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OMC main jets have no ID number

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PhilSch

Regular Contributor
Going .040 over on rebuild and want to richen the mixture a couple of jet sizes. The main jets have no number on them. I do not have pin gauges to precisely measure the size of the hole; using a caliper it's close to .075 or .076. The factory manual shows the largest jet for 5/16th thread size is .070??

Does anyone know what the stock jet size is for a 1988 OMC 110 horse V4 crossflow?

For reference the intermediate jets are 25C and the high speed jets are 67C.

Do I need to change idle air jets also?
 
PhilSch said:
Going .040 over on rebuild and want to richen the mixture a couple of jet sizes. The main jets have no number on them. I do not have pin gauges to precisely measure the size of the hole; using a caliper it's close to .075 or .076. The factory manual shows the largest jet for 5/16th thread size is .070??

Does anyone know what the stock jet size is for a 1988 OMC 110 horse V4 crossflow?

For reference the intermediate jets are 25C and the high speed jets are 67C.

Do I need to change idle air jets also?
Click to expand...
The hi speed jet is .067 intermediate jet is .025 change hi speed jet to .069 (69c) I will get back to you with that part number.
 
I think the previous owner must have drilled the main jet (now .076) since the max spec listed in the manual is listed at 0.70. If that is indeed the case then I would not need a larger MJ and in fact may need a smaller one. Are there specs listed for specific engines anywhere? I find it interesting that jetting information is not in the factory manual.

My engine is J110TLCCA. High speed Jets are .067, intermediate jets are .025 and idle air jets are .036

If any of you have access to what the stock jet sizes are I would most appreciate it.
 
I had brain fog this AM when I took apart the carb. I unscrewed the seat under the float needle and mindlessly thought it was the main jet which is ridiculous of course but I was just not thinking clearly. It's hell getting old! Thanks for getting me that information guys.
 
Pappy, would you size up the intermediate jets and size down the air jet to to begin with? After checking on the parts list on this site I have confirmed my jets are all stock.

Thanks
 
If motor is tight and leak free..shouldn't have to change idle ..may have to drop 1 size on intermediate but run it first to see.
 
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