Carburetor jet increase question

[Slimm]

When going up 1 in jets, do you go up numerically to the next number or does going up 1 mean go up the next jet size? I've read and talked myself into retardation tonight and now I've cornfused and crossthreaded myself!

I think going up 1 means the next biggest jet because sometimes there is no next number up jet.
EX: going from an .082 up one size would be go to .084 since there is no .083.

Sometime toss me a lifeline please


Slimm

[Slimm]

Also, does anyone know of a chart that gives the orifice diameter of jets?

Slimm

[58Evinrude]

Yup, you are right. Going up one means going to the next size bigger. I don't know about the black motors, but with OMC stuff the jet number is the jet size.

[FORBESAUTO]

That's correct the size is the thousandths of an inch of the oriface. They come in .002 increments. Your thinking is exactly correct.

[vnemous]

I dont know if this helps Scott

[Slimm]

Thanks for all the help guys, YES Mike that is EXACTLY what I was looking for.


Slimm

[HStream1]

http://www.jetsrus.com/FAQs/FAQ_dril...uivalents.html

DRILL SIZE DECIMAL EQUIVALENTS

Drill size	Diameter (in)	Diameter (mm)
#107	0.0019	0.0483
0.05 mm	0.002	0.05
#106	0.0023	0.0584
#105	0.0027	0.0686
#104	0.0031	0.0787
#103	0.0035	0.0889
#102	0.0039	0.0991
0.1 mm	0.0039	0.1
#101	0.0043	0.1092
#100	0.0047	0.1194
#99	0.0051	0.1295
#98	0.0055	0.1397
#97	0.0059	0.1499
#96	0.0063	0.16
#95	0.0067	0.1702
#94	0.0071	0.1803
#93	0.0075	0.1905
0.2 mm	0.0079	0.2
#92	0.0079	0.2007
#91	0.0083	0.2108
#90	0.0087	0.221
#89	0.0091	0.2311
#88	0.0095	0.2413
#87	0.01	0.254
#86	0.0105	0.2667
#85	0.011	0.2794
#84	0.0115	0.2921
0.3 mm	0.0118	0.3
#83	0.012	0.3048
#82	0.0125	0.3175
#81	0.013	0.3302
#80	0.0135	0.3429
#79	0.0145	0.368
1/64 in	0.0156	0.3969
0.4 mm	0.0158	0.4
#78	0.016	0.4064
#77	0.018	0.4572
0.5 mm	0.0197	0.5
#76	0.02	0.508
#75	0.021	0.5334
#74	0.0225	0.5715
0.6 mm	0.0236	0.6
#73	0.024	0.6096
#72	0.025	0.635
#71	0.026	0.6604
0.7 mm	0.0276	0.7
#70	0.028	0.7112
#69	0.0292	0.7417
#68	0.031	0.7874
1/32 in	0.0313	0.7938
0.8 mm	0.0315	0.8
#67	0.032	0.8128
#66	0.033	0.8382
#65	0.035	0.889
0.9 mm	0.0354	0.9
#64	0.036	0.9144
#63	0.037	0.9398
#62	0.038	0.9652
#61	0.039	0.9906
1 mm	0.0394	1
#60	0.04	1.016
#59	0.041	1.0414
#58	0.042	1.0668
#57	0.043	1.0922
1.1 mm	0.0433	1.1
#56	0.0465	1.1811
3/64 in	0.0469	1.1906
1.2 mm	0.0472	1.2
1.3 mm	0.0512	1.3
#55	0.052	1.3208
#54	0.055	1.397
1.4 mm	0.0551	1.4
1.5 mm	0.0591	1.5
#53	0.0595	1.5113
1/16 in	0.0625	1.5875
1.6 mm	0.063	1.6
#52	0.0635	1.6129
1.7 mm	0.0669	1.7
#51	0.067	1.7018
#50	0.07	1.778
1.8 mm	0.0709	1.8
#49	0.073	1.8542
1.9 mm	0.0748	1.9
#48	0.076	1.9304
5/64 in	0.0781	1.9844
#47	0.0785	1.9939
2 mm	0.0787	2
#46	0.081	2.0574
#45	0.082	2.0828
2.1 mm	0.0827	2.1
#44	0.086	2.1844
2.2 mm	0.0866	2.2
#43	0.089	2.2606
2.3 mm	0.0906	2.3
#42	0.0935	2.3749
3/32 in	0.0938	2.3813
2.4 mm	0.0945	2.4
#41	0.096	2.4384
#40	0.098	2.4892
2.5 mm	0.0984	2.5
#39	0.0995	2.5273
#38	0.1015	2.5781
2.6 mm	0.1024	2.6
#37	0.104	2.6416
2.7 mm	0.1063	2.7
#36	0.1065	2.7051
7/64 in	0.1094	2.7781
#35	0.11	2.794
2.8 mm	0.1102	2.8
#34	0.111	2.8194
#33	0.113	2.8702
2.9 mm	0.1142	2.9
#32	0.116	2.9464
3 mm	0.1181	3
#31	0.12	3.048
3.1 mm	0.1221	3.1
1/8 in	0.125	3.175
3.2 mm	0.126	3.2
#30	0.1285	3.2639
3.3 mm	0.1299	3.3
3.4 mm	0.1339	3.4
#29	0.136	3.4544
3.5 mm	0.1378	3.5
#28	0.1405	3.5687
9/64 in	0.1406	3.5719
3.6 mm	0.1417	3.6
#27	0.144	3.6576
3.7 mm	0.1457	3.7
#26	0.147	3.7338
#25	0.1495	3.7973
3.8 mm	0.1496	3.8
#24	0.152	3.8608
3.9 mm	0.1535	3.9
#23	0.154	3.9116
5/32 in	0.1563	3.9688
#22	0.157	3.9878
4 mm	0.1575	4
#21	0.159	4.0386
#20	0.161	4.0894
4.1 mm	0.1614	4.1
4.2 mm	0.1654	4.2
#19	0.166	4.2164
4.3 mm	0.1693	4.3
#18	0.1695	4.3053
11/64 in	0.1719	4.3656
#17	0.173	4.3942
4.4 mm	0.1732	4.4
#16	0.177	4.4958
4.5 mm	0.1772	4.5
#15	0.18	4.572
4.6 mm	0.1811	4.6
#14	0.182	4.6228
#13	0.185	4.699
4.7 mm	0.185	4.7
3/16 in	0.1875	4.7625
4.8 mm	0.189	4.8
#12	0.189	4.8006
#11	0.191	4.8514
4.9 mm	0.1929	4.9
#10	0.1935	4.9149
#9	0.196	4.9784
5 mm	0.1969	5
#8	0.199	5.0546
5.1 mm	0.2008	5.1

[Slimm]

WoW Bud, that's some detailed info right there!
You amaze me with the info you have at hand at any given time, you must have been around a long time or been elbow deep in lots of hobbies over the years. Thank you buddy.


Slimm

http://www.jetsrus.com/FAQs/FAQ_dril...uivalents.html

DRILL SIZE DECIMAL EQUIVALENTS

Drill size	Diameter (in)	Diameter (mm)
#107	0.0019	0.0483
0.05 mm	0.002	0.05
#106	0.0023	0.0584
#105	0.0027	0.0686
#104	0.0031	0.0787
#103	0.0035	0.0889
#102	0.0039	0.0991
0.1 mm	0.0039	0.1
#101	0.0043	0.1092
#100	0.0047	0.1194
#99	0.0051	0.1295
#98	0.0055	0.1397
#97	0.0059	0.1499
#96	0.0063	0.16
#95	0.0067	0.1702
#94	0.0071	0.1803
#93	0.0075	0.1905
0.2 mm	0.0079	0.2
#92	0.0079	0.2007
#91	0.0083	0.2108
#90	0.0087	0.221
#89	0.0091	0.2311
#88	0.0095	0.2413
#87	0.01	0.254
#86	0.0105	0.2667
#85	0.011	0.2794
#84	0.0115	0.2921
0.3 mm	0.0118	0.3
#83	0.012	0.3048
#82	0.0125	0.3175
#81	0.013	0.3302
#80	0.0135	0.3429
#79	0.0145	0.368
1/64 in	0.0156	0.3969
0.4 mm	0.0158	0.4
#78	0.016	0.4064
#77	0.018	0.4572
0.5 mm	0.0197	0.5
#76	0.02	0.508
#75	0.021	0.5334
#74	0.0225	0.5715
0.6 mm	0.0236	0.6
#73	0.024	0.6096
#72	0.025	0.635
#71	0.026	0.6604
0.7 mm	0.0276	0.7
#70	0.028	0.7112
#69	0.0292	0.7417
#68	0.031	0.7874
1/32 in	0.0313	0.7938
0.8 mm	0.0315	0.8
#67	0.032	0.8128
#66	0.033	0.8382
#65	0.035	0.889
0.9 mm	0.0354	0.9
#64	0.036	0.9144
#63	0.037	0.9398
#62	0.038	0.9652
#61	0.039	0.9906
1 mm	0.0394	1
#60	0.04	1.016
#59	0.041	1.0414
#58	0.042	1.0668
#57	0.043	1.0922
1.1 mm	0.0433	1.1
#56	0.0465	1.1811
3/64 in	0.0469	1.1906
1.2 mm	0.0472	1.2
1.3 mm	0.0512	1.3
#55	0.052	1.3208
#54	0.055	1.397
1.4 mm	0.0551	1.4
1.5 mm	0.0591	1.5
#53	0.0595	1.5113
1/16 in	0.0625	1.5875
1.6 mm	0.063	1.6
#52	0.0635	1.6129
1.7 mm	0.0669	1.7
#51	0.067	1.7018
#50	0.07	1.778
1.8 mm	0.0709	1.8
#49	0.073	1.8542
1.9 mm	0.0748	1.9
#48	0.076	1.9304
5/64 in	0.0781	1.9844
#47	0.0785	1.9939
2 mm	0.0787	2
#46	0.081	2.0574
#45	0.082	2.0828
2.1 mm	0.0827	2.1
#44	0.086	2.1844
2.2 mm	0.0866	2.2
#43	0.089	2.2606
2.3 mm	0.0906	2.3
#42	0.0935	2.3749
3/32 in	0.0938	2.3813
2.4 mm	0.0945	2.4
#41	0.096	2.4384
#40	0.098	2.4892
2.5 mm	0.0984	2.5
#39	0.0995	2.5273
#38	0.1015	2.5781
2.6 mm	0.1024	2.6
#37	0.104	2.6416
2.7 mm	0.1063	2.7
#36	0.1065	2.7051
7/64 in	0.1094	2.7781
#35	0.11	2.794
2.8 mm	0.1102	2.8
#34	0.111	2.8194
#33	0.113	2.8702
2.9 mm	0.1142	2.9
#32	0.116	2.9464
3 mm	0.1181	3
#31	0.12	3.048
3.1 mm	0.1221	3.1
1/8 in	0.125	3.175
3.2 mm	0.126	3.2
#30	0.1285	3.2639
3.3 mm	0.1299	3.3
3.4 mm	0.1339	3.4
#29	0.136	3.4544
3.5 mm	0.1378	3.5
#28	0.1405	3.5687
9/64 in	0.1406	3.5719
3.6 mm	0.1417	3.6
#27	0.144	3.6576
3.7 mm	0.1457	3.7
#26	0.147	3.7338
#25	0.1495	3.7973
3.8 mm	0.1496	3.8
#24	0.152	3.8608
3.9 mm	0.1535	3.9
#23	0.154	3.9116
5/32 in	0.1563	3.9688
#22	0.157	3.9878
4 mm	0.1575	4
#21	0.159	4.0386
#20	0.161	4.0894
4.1 mm	0.1614	4.1
4.2 mm	0.1654	4.2
#19	0.166	4.2164
4.3 mm	0.1693	4.3
#18	0.1695	4.3053
11/64 in	0.1719	4.3656
#17	0.173	4.3942
4.4 mm	0.1732	4.4
#16	0.177	4.4958
4.5 mm	0.1772	4.5
#15	0.18	4.572
4.6 mm	0.1811	4.6
#14	0.182	4.6228
#13	0.185	4.699
4.7 mm	0.185	4.7
3/16 in	0.1875	4.7625
4.8 mm	0.189	4.8
#12	0.189	4.8006
#11	0.191	4.8514
4.9 mm	0.1929	4.9
#10	0.1935	4.9149
#9	0.196	4.9784
5 mm	0.1969	5
#8	0.199	5.0546
5.1 mm	0.2008	5.1

[rude tim]

Going up .001 is a verry little change. Unless it is a full on race engine that you are looking for the last couple of hp it might be worth it, but on a lake engine it is a waste of time. Also unless you are using a reamer you will not hold tolerance within .001.

[FMP]

Temperature and humidity will change things faster than you can change 0.001 size.