Igor_U Posted December 2, 2019 Report Share Posted December 2, 2019 (edited) My IA installed a new mechanical fuel pump and had to remove Left Mag (Slick 4347). After all was installed back, engine wouldn’t start. Electric fuel pump would pressurize but no start and at the end we had some backfire (pooping). Battery and starter (Skytec) run good. It seems everything is connected right now. Originally Retard and P-Lead on LH mag were reversed. Before this I never had had an issue with mags and ignition. Shower of spark is making noise but we didn’t test (yet) per Don Maxwell’s article. What is the chance of SOS being defective if making noise? Seems left mag could be the issue if SOS is good (we’ll test it)? Mags are at 500h so now I’m at the crossroads, what to do. New Slick? Sending for OH or Surefly ignition? My current IA is not equipped to work on mags and would like to send out or replace. How hard is to diagnose faulty cap or retarding points? My thinking is replace left mag now if I have to (Slick or maybe Surefly) and next annual do the Right mag. Am I missing something? It could be just coincidence but I find hard to believe that just a removal of the mags would cause the issue… Thanks. Edited December 2, 2019 by Igor_U Quote Link to comment Share on other sites More sharing options...
MB65E Posted December 2, 2019 Report Share Posted December 2, 2019 Send both mags for a 500hr inspection. Use the search for accessory shops in your area. I prefer RLB accessory in the Chicago suburbs. -Matt Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted December 2, 2019 Report Share Posted December 2, 2019 Mag is probably 180 degrees off. It will look like it is timed right, but it is firing on the exhaust stroke. The red tooth is your friend. 4 Quote Link to comment Share on other sites More sharing options...
chriscalandro Posted December 2, 2019 Report Share Posted December 2, 2019 Just now, N201MKTurbo said: Mag is probably 180 degrees off. It will look like it is timed right, but it is firing on the exhaust stroke. The red tooth is your friend. This! Quote Link to comment Share on other sites More sharing options...
Guest Posted December 2, 2019 Report Share Posted December 2, 2019 If it worked before it was removed, it may simply be installed and timed wrong. No red tooth on a Slick magneto, it uses a timing pin inserted through the distributor block once the wire set is removed. Clarence Quote Link to comment Share on other sites More sharing options...
Prior owner Posted December 2, 2019 Report Share Posted December 2, 2019 Does the Slick mag have an index feature on the cap? (I don’t remember) I have seen Bendix mags re-installed and timed correctly, but the wire cap installed / indexed incorrectly. Discovered while Sparking out the leads after much “pooping” On start. Quote Link to comment Share on other sites More sharing options...
Igor_U Posted December 2, 2019 Author Report Share Posted December 2, 2019 Interesting on reversing the mag 180 deg. I was there when it was timed at 25 deg: CYL 1 at TDC using the box and it was on the 25 deg mark on the flywheel. Mag was on it already. How would I know it's upside down? What I've noticed is LHS has label with p/n on top (and the P-lead attachment stud) while RH mag has label with P/N on the bottom, as well as P-lead stud. Is that how they come? I didn't have any pictures of Left mag before. So, if no red tooth, is it still possible to install it wrong? IA mentioned he marked the the wire set orientation before removal. 2 hours ago, M20Doc said: If it worked before it was removed, it may simply be installed and timed wrong. No red tooth on a Slick magneto, it uses a timing pin inserted through the distributor block once the wire set is removed. Clarence Thank you all. Quote Link to comment Share on other sites More sharing options...
EricJ Posted December 2, 2019 Report Share Posted December 2, 2019 (edited) As mentioned, the slicks don't have the red tooth like the Bendii do. When the mag is off the airplane is can be positioned to #1 and pinned, and then the engine set to the compression stroke on #1, then the pin removed after installation. If he marked the cap that should go back on correctly without an issue. Slick mags are pretty simple and easy to work on, but have some significant differences to the Bendix equivalents. Having the timing mark in the right place is still ambiguous to whether the engine is on the compression or exhaust stroke. Need to do the thumb-on-the-plug-hole trick or something similar to distinguish which it is. If it is the wrong stroke it won't do anything, consistent with what was described. Edited December 2, 2019 by EricJ 1 Quote Link to comment Share on other sites More sharing options...
Guest Posted December 2, 2019 Report Share Posted December 2, 2019 When the timing pin is installed in the magneto, there are 2 holes 1 for right rotation, 1 for left rotation. The magneto data plate states the rotation of the magneto, the pin is installed in the corresponding hole. The wrong hole will mess up the timing. Clarence Quote Link to comment Share on other sites More sharing options...
carusoam Posted December 3, 2019 Report Share Posted December 3, 2019 Inviting @DXB to gain some additional Mag knowledge... Best regards, -a- 1 Quote Link to comment Share on other sites More sharing options...
DXB Posted December 3, 2019 Report Share Posted December 3, 2019 3 minutes ago, carusoam said: Inviting @DXB to gain some additional Mag knowledge... Best regards, -a- Kinda hoping my recent in flight practical course on magneto problems has concluded at this point . 1 Quote Link to comment Share on other sites More sharing options...
Shiny moose Posted December 3, 2019 Report Share Posted December 3, 2019 Just remove it and as Clarence stated, check for the correct pin locating hole , pin it and reinstall. Sometimes you just gotta start over 1 Quote Link to comment Share on other sites More sharing options...
chriscalandro Posted December 4, 2019 Report Share Posted December 4, 2019 The cap can only go on one way. Quote Link to comment Share on other sites More sharing options...
Browncbr1 Posted December 4, 2019 Report Share Posted December 4, 2019 My IA says it is possible to reinstall the mechanical fuel pump without getting the plunger in the right spot so that it won’t pump. I remember all of us crossing fingers when we fired mine up the first time after r&r. Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted December 4, 2019 Report Share Posted December 4, 2019 25 minutes ago, Browncbr1 said: My IA says it is possible to reinstall the mechanical fuel pump without getting the plunger in the right spot so that it won’t pump. I remember all of us crossing fingers when we fired mine up the first time after r&r. That’s true, but it will start with the electric pump on. 2 Quote Link to comment Share on other sites More sharing options...
David Lloyd Posted December 4, 2019 Report Share Posted December 4, 2019 Are you certain fuel is being pumped to the servo? Problem is either dinosaurs or sparks. Quote Link to comment Share on other sites More sharing options...
Igor_U Posted December 4, 2019 Author Report Share Posted December 4, 2019 Well, electric pump is working and engine monitor (EI CGR30P - taking reading after servo) is in the green as it should. We'll have a look further this weekend. 12 hours ago, David Lloyd said: Are you certain fuel is being pumped to the servo? Problem is either dinosaurs or sparks. Quote Link to comment Share on other sites More sharing options...
amillet Posted December 4, 2019 Report Share Posted December 4, 2019 Mags are at 500h so now I’m at the crossroads, what to do. New Slick? Sending for OH or Surefly ignition? Our factory reman now has 428 hours with annual due in April. I’m leaning towards putting a Surefly on rather than overhaul that one Quote Link to comment Share on other sites More sharing options...
Igor_U Posted December 22, 2019 Author Report Share Posted December 22, 2019 We finally managed to get together yesterday, removed and installed magneto, timed it and engine still would not start. SOS is seems working... buzzing sound and all. With Mag approaching 500h I lean towards replacing LH mag with Surefly. I would really like to do this at annual but I didn't think we can have this mag going without sending it out for OH (or IRAN) as my current IA is not equipped to test and repair mags. Not sure what's the best to do as I'd like to investigate Surefly more but seems few installs on MS went well and owners like them. The rub is how can I be sure it's a mag? it was removed and installed with not internals disturbed. El fuel pump works and it showed pressure on Engine monitor when on so engine should start if there's spark, right? Nothing to do with mechanical pump as that one comes online only after the start... Quote Link to comment Share on other sites More sharing options...
carusoam Posted December 22, 2019 Report Share Posted December 22, 2019 Fuel pressure... check... Air unobstructed... check... Shower of sparks buzzing... check... (does buzzing always means working properly?) there is room for error here...(?) Mag timing retard circuit... this is the part of the mag that allows for engine start... it fires off at TDC instead of BTDC.... Often when the ignition switch is held on... and nothing starts... release of the ignition switch allows for the engine to fire... This is an indication of the one mag not working properly, and the other making up for it when it is brought on line with the ignition switch in the both position... Sorry for being vague and probably repetitive.... PP trying to add thoughts in a technical area... not a mechanic.. Best regards, -a- Quote Link to comment Share on other sites More sharing options...
jamesm Posted December 22, 2019 Report Share Posted December 22, 2019 I am not too sure how well this work since you said you had slick magnetos., I am not sure if you can mix and match bendix and slick, since I have never heard of any one doing this. but I just pulled my left Bendix S200 that has about 320 hrs on the Mag off 0360A1D from a'67C and pulled the SOS box. I installed the Surefly on the left side. I can NOT yellow tag it but if you want try it for ground run only .... I am about 25 nm south of you \@ KRNT. James Quote Link to comment Share on other sites More sharing options...
Prior owner Posted December 22, 2019 Report Share Posted December 22, 2019 Have you verified that you are getting fuel at the injectors? Quote Link to comment Share on other sites More sharing options...
skykrawler Posted December 22, 2019 Report Share Posted December 22, 2019 If the p-leads for the magnetos are backwards the ignition switch which normally drops out advanced magneto is instead grounding the other then it would be hard to start and might kick back or backfire. Quote Link to comment Share on other sites More sharing options...
Shadrach Posted December 22, 2019 Report Share Posted December 22, 2019 1 hour ago, Igor_U said: We finally managed to get together yesterday, removed and installed magneto, timed it and engine still would not start. SOS is seems working... buzzing sound and all. With Mag approaching 500h I lean towards replacing LH mag with Surefly. I would really like to do this at annual but I didn't think we can have this mag going without sending it out for OH (or IRAN) as my current IA is not equipped to test and repair mags. Not sure what's the best to do as I'd like to investigate Surefly more but seems few installs on MS went well and owners like them. The rub is how can I be sure it's a mag? it was removed and installed with not internals disturbed. El fuel pump works and it showed pressure on Engine monitor when on so engine should start if there's spark, right? Nothing to do with mechanical pump as that one comes online only after the start... You can’t be sure. You had a running engine before the fuel pump replacement, correct? If so, you had a working ignition system before a human hands got involved and “fixed it”... The solution is not to throw parts at it. Given your willingness to replace a mag that was working just a few seconds ago, I’m curious about why the mechanical fuel pump was replaced. 1 Quote Link to comment Share on other sites More sharing options...
N201MKTurbo Posted December 22, 2019 Report Share Posted December 22, 2019 You don't need fancy equipment to test the mags. Take out at least all the top plugs so the engine will spin freely. Attach the leads to the plugs and lay the plugs on top of the cylinders. Have someone hit the starter and look at the plugs to see if they are sparking. With the shower of sparks, you can move the prop till the points open and you should see continuous sparks. If you leave the bottom plugs in, blow out the cylinders with compressed air before doing this. If there are fuel vapors in the cylinder, it may light off and make a bang like a shotgun going off. Ask me how I know? 4 Quote Link to comment Share on other sites More sharing options...
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