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mjb100798
07-26-2009, 08:47 PM
Hey guys great website, am a newby to the ski boat world, but not to motors in general. I have a 1989 prostar 190 that i just bought with what i believe is a 351 indmar....well heres the issue, got the boat home and could pull and start fine but when it came to WOT for more than 20 secs motor would start backfiring, well I thought it was a carb problem so had that rebuilt....no help, the boat mechanic couldn't or didn't have the time to fix it right away...long story short I started checking it out and someone had put a car MSD distributor and ignition box and coil on it...so i decided to go ahead and replace it with a mallory distributor, now comes the fun part, i cant get the engine to run right once it's in gear... i think either the firing order is all screwed up...

Does anyone know what the correct firing order is for this dang thing, i've looked on the intake and their isnt one stamped there so im not sure its the original... not sure how much longer this engine will last without a rebuild........

thanks in advance for you guys help....

TMCNo1
07-26-2009, 09:51 PM
Hey guys great website, am a newby to the ski boat world, but not to motors in general. I have a 1989 prostar 190 that i just bought with what i believe is a 351 indmar....well heres the issue, got the boat home and could pull and start fine but when it came to WOT for more than 20 secs motor would start backfiring, well I thought it was a carb problem so had that rebuilt....no help, the boat mechanic couldn't or didn't have the time to fix it right away...long story short I started checking it out and someone had put a car MSD distributor and ignition box and coil on it...so i decided to go ahead and replace it with a mallory distributor, now comes the fun part, i cant get the engine to run right once it's in gear... i think either the firing order is all screwed up...

Does anyone know what the correct firing order is for this dang thing, i've looked on the intake and their isnt one stamped there so im not sure its the original... not sure how much longer this engine will last without a rebuild........

thanks in advance for you guys help....
Here you go,
49782

mjb100798
07-27-2009, 07:07 AM
Thanks, that what i think it is as well, but need to know if thats correct for a righthand turning engine, also where did that diagram come from? We tried that firing order and couldn't get the motor to idle unless it was at 1500 rpm, currently the engine is running on the 1-8-4-5-6-2-7-3 which comes directly from the PCM manual for a right hand turning engine, I know im running a indmar but how much different can they be? i'm thouroughly confused on this issue, dont know which way to go.....

etduc
07-27-2009, 08:31 AM
Harold, posted the correct firing order. Indmar is a martinized Ford 351, uses standard 351 firing order. You're probably, one plug off. Comfirm top dead center, of the number 1 cylinder, start over.

TMCNo1
07-27-2009, 08:43 AM
Thanks, that what i think it is as well, but need to know if thats correct for a righthand turning engine, also where did that diagram come from? We tried that firing order and couldn't get the motor to idle unless it was at 1500 rpm, currently the engine is running on the 1-8-4-5-6-2-7-3 which comes directly from the PCM manual for a right hand turning engine, I know im running a indmar but how much different can they be? i'm thouroughly confused on this issue, dont know which way to go.....

The picture is for a 351W LH rotation Ford Indmar (black painted engine) that is the correct firing order, same as our '89 351W. Engine rotation should be rotating counterclockwise while sitting in the drivers seat, looking forward, also if the prop has LH stamped on it, it will be a LH engine rotation. RH rotating 302's and 351's engines were used`by PCM and some others in the late '60's and '70's IIRC.
As shown on the picture, it came from CarMemories.com that someone else had posted that I bookmarked for reference.

Read the numbers on the wires, follow the wires, I'm outta here.
Starboard side,
49787
49788
Port side,
49789
49790

Jayc
07-27-2009, 10:36 AM
1-8-4-5-6-2-7-3 is for a reverse rotation engine fitted into a nautique.

mjb100798
07-27-2009, 01:25 PM
Again thanks for replying guys, I've got the wrong firing order setup, I did try the firing order of 13726548, but couldn't get the engine to idle, it runs/idles on the 18456273 firing order, can someone please explain how to find TDC and also what mark should the balancer be on.. Thanks again for all the great advice...

TMCNo1
07-27-2009, 01:34 PM
Again thanks for replying guys, I've got the wrong firing order setup, I did try the firing order of 13726548, but couldn't get the engine to idle, it runs/idles on the 18456273 firing order, can someone please explain how to find TDC and also what mark should the balancer be on.. Thanks again for all the great advice...

Photo for reference, timing should be set @ 6 degrees BTC (3rd short mark down from 0) @ 600rpm in gear at ilde speed in the water. Marking the 6 degree line on the harmonic balancer with a White Out pen or something will help before you start.
49817

This is a very informative thread concerning the subject, http://www.mastercraft.com/teamtalk/showthread.php?t=31287&highlight=DeAD+cENTER

mjb100798
07-27-2009, 04:51 PM
You guys rock, thanks for the quick replies and photos... I'll try and set it up on the boat this afternoon and let you guys know how it goes.... again thanks a million for the info...

mjb100798
07-28-2009, 06:10 AM
Well, got the boat running initially then forgot to hook up water, so turned the engine off quickly and couldn't get it restarted mainly due to the battery dying on me, so will charge it up tonight and see tomorrow.... Is there anything special you have to do with the distributor other than know where its pointing at TDC, i mean does it have to be pointing at the #1 cylinder(mine points pretty much right at the carb) in order for it run right? Also do you have to be on the water to get the boat timed correctly, does it need to be under a load or at idle speed. Thanks for everyones helpful comments and pictures...

mjb100798
07-28-2009, 04:31 PM
Update.... got it running but the timing is way off, cant get it anywhere near the 6*, can you clarify the sitting in the drivers seat you said engine should rotate ccw, was that if i looked back at it, mine rotates cw if im looking straight at it from front to back of boat....also checked the propeller and it has LH stamped on it....i'm thouroghly confused about this stupid engine.... any help would be greatly appreciated... i got it started today w/ the 137 firing order but couldn't get the engine timed whatsoever....ran it two days ago with the 1-8 firing order and it timed ok, but sounded rough, pulled the plugs and 8,5,3 were still wet with fuel...any ideas why? thanks in advance...also i do have a topdown picture of the old distributor but i cant confirm which firing order is set...

JimN
07-28-2009, 04:47 PM
Update.... got it running but the timing is way off, cant get it anywhere near the 6*, can you clarify the sitting in the drivers seat you said engine should rotate ccw, was that if i looked back at it, mine rotates cw if im looking straight at it from front to back of boat....also checked the propeller and it has LH stamped on it....i'm thouroghly confused about this stupid engine.... any help would be greatly appreciated... i got it started today w/ the 137 firing order but couldn't get the engine timed whatsoever....ran it two days ago with the 1-8 firing order and it timed ok, but sounded rough, pulled the plugs and 8,5,3 were still wet with fuel...any ideas why? thanks in advance...also i do have a topdown picture of the old distributor but i cant confirm which firing order is set...

Look at the crank pulley to see which way it turns (CW) and don't worry about prop rotation when you think of this. Use the numbers cast into the intake manifold for your firing order.

Remember- the crank revolves twice for one distributor revolution.

Did you do a compression test yet?

Your firing order is 1-3-7-2-6-5-4-8. Remember, one cylinder bank is 1-2-3-4 and the other is 5-6-7-8, unlike a GM, which alternates. Before starting to adjust the timing, remove the cap so you're sure which way it rotates (this will tell you which way to turn it for increasing or decreasing the advance).

You posted that you have a hard time knowing when it's at TDC. Look into the oil filler hole and if you can see the #1 cylinder's valves, it will be easy but if you can't, loosen the valve cover so you can see under it. Remove the plugs and crank it over manually, using a ratchet wrench on the crank pulley bolt, turning it in its normal direction. Look at the exhaust manifold's port- one valve will line up with it and the other won't. ONLY WATCH THE INTAKE VALVE, WHICH DOESN'T LINE UP WITH THE EXHAUST PORT.

Step 1- Watch the intake valve open and close.

Step 2- Turn the crank CW until it reaches TDC after the intake valve closes. This is where you want to get the distributor to line up with a plug wire. If it's not the #1 plug wire, move the wires so it is, then verify that you have the wires in the right firing order, in the right direction.

Step 3- Snug the distributor hold-down enough that it won't move but you can still turn it. Mark the distributor's position on the intake manifold and don't worry about the plug wires yet.

Step 4- Turn the key ON and, with the timing light pickup on the wire that lines up with the #1 plug wire, rotate the crank forward and back about 10 degrees. The timing light should flash. You may want to tape the trigger button down so you have both hands free.

Step 5- Move the crank past TDC by about 45 degrees- rotate the distributor a bit toward the #8 plug wire and, aiming the timing light at the timing mark, turn the crank back to TDC. You should see the timing light flash closer to 6 degrees BTDC but if it flashes on hte ETC side, rotate it back and go past your reference mark at the base. If it's close, snug the hold down.

Step 6- turn the key OFF.

Step 7- Put the plugs back in, MARK THE #1 POSITION ON THE CAP AND BOTH PLUG WIRE BOOTS and if you want, an arrow on the cap to indicate the rotor's direction.

Step 8- Put the plug wires on in the correct order and crank it. It should start immediately and run smoothly.

mjb100798
07-29-2009, 07:56 PM
It appears i have one of the oddball 351's cuz by chance the guys at skimdim told me to call the local ford dealership and ask them what the firing order for an 351 from 89 for a car was and it's 1-5-4-2-6-3-7-8.... well as soon as i turned the key it pretty much started right up...got it timed to 6 deg TDC and its purring like a lion.....just have to put it in the water... can anyone clue me in as to why my engine would have this firing order? Also i will probably have to replace the power valve in the holley carb due to the multiple backfires with the other firing orders i've tried...hopefully this will be the last piece of the puzzle...

Thanks again to everyone who gave advice/pictures i really appreciate how quick everyone was to try and help with the problem...:D

JimN
07-29-2009, 08:18 PM
It appears i have one of the oddball 351's cuz by chance the guys at skimdim told me to call the local ford dealership and ask them what the firing order for an 351 from 89 for a car was and it's 1-5-4-2-6-3-7-8.... well as soon as i turned the key it pretty much started right up...got it timed to 6 deg TDC and its purring like a lion.....just have to put it in the water... can anyone clue me in as to why my engine would have this firing order? Also i will probably have to replace the power valve in the holley carb due to the multiple backfires with the other firing orders i've tried...hopefully this will be the last piece of the puzzle...

Thanks again to everyone who gave advice/pictures i really appreciate how quick everyone was to try and help with the problem...:D

Look on the intake manifold for a series of eight numbers and post them here, OK?

mjb100798
07-29-2009, 09:22 PM
E6TE-9425-CB, cant hardly make out the last two digits but i beleive thats what they are...

JimN
07-30-2009, 09:18 AM
E6TE-9425-CB, cant hardly make out the last two digits but i beleive thats what they are...

Is that the original manifold? Usually, the firing order is cast into it.

mjb100798
07-30-2009, 06:21 PM
Not sure, but there is definitely no firing order on it anywhere...I took the boat out today and it will pull up slowly, but if i try and throttle too much it wants to bog down, i probably blew the stupid power valve out....plus something is running the battery down or my starter is going out...boat doesnt want to start up after shutting down, battery seems weak and will barely turn the motor over, its brand new....volts show around 14 when boat is running but is there a way check whether or not the alternator is actually charging the battery when the motor is running...fix one problem and two more arise...man BOAT really does men Break Out Another Thousand....arggggggggghhhhhhh....

JimN
07-30-2009, 07:45 PM
Not sure, but there is definitely no firing order on it anywhere...I took the boat out today and it will pull up slowly, but if i try and throttle too much it wants to bog down, i probably blew the stupid power valve out....plus something is running the battery down or my starter is going out...boat doesnt want to start up after shutting down, battery seems weak and will barely turn the motor over, its brand new....volts show around 14 when boat is running but is there a way check whether or not the alternator is actually charging the battery when the motor is running...fix one problem and two more arise...man BOAT really does men Break Out Another Thousand....arggggggggghhhhhhh....

Check the voltage at rest and compare it to when it's running. If it's higher when running, the alternator is putting out voltage. However, it may have a bad rectifier and if that's shorted, it will discharge the battery is a few days. You can check for this with a multi-meter set to Amps by disconnecting one of the battery cables, connecting one meter lead to the battery post and the other lead to the battery cable. If you see about 300mA of current draw, the alternator needs work. You can also check this with a bulb-style test light (not the LED kind- they light up because of voltage and won't indicate current) by connecting it the same way. You would need to make sure none of the accessories are drawing current and the key has to be OFF for either test.

mjb100798
07-31-2009, 06:20 AM
when i turn the key on its always shown around 11.5 and when running its a steady 14, will try the battery test this afternoon, JimN you got any more ideas as to why my firing order would be so different than what everyone else seems to be running, could the previous owner have put an auto style cam in the engine?

JimN
07-31-2009, 07:25 AM
when i turn the key on its always shown around 11.5 and when running its a steady 14, will try the battery test this afternoon, JimN you got any more ideas as to why my firing order would be so different than what everyone else seems to be running, could the previous owner have put an auto style cam in the engine?

If it shows 11.5V, where are you measuring this- on the battery posts, at the starter or on the dash gauge? That battery posts is where all voltages are referenced. 11.5V is low for a charged battery, so I would check the battery terminals, check for resistance on the battery cables, make sure the ground point on the motor is clean and tight. If this is on the gauge, it could just be dirty terminals. The fact that the voltage goes to 14 while it's running tells me that the alternator is OK but the battery may have a bad cell or the charging lead may be bad, even though it may look fine.

Is there any way for you to get complete service information about this motor? You said that when the motor runs, the crank turns clockwise when you look from the front of the motor, right?

If you really have doubts about whether the cam is right or wrong, the easiest way to determine this (IMO) is to remove the valve covers and turn the crank manually, so you can watch the valves open and close. Once that's done, you would need to determine whether the crankshaft is correct and this is where knowing hte motor's history is important. If the motor looks like the paint on it is original, it probably is and it would mean that the cam and crank are original, too.

Have you checked the compression and vacuum?

mjb100798
07-31-2009, 12:41 PM
Im referencing the volt gauge for the #'s havent checked the battery but its brand new...and been charged since buying it...I will check the battery voltages today and let you know... as far as the engine is concerned the paint still looks original, but i know it's had some sort of work done on it cuz the manifold bolts are steel and look fairly new except for one which is still painted black like the manifold...i didn't do a compression check, but the mechanic that i took it too said all the cylinders showed 125...but he also rebuilt my carb and its still not right...i'm ready to just purchase a new carb....as for the battery issue it could be the wiring but i havent dug into that area yet....thanks for all your help...much preciated!!!

JimN
07-31-2009, 02:38 PM
Im referencing the volt gauge for the #'s havent checked the battery but its brand new...and been charged since buying it...I will check the battery voltages today and let you know... as far as the engine is concerned the paint still looks original, but i know it's had some sort of work done on it cuz the manifold bolts are steel and look fairly new except for one which is still painted black like the manifold...i didn't do a compression check, but the mechanic that i took it too said all the cylinders showed 125...but he also rebuilt my carb and its still not right...i'm ready to just purchase a new carb....as for the battery issue it could be the wiring but i havent dug into that area yet....thanks for all your help...much preciated!!!

Exhaust or intake manifold bolts? Do a vacuum and compression test. If the intake has been removed, it may have a leak somewhere and it will do just what you described. If it has a vacuum leak, it may be slight and it may OK at times but setting idle will be a PITA. 125 is a bit low unless it was checked cold. This needs to be checked at normal operating temperature with all of thhe spark plugs out.

mjb100798
08-03-2009, 12:25 PM
Well took it to the lake to test, boat ran ok, but not great...got rid of the power loss at WOT, but i have to ease her throttle...cant go WOT w/out it wanting to bog down...doesnt matter when i try to give it throttle, from sitting still or cruising at 25mph if i give it too much throttle it just wants to bog, unless i ease into it...

Haven't done the compression check yet...I tore into the dash to try and find out what the previous owner had done in there and it was a mess...once thats put back together I'll have to do the compression check...

JimN
08-03-2009, 12:36 PM
Well took it to the lake to test, boat ran ok, but not great...got rid of the power loss at WOT, but i have to ease her throttle...cant go WOT w/out it wanting to bog down...doesnt matter when i try to give it throttle, from sitting still or cruising at 25mph if i give it too much throttle it just wants to bog, unless i ease into it...

Haven't done the compression check yet...I tore into the dash to try and find out what the previous owner had done in there and it was a mess...once that's put back together I'll have to do the compression check...

If you can find a safe way to add gas while you try hard acceleration, that may indicate which way the air/fuel mixture needs to go.

Any backfiring or popping on hard acceleration or deceleration?

mjb100798
08-03-2009, 12:54 PM
Im thinking i blew the power valve out when i took it out before w/ the wrong firing order when it was backfiring quite a bit, but not real hard.... when i took it out the other day it was only backfiring on acceleration, but only when i tried to lay into the throttle, it was running great as long as i eased into the throttle, thanks again for all your help..

JimN
08-03-2009, 01:08 PM
Im thinking i blew the power valve out when i took it out before w/ the wrong firing order when it was backfiring quite a bit, but not real hard.... when i took it out the other day it was only backfiring on acceleration, but only when i tried to lay into the throttle, it was running great as long as i eased into the throttle, thanks again for all your help..

Was it popping through the intake, or exhaust? If it was only through the exhaust, I doubt the power valve has a problem and I would also doubt it if the throttle was open.

If you think about it, backfiring or popping is only happening when spark occurs at the wrong time or enough combustible gas is in contact with enough heat for it to burn. If there's enough valve overlap, it makes this more likely and some overlap is common.

Maybe it's a little on the rich side.

mjb100798
08-03-2009, 02:08 PM
Its backfiring through the intake and not the exhaust.... I still dont understand why my firing order is 1542... when everyone else is telling me its 137... there is no firing order stamped on the intake manifold except for what i've already posted...

Thanks

JimN
08-03-2009, 03:52 PM
Its backfiring through the intake and not the exhaust.... I still dont understand why my firing order is 1542... when everyone else is telling me its 137... there is no firing order stamped on the intake manifold except for what i've already posted...

Thanks

As I think I posted before, I think it may be time to verify the firing order but watching the valves. The odd firing order is unlikely if it's really a marine motor and it was original to the boat. Look on the valve covers for an Indmar sticker, or for a paper label on the oil pan. If it has one on the pan and it has an IF89xxxx number, it should be original to the motor. If it is, it may have gotten a new intake manifold, in which case I would want to know exactly what I was dealing with, if it was my boat.

Timing the motor when it might be one of three versions doesn't allow anyone to be sure it's correct.

etduc
08-03-2009, 04:54 PM
Its backfiring through the intake and not the exhaust.... I still dont understand why my firing order is 1542... when everyone else is telling me its 137... there is no firing order stamped on the intake manifold except for what i've already posted...

Thanks

I had a 1990 Tristar. This is the correct firing order.

http://www.boxwrench.net/specs/ford_302_351W.htm

Pre 1970 Fords 289, 428,427, etc had different firing order. Take note, there was a 302ex Ho engine (same vintage), that also used the older firing order.

I have learn on this forum. JimN knows, his stuff.

katmat
08-03-2009, 05:48 PM
By chance does your engine have points? If so make sure they are the correct points. I had a problem w/ a 1988 mastercraft w/ a 351w. The points I installed didn't have strong enough spring tension. It would run great up to 1900 rpm's & then would flatten out. It turned out that the points would "float" over 1900 rpm's.
Matt Murphy

TMCNo1
08-03-2009, 06:24 PM
All the more reason to install a EI/Breakerless conversion kit, http://www.skidim.com/prodinfo.asp?number=RP173071

JimN
08-03-2009, 06:42 PM
Did we talk about the advance springs and weights, yet? What about the timing mark when using the timing light- does it float or is it stable?

mjb100798
08-03-2009, 07:53 PM
I changed it to the mallory distributor from skidim, and it does have the old stickers on the valve covers, well i assume they were indmar ones but all thats left of them is the old residue, but its got indmar stamped on the small triangular piece for the water pump...by chance is there any quick way to determine the engine size? i've tried looking up the numbers on the bell housing but have had no luck...cant find any on the actual block, but their are some on the engine mounts... back to the firing order, Jim you said I should verify the valve position, but i guess i dont understand how it wouldn't time right with the 137 F.O. if it was correct, when i tried that FO, i couldn't even get it close to 6 degrees, at best it would idle at 22 degrees, but even then i would have to keep it rev'd to about 1000rpm... on the other hand with the 1542 FO it fired right up and timed to 6 degrees w/ no problems... I beleive you know your stuff about these boats, i'm so confused about this issue...i wish they had carfax's for boats...

JimN
08-03-2009, 11:27 PM
I changed it to the mallory distributor from skidim, and it does have the old stickers on the valve covers, well i assume they were indmar ones but all thats left of them is the old residue, but its got indmar stamped on the small triangular piece for the water pump...by chance is there any quick way to determine the engine size? i've tried looking up the numbers on the bell housing but have had no luck...cant find any on the actual block, but their are some on the engine mounts... back to the firing order, Jim you said I should verify the valve position, but i guess i dont understand how it wouldn't time right with the 137 F.O. if it was correct, when i tried that FO, i couldn't even get it close to 6 degrees, at best it would idle at 22 degrees, but even then i would have to keep it rev'd to about 1000rpm... on the other hand with the 1542 FO it fired right up and timed to 6 degrees w/ no problems... I beleive you know your stuff about these boats, i'm so confused about this issue...i wish they had carfax's for boats...

How well it runs with the wrong firing order depends on how many cylinders are affected and where their pistons/valves are supposed to be at the time.

IF the motor is still the original that came with the boat, MC should have a record of which motor you have. The hull number will tell them what they need to know.

"Jim you said I should verify the valve position, but i guess i dont understand how it wouldn't time right with the 137 F.O. if it was correct, when i tried that FO, i couldn't even get it close to 6 degrees, at best it would idle at 22 degrees, but even then i would have to keep it rev'd to about 1000rpm..."

This tells me that the firing order wasn't right. The #1 plug wire won't change but when you have cylinders working against others, it definitely won't run well at normal spec.

Have the compression and vacuum been tested?
What major service work has been done to this motor, to your knowledge? (I don't mean "I think", either)
Is there a way to contact the previous owner, and will they answer your questions honestly?