrees before top dead center? That's a guess), then line your rotor up so it points at #1. To get it more precise you can put an ohm meter on the wire coming from your distributor (with the power off), turn the distributor, and when your lose continuity that means the points just opened and the coil will fire.<br /><br />Also try wiping a business card through your points to clean them up of any lint, etc that may cause it not to fire.<br /><br />Actually my first thought was that you had it out 180 degrees, but you already tried correcting that.

 

[P.V.]

Re: New motor Won't Start

OK, remember this! 6 O'clock/5:50....... it has no bearing, really! As a reference, I always make a "scribe" mark on the dist. base and block so I can get it roughly back where it came out. Helps in having enough adjustment while turning the dist for timing.... But, the only thing that does matter is that at TDC. (the piston at it's top travel in the cylinder, which should match the TDC make on the harmonic balancer) the rotor matches a dist cap location that you've designated as #1, then follow rotation around the cap with the correct firing order! If the oil pump shaft slot is off, use a long screwdriver to rotate it slightly so the dist seats at the location you want it to! Again, it helps if you made marks prior to taking the whole thing off/apart, but no matter! Just figure out what seems to give you adjustment/rotating ability and go for it! I would do another thing or two also. Use a jumper wire and send 12 volts directly to the + terminal of the coil and disconnect the interrupter switches and module for now. Worry about that stuff after you get the motor running!!. Set the timing (you can crank the engine and check for 4 degrees or so) and get this thing running!!!

 

[Fishermark]

Re: New motor Won't Start

Sometimes a picture is worth a thousand words:<br /><br />

 

[Sydmoe]

Re: New motor Won't Start

I quadruple checked the TDC. I just came back in from outside. Since I am working alone I but a piece of the kids silly puddy in the number one hole ( on the boat that is!!) Don't worry i didn't jam it in i just plugged up the spark plug hole. I cranked the engine till i heard a POP. Then it only had to be bumped a little to get the marks to line up. I could spin both push rods freely so I am sure i have both valves closed. I checked the rotor position and it was just shy of 6:00. I pulled the wires off the dist. and started putting them in the firing order starting with number 1 from the location the rotor is pointing. Put the cap on and cranked her again....Still nothing...not even sputtering. I had the wife cranker it ( again I am talkin about the boat!!) and I used the timing light to see how far off I was from the 10 deg BTDC the book calls for. I am in the nieghborhood but it is hard to see it exactly cause the starter only spins the motors so fast as I am sure you can imagine. Still no life......

 

[Fishermark]

Re: New motor Won't Start

You say you have spark. Have you tried some starting fluid?

 

[Sydmoe]

Re: New motor Won't Start

Haven't tried starting fluid......but I know i am getting fuel...I can see it spray when i move the throttle and look in the carb. I may have the plugs all fowlled up with fuel from cranking it all day. I will let it sit tonight and try again in the morning i guess.......

 

[DJ]

Re: New motor Won't Start

If you are saying that the rotor was at 6:00, standing in front of the engine, I would say you are way late. The rotor should be just past 4:00. Or just past three, as a starting point. You have advance to work with.

 

[Sydmoe]

Re: New motor Won't Start

Thanks DJ....I thought I was way out on the #1 position.

 

[Sydmoe]

Re: New motor Won't Start

Could my timing gear be set advanced??? As I said earlier. The Cloyes set I bought had 3 possible setting. Advanced, retarded, and factory....I could swear I set it to factory but maybe I didn't. Could it be the source of my problem and if so how do I work around it.

 

[steve n carol]

Re: New motor Won't Start

syd, I agree with all of the above, however, you may want to wait on the starting fluid. you have ignition and fuel. turning the oil pump with a long screwdriver is good, if you need to, (probably do), in your pics I saw the rocker cover off, if you 'roll' your motor manualy, you can follow the compression strokes by watching the rockers go up...and down, intake, exaust,etc.<br />this coincides, (should) w/the firing order, you must turn your motor over the correct way, clockwise or counter clockwise. and again, should coincide with the pointer on the dist. As far as the cam timing... Could a DEGREE WHEEL be of use? (help from others) I am bringing this up because I have read that different marine manufactures utlize different firing orders on thier engines/cams/crankshafts, there are also C wise and CC wise engines. Sounds like your'e getting an education even if it is w/silly putty, (or was it play dough), now you can tell your kids that they helped! and will probably grow up to be great mechanics! Gotta fire extinguisher close? sl

 

[Fishingtime]

Re: New motor Won't Start

Hi Sydmoe,<br /><br />I have more than 35 years working as a mechanic. I would like to give you some basic ideas that might help. When the crank pulley is on top dead center it only tells you that #1 piston is at the top of its stroke weather it is exhaust or intake. First thing to do is disconnect the battery! Remove #1 spark plug, place crank pulley at TDC. If you insert a philips screwdriver into the spark plug hole you will feel the top of #1 piston. Gently rotate the engine clockwise about 2 inches then back to TDC and counter clockwise about the same distance. You should feel the piston move down in both directions with TDC being the highest point. If this is not the case then the crankshaft key may have slipped out on assembly or if the crank pulley has a rubber insert in it and has slipped it indicates that you need a new pulley. Next I would remove the timing cover and recheck the camshaft timing and set it at the factory setting. If cam is off even by one tooth it will cause the problem you are having. There are two types of timing which are Camshaft timing and ignition or distributor timing. It is possible to have perfect ignition timing while having cam timing off. Another thought is to run a compression check. If some cylinders are high and others are very low it would indicate the valves are adjusted to tight on the low cylinders. If all cylinders are low it would indicate that all valves are to tight or Camshaft timing is off. I hope this will be helpful. As far as your distributor, you should know that when you install it if it does not drop all the way down you can remove it and with a long screwdriver you can turn the oil pump shaft until the distributor will drop all the way down in the position you desire.