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View Full Version : WHERES A GOOD PLACE TO BUY JETS???



Instigator
05-14-2001, 08:09 AM
Any suggestions on where to get jets for OMC loopers w/o getting raped?????
Thanx guys!

Ray Neudecker
05-14-2001, 03:20 PM
Visit salvage yards and dealer junkpiles. get a set of orfice drill bits from the local plumbing store and drill to what you want. I belive you want the D size.If they will screw in the hole you can make them work. You probably wont be able to get the size you need if you finger port that block. the largest they have is a 79. You will have to make them.

RocketMan
05-14-2001, 03:44 PM
I agree with Ray, however, you can improve accuracy by using a reamer instead of a drill bit for the final sizing. Buy number reamers from you local mill supply store the exact size(s) you want.

Use a drill bit that gets you close but .005-.010 inch smaller than the finished hole size you want. Put the reamer in your bench vise and turn the jet(s) slowly onto the reamer BY HAND! Use kerosene or cutting oil. After a little practice, finished jets will be perfectly round and accurately sized.

Paul

Instigator
05-14-2001, 04:45 PM
Do the numbers on the jets correspond to size in thousandths?? i.e. 79 = .079" ??
Ray, I think you're right on the "D" desigantion as well. In process of cleaning nuked piston out of my 250 Ocean Pro carbs and their jets are #75D, probably the same for my old looper. They look the same externally.

Ray Neudecker
05-14-2001, 06:52 PM
The number on the jets is in thousands. The reamer idea is the best way to go on final setup. You can buy what you know you will need for a finished product. i just drill up a few sizes at a time and can get close enough with the orfice drills. You can buy a complete set for about 80 bucks here. You have to buy the reamers one at a time.Most of the single barrel carbs use the D jet size. Good Luck.

fastbasser
05-14-2001, 07:50 PM
Gotta dissagree with some of the above comments.
1)I have 86s & alot of others..
2) It aint the drill size, it's the flow. I spent alot of time measuring mine. If you go drill size only, you are makin a mistake.

Got mine right from OMC..

Ray Neudecker
05-14-2001, 09:21 PM
They have never listed a D jet larger than an 80. for some reason only the 79's have been available for several years. I wouldn't be suprised if the old racing division or Second Effort had some in other sizes. It is also easy to stamp what you want on them.

fastbasser
05-16-2001, 07:07 PM
Ray,

No disrespect intended by this post. Mine came directly from OMC. Got them right out of the OMC envelopes with the part numbers attached. I have to add from an OMC School instructor that built my motor. (Performance Racing & Marine)

Like I said in the earlier post, I spent time checking them with machine shop drill bits. The high 70s to low 80s were close in diamiter. You can not use that as a gauge.

Like many guys, I learned most things the hard way. I do know these are factory jets though.

Vinnie

Instigator
05-16-2001, 10:02 PM
You lost me on the sizing???
You saying that you think they are numbered by drill # sizes??
Thanx,
Instigator

Ray Neudecker
05-17-2001, 09:10 AM
I said they didn't list them larger than 8o's in the parts books. There have always been parts the factory had that weren't available through the normal parts channels. I would have no reason to doubt what you say. But you can't go to the dealer today and order them. All factory jets are marked in thousands relating to the size. The ons we have drilled out are also marked in the same way. We simply use the same type stamp as they do and mark them. Ihave gotten some from specialty builders marked the same way. Whether they had a source at the factory I don't know. They may have done the same thing as we do now. The easiest souce ofreference on sizes is in every OMC V-6 manual. It gives the sizes in metric,standard and orfice drill bit number for a large number of sizes. The original question had to do with sourcing jets without paying the hefty prices for new ones from the dealer. I offered a suggestion based on my experience with this same problem. Whether it fits his needs or not is up to him. If you either can't or don't want to go to the dealer and pay the price asked if the part is available,then you have to come up with another method. This has worked for me. One size doesn't fit everyone. This forum is for people to share ideas which may help someone else.

Jay Smith
05-17-2001, 09:48 AM
Back MANY years ago whe I was messing with carbs on 2.4's I would soft solder (-5 pts sp ) up jets and ream them to the size I wanted ! If you gotta 2 heat gun just apply flux and sit the jet on the paddles on the gun and when she gets hot put a drop of solder on it wait till cool then vise it and ream to desired size. Thats before I got a lathe.

Good luck !

Jay @ JSRE

Instigator
05-17-2001, 12:12 PM
Both very good tips! Thanx again Ray for your continued support.
I think I've got a source for jets at a good price tracked down.
One of my new found OMC buddies down south has a box of them he's digging out for me. He keeps mumbling something like "you'll get tired of screwing the little bastards in and out and switch to injection like I did!" Hah, Hah!
P.S. Also has run a motor very similar to my project at over 325 HP's on the dyno!!!
Again I say, I might be on to something???

Liqui-Fly
05-17-2001, 02:35 PM
hehe. Couldn't resist. LF

fastbasser
05-17-2001, 08:01 PM
Ray,

The lesson I learned by the way is that jets that size are useless in all but extreme cases.My motor was real strong and needed jets no where near that size!

Once I increased my air intake, I ended up down in the high 70s..

Great debating with you.

Vinnie

racer
05-17-2001, 10:32 PM
Jets are currently available in sizes up to 81d the part numbers are in the service manuals. I check availability this am. I have a limited supply of jets up to 89D, factory made. Should you decide to make your own, It takes an 87 reamer to flow an 82D jet. With proper porting you should not need to go over an 83D, proper meaning your brake specifics are reasonable.

markt111
08-08-2007, 10:55 AM
I know this is an old topic... but why does it take an 87 reamer to flow an 82d jet?? does it need to be a tapered hole?

jphii
08-08-2007, 10:58 AM
The jets get washed out to a larger size after a while. Most of the guys I know all use drilled jets so they know EXACTLY the diameter of the jet. No taper.

Instigator
08-08-2007, 04:08 PM
I know this is an old topic... but why does it take an 87 reamer to flow an 82d jet?? does it need to be a tapered hole?

all the looper main jets are .0055" bigger than the number stamped on them.

An 80D is not .080" i.d. like most think, they are .0855" i.d. and yes there is a taper on the lead in causing a slight venturi effect.

That is why a true 80D will out flow a 75D reamed to that size. By reaming the 75 out you removed most if not all of the taper so your opening is now just a straight hole.

To jet accurately you have to be very carefull of what you're actually using.

Back to the above example, if you jetted 5 holes w/80's and ran out of jets and had to ream a 75 to 80 specs that hole would be lean if the motor was perfect w/a true 80.

Confusing but is real.

Look in the end of a virgin jet w/a magnifying glass and you can see the taper.

The OMC book even says 80D's are .080".

They are not and I have won many beers over that one ;)