QD 20 part numbers. Help. Joe? Hooty? Chine? JB? anyone?

motordummy

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you guys seem to be some of the omc guru's. chine, i believe you have several posts about a QD 19-appears that you may have rebuilt one. Anyway, from my prior posts, this is the motor that sunk. finally got my factory manual, parts catalog, etc. Broke the powerhead down. Innerds do not look too bad, but SOMETHING IS WRONG.<br />My manual lists th OE piston as 377043 but says it is the assembly. The other options for pistons oversize were 377024 (.020 oversize), 377037 (.040 0versizze), or 378285 (upgraded standard made after 1962). THE NUMBER ON THE ACTUAL PISTONS (BOTH) IS 377029. where did this come from??? did someone slap the wrong one in before and how could it work? sleeve is not scored at all-will check bore. pistons each have one area of vertical scoring that i can both see and feel with my finger-are they trashed? looks like scored against intake or exhaust opening in the cylinder.<br />one last question. i cannot get the upper crankshaft bearings off-the KEY will not come off the crankshaft to get the retainer/sping off. is there a TRICK to getting this woodruf key out?? thanks.
 

OBJ

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Re: QD 20 part numbers. Help. Joe? Hooty? Chine? JB? anyone?

Motor....what you are probably seeing is a supercede number. As improvements/changes are made to parts, the number is changed. So the original part number is superceded with a new part number.<br /><br />As far as the scoring, check the edges of the exhuast prots. Are they real sharp? If they are, this is probably what caused the scoring. The edges of the ports were not "broken" after honing or boring. The sharp edges can very easily scrap the alum piston and cause the damage you describe.<br /><br />Crank key, take a punch and put it to the flat side of the key and tap it towards the keyway. This should rock the key out of the keyway.<br /><br />Keep us posted...
 

motordummy

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Re: QD 20 part numbers. Help. Joe? Hooty? Chine? JB? anyone?

thanks, outboardjim. yes edges are sharp, how does one specifically unsharpen them before reassembly without damaging the sleeve? are the pistons now worthless?<br />regards upgrades numbers-the upgraded number was the one from 1962 unless they were again upgraded after that. now, parts do not pop up for these under wiseco or aftermarket piston manufacturers so i doubted that there was ever an upgraded new number for these. the upgraded 1962 came with needle bearings on the wrist pin. thnx.
 

Hooty

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Re: QD 20 part numbers. Help. Joe? Hooty? Chine? JB? anyone?

If you have to replace the pistons, I'd avoid forged pistons and stay with the cast ones. Personally, I like the Pro Marine pistons.<br /><br />c/6<br />Hooty
 

OBJ

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Re: QD 20 part numbers. Help. Joe? Hooty? Chine? JB? anyone?

You can break the edges with a small rattail file. Break them towards the outside of the sleeve just enough to cut away the sharp edge. Check that you don't leave any burrs behind.<br /><br />I'll have to check on the part numbers in the morning. Maybe Joe Reeves or one of the other guys will venture by and give ya' some info in the mean time.
 

motordummy

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Re: QD 20 part numbers. Help. Joe? Hooty? Chine? JB? anyone?

heres the skinny on all the innerds. journals, bearings, rollers,needles, races on rods all look surprisingly clean, pit, and rust free-there is a jagged circular scrape on the lower crankshaft journal but it is BELOW where the roller bearings ride, almost where the oil seal would be and not significant. i dont think. again i will check the bore. looks like the 99,000 answer is:<br /><br />will i need new pistons?? I AM HAPPY TO TRY TO EMAIL PIX IF HELPS. if needed, any sources?? i am thinking that the pistons i pulled with the noted number in original post MIGHT be the oem as my parts catalog says ASSEMBLY-anyone know? if they by chance are useable ok i would definitely need a ring set. again, sources?<br />also 2 new oil seals. updated number 302036<br />also 2 new o-rings. number 301967<br />also 1 new o-ring. number 302035<br />also 1 new gasket set. number 377827<br />also 1 new head gasket. number306174<br /><br />any of you longtimers have any of these and the pistons might be ok, pls let me know and i can put the poewrhead issue to rest-at least for the parts-would start askig about honing, cleaning out exhaust and water jackets, painting, etc later, and move to ignition and lower unit. thank you for all of the input thus far.
 

Hooty

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Re: QD 20 part numbers. Help. Joe? Hooty? Chine? JB? anyone?

Your best bet is gonna be taking or sending the block to an outboard machine shop and let them decided wither it needs boring or not. It's not just scored cylinder walls, it's a matter of roundness to. <br /><br />c/6<br />Hooty
 

alcan

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Re: QD 20 part numbers. Help. Joe? Hooty? Chine? JB? anyone?

Hi Motor <br /> The confusion with the piston part #'s seems to be between a piston assembly and a piston. The piston assembly is (in this case) a piston,wrist pin, wristpin keepers and rod. No rings. There is also the fact that many of these orignal parts #'s have be superceded. I've studied my parts catologs and Master parts book for the last hour and a half trying to find you a profound answer as to what piston is what. Man I have to admit I think I am more confused than you are. Any how, if your motor was just sunk and wasn't running at the time. Just put the thing back together with new seals and gaskets and call it good. This assumes it ran well before. Go ahead and measure the bore,pistons and rings, etc for wear. New rings may be a good idea if necessary. Of course do as Jim suggests about the ports. If your pistons are still in spec,use them. A little scuffing on the skirts won't hurt. Be sure the ring groves are clean and free of carbon. Measure the ring grove clearance and end gap. Also if you reuse already run parts, put them back in the same hole they came from.
 

alcan

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Re: QD 20 part numbers. Help. Joe? Hooty? Chine? JB? anyone?

Head gasket# 306174 superceds to # 308394 $10.<br /> gasketset #377827 $10.<br /> o-ring #302035 .50<br /> seals #302036 2@ $15.<br /> O-ring # 301967 2@ .50 <br /> These prices are just an estmate, they may be more or less, depending.
 

motordummy

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Re: QD 20 part numbers. Help. Joe? Hooty? Chine? JB? anyone?

thanks for the input guys. hooty, i planned on having bore and roundness and any honing/boring done by a shop-i certainly do not have the proper tools to do myself. being a winter project, time is not a constraint here. pls keep in mind that have never torn down an outboard and chose the username as "the phrase just fit". i am learning alot and you guys are a very valuable resource. thanks.<br />keeper of the cuervo??
 

Hooty

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Re: QD 20 part numbers. Help. Joe? Hooty? Chine? JB? anyone?

Si.<br /><br />c/6<br />Hooty
 

Chinewalker

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Re: QD 20 part numbers. Help. Joe? Hooty? Chine? JB? anyone?

The reason the number cast into the piston doesn't match the number in the parts book is that the number in the piston is a casting number, not the part number. It's likely the piston you have is fine, assuming there is no damage to it beyond the light scuffing you noted. The casting number is close enough to the part number that I am inclinded to believe it's the right one. I don't have a piston handy, or I'd check one for you...<br />- Scott
 

Joe Reeves

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Re: QD 20 part numbers. Help. Joe? Hooty? Chine? JB? anyone?

I really didn't think I had anything that would help but I checked my remaining inventory anyhow. For what it's worth, I have one brand new #378285 Piston and one #308394 Head Gasket left in stock.<br /><br />The price I see on the piston is $52.00, and on the gasket $16.50. If you can use them, both will go for a total of $38.00.... just a thought.
 

motordummy

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Re: QD 20 part numbers. Help. Joe? Hooty? Chine? JB? anyone?

thanks to all so far-hoping I'm not getting to be a PITA. My neighbor is a machinist and we checked cylinder measurements, upper and lower, top and bottom of each, 12:00 to 6:00 and 3:00 to 9:00-eight total measurements. manual states bore is 2.375". all measurements were within spec (2.3755") except the head end of the lower cylinder, measured crosswise 3:00-9:00 which was 2.3775. two one thousandsths off. do not see rebore as needed as spec is .003-.0035-it seems to be in pretty good shape. He doesnt have a ball hone so will have honed at local outboard repair shop with machining. Said will do for $20.<br /><br />Now, there is quite a bit of crud in the water jackets and do not know what is in the oil passages, heavy carbon on the exhaust, etc. In short, i would like to do this right and would like this whole powerhead cleaned up before going forward. How do i clean it good? Is it proper to soak this whole "assembly" in anything much like carb parts? or what is proper cleaning of the innerds-wouldnt assume that you just drop a block into a bucket of b-12 and soak it-or do you? but never done this-would guess that solvents may mean trouble? would like to get it all clean, then have honed, then wash in water and detergent to clean off any potential left over burring, then oil up all inner parts, and paint. any tips here?<br /><br />Regards painting, any tips? Bolt all back together, cover and tape up openings, crankshaft, etc and spray away?? certainly never done this. thanks for any tips. <br /><br />also, i would like to replace the lower piston if i can find a NOS cheap or a good condition one-old one on lower cylinder appears to have scored on a sharp port, maybe? The one Joe had in prior post will not work in my motor as it is for updated ones for after 1961 with wrist pin needle bearings my wrist pin has friction old bearings. new oil seals #302036 and new rings #301787. <br />--------------------------------------------------------------------------------
 

Hooty

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Re: QD 20 part numbers. Help. Joe? Hooty? Chine? JB? anyone?

After honing, wash the cylinders with hot water and Dawn Liquid Detergent. In fact, if you plan on painting it, wash the whole thing. Rinse with hot water and then oil the cylinders good to prevent rusting and reassemble.<br /><br />c/6<br />Hooty
 
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