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Post by fred46 on May 26, 2023 10:39:09 GMT -5
Good morning Rick, As we discussed at the spring reunion…I’m a follower of your ‘set timing w/o a timing light’, because it WORKS GREAT! CJ2s have an easy vacuum line, manifold direct to wiper motor, which I just pull and use that port. Looking for clarification to obtain optimum vacuum reading. On my L6–226, that manifold vacuum line goes to the vacuum booster. You mentioned to install a T fitting for the manifold vacuum port. I presume, then one would leave the vacuum line connected to the booster, and during the tuning process, just plug into the extra port at the T. Correct? Or do I disconnect and plug the port to the booster pump? If that’s the case, why install the T?
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Post by Scoutpilot on May 26, 2023 11:33:40 GMT -5
There is no need to disconnect the line to the vacuum pump. That's why the "T" fitting.
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Post by fred46 on May 29, 2023 19:50:41 GMT -5
This engine has a vacuum advance distributor. When timing with a light you disconnect and plug the advance line. What’s the procedure for setting the timing using a vacuum gauge and a vacuum advance distributor?
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Post by Scoutpilot on May 30, 2023 3:57:37 GMT -5
The same. Disconnect and plug the line and the port on the throttle.
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Post by fred46 on Jun 17, 2023 9:16:30 GMT -5
My L6-226 w/ Carter YF 1 barrel and vacuum advance dizzy engine rebuild now has 150 miles. I static timed it at assembly, .20 points, 5* ign. Fired up, runs smooth, no misses at idle or driving. Seems ok. Filled from the beginning with ethanol free ‘pure gas’ as the pump says, its 90 Octane. We know timing needs to be better than 5* at this octane level. Engine runs fine although seems sluggish and first fill up was 9 MPG. So i thought it’s now time for an accurate tuning with some miles on the engine. Following your ‘tuning w/o a timing light’ which I’ve used B4 with outstanding success on my 134’s. Removed vac adv from dizzy and plugged line. Installed T for vac gauge at mani. I achieved 19” of vacuum on a new engine. Probably still seating rings valves. But 19 is acceptable, steady needle. Point dwell at .20 feeler was 25*, so I tweaked and got to the published 39* dwell. It that ok? It just didn’t turn out quite right. I could hear a missing at the tailpipe. During test run it popped/backfired under acceleration. I know all other aspects are good with a new overall rebuild. Dizzy was rebuilt by Advanced Distributors in MN. Recurved for modern fuels. He sent a note suggesting i start at 16*. I’m going to start over with my adjustments. Any thoughts from an expert for tuning a Super Hurricane w/o a timing light? Thank you Rick.
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Post by Scoutpilot on Jun 17, 2023 11:26:09 GMT -5
I see no mention of carb adjustments. Did you adjust the idle stop screw for a higher vacuum reading? Then did you adjust the mixture for the idle rpm? Were the points et at .20" or .020"?
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Post by fred46 on Jun 18, 2023 10:16:51 GMT -5
Yes, Yes, .020 with a feeler then tweaked to 39* with dwell meter. The WO instructions called for idle speed to start at 3 revolutions, that seems very fast for a YF. Idle mixture I started at 1-1/2 turns from bottom.
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Post by brucew on Jun 18, 2023 11:22:06 GMT -5
If you’re only getting 39* of dwell at .020” gap, you may want to check your distributor for wear. BW
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Post by fred46 on Jun 18, 2023 11:39:30 GMT -5
If you’re only getting 39* of dwell at .020” gap, you may want to check your distributor for wear. BW Dizzy was professionally rebuilt/recurved, Not an issue. Started with points set to .020 using feeler gauge. Resulting dwell when running 25*. Tweaked (trial & error) till I hit the published 39*.
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Post by brucew on Jun 18, 2023 13:56:19 GMT -5
25* at .020”? That’s even worse. “Tweaked” to get the “published 39*”? My service manual says 42*. Properly set using an .020” feeler gauge, dwell should be 42*. They should both be right at the same time. BW
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Post by Scoutpilot on Jun 18, 2023 18:31:51 GMT -5
Did you adjust watching the vacuum gauge or the dwell/tach? The vacuum gauge will give better results. And BW is correct, if all you can get is 25º then one or a number of things is out of kilter. Are the points new with the stainless helper spring? If old, did you use a blade feeler or a wire gauge? Were the points set while at a high point on the cam? I know you've been in this hobby a long time and have considerable experience. We're not disrespecting you. We're just asking the pertinent questions.
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Post by fred46 on Jun 26, 2023 17:17:57 GMT -5
Recently drove up hills at 40-45 MPH speed, applying more throttle began to ping, backed off throttle. Still working to dial in running a rebuilt L6-226 w/ Carter YF, rebuilt/recurved dizzy. I’ll proceed as follows… Points are new and have a shiny silver spring, I’ll presume SS. Set point gap to .020 using wire gauge, plugs set to .030 using wire gauge. Warm engine. Disconnect carb to dizzy vacuum advance line and plug. Running at about 600-700 RPM, verify points set using dwell meter to 39* as published on Sun Electric tune up sheet dated 1963 for L6-226 w/ Autolite dizzy. Adjusted advance to achieve highest vacuum. Retard advance to reduce RPM by 100. Lock down dizzy. Adjust idle speed screw to achieve highest vacuum. Adjust mixture screw to achieve idle of 600-700. Or adjust to highest rpm and back off to rich 1/4 turn. Reconnect carb to dizzy vacuum advance line. Any further suggestions or modifications?
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Post by brucew on Jun 26, 2023 18:41:05 GMT -5
My apologies. 39* may be correct for a six, I don’t deal with them. It seems to me that you have the idle mixture screw and the idle speed screw crossed. Adjust the idle speed screw to close as possible to specified idle speed. Adjust idle mixture screw to best vacuum or speed, then IN (lean) until speed reduces by 20 rpm. Then readjust idle speed screw to desired speed. Idle speed and mixture adjustments should be made with the vacuum advance connected. BW
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Post by Scoutpilot on Jun 26, 2023 18:55:49 GMT -5
BW. Sorry buddy that is almost backwards. The steel idle stop screw controls the vacuum. The mixture controls fuel. The trick is to get the proper balance of the two. You are correct in that after adjusting the vacuum with the idle stop screw (I don't know why it is called that) set your mixture for idle rpm then turn it in until the needle on the vacuum gauge begins to bounce, then back out a quarter turn. Work the two screws until all numbers are right.
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Post by fred46 on Jun 26, 2023 21:55:13 GMT -5
Deduced from above comments and mostly extracted from Scoutpilots post “Timing w/o a Timing Light” dated 1/1/15. I’m reading above and getting this…as listed below…any further suggestions or modifications?
Warm engine. Disconnect carb to dizzy vacuum advance line and plug. Run at about 600-700 RPM. Adjust advance to achieve highest vacuum. Retard advance to reduce RPM by 100. Lock down dizzy. Reconnect carb to dizzy vacuum advance line. Adjust idle speed screw to achieve highest vacuum. Adjust mixture screw to achieve smooth idle of 600-700. Or adjust mixture screw to highest rpm then back off to rich 1/4 turn. Road test.
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