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dahermit 11-01-2009 14:35:54 205.188.116.20 739323 Report to Moderator	When it is time to change the plugs (8N), is it always necessary to use new plugs? Given that there are no moving parts in a plug, and the center electrode (sometimes wears rounded) can be squared off with a fine file (they used to make them for just that purpose), and re-gapped. I have an air, abrasive spark plug cleaner. It seems that the plugs could be used over and over after reconditioning. What are your experiences? (please no, "...they are cheap enough just to replace...", type of answers.) [Reply]   [No Email]
lha 11-02-2009 03:47:28 24.176.97.9 739428 Report to Moderator	Re: Clean or always new spark plugs? in reply to dahermit, 11-01-2009 14:35:54   Have a set of ch h10s 5yrs,starts&runs great;why change or clean them until they are a problem?---lha   [Reply]   [Send Email]
Dakota Dave 11-01-2009 16:53:54 66.231.110.17 739364 Report to Moderator	Re: Clean or always new spark plugs? in reply to dahermit, 11-01-2009 14:35:54   I clean and reuse them until they become a problem. After a lot of cleanings they will foul faster. Normal practice ror aircraft engines is to pull clean and inspect every 50 to 100 hours. after 500 hours replace them.   [Reply]   [No Email]
Dean 11-01-2009 16:30:46 67.172.13.37 739358 Report to Moderator	Re: Clean or always new spark plugs? in reply to dahermit, 11-01-2009 14:35:54   DH: You can extend the life of plugs used in vintage Ford tractor engines indefinitely by abrasive blasting them when the engine first begins to miss under load. I've been doing this for over 25 years and use plugs until the exterior finish is badly rusted and no longer suits me or I accidently drop one and crack the insulator. Of course you should thoroughly clean the plug with compressed air after blasting. Dean   [Reply]   [No Email]
Paul in MN 11-01-2009 15:43:45 71.210.158.89 739341 Report to Moderator	Re: Clean or always new spark plugs? in reply to dahermit, 11-01-2009 14:35:54   I also have a plug cleaner, and I use it for the engines that carbon up their plugs. It seems that the slightly coarse surface left on the plug electrode allows carbon to build up faster next time. But with low hour usage that may still be a year from now before I have to do it again. Most of our N's do not have enough sparkie voltage to round off the electrode corners, unless it has been used for many years. I don't file them, but do blast them and then blow them out carefully. If it is a customer's tractor, it just gets new plugs...better cold starts and longer life before it needs to be serviced again. Paul in MN   [Reply]   [Send Email]
Bob Harvey 11-01-2009 16:26:11 216.86.96.82 739357 Report to Moderator	Re: Clean or always new spark plugs? in reply to Paul in MN, 11-01-2009 15:43:45   Try using a different abrasive in your plug cleaner, like glass bead or walnut shell. My pal has one and he uses glass bead, not so nasty on the porcelin(sp).   [Reply]   [No Email]
36 coupe 11-01-2009 14:49:29 216.220.251.105 739326 Report to Moderator	Re: Clean or always new spark plugs? in reply to dahermit, 11-01-2009 14:35:54   Abrasive cleaners can leave grit in the plug.plugs have to be washed afterward.Lead deposits fouled plugs.Now that the lead is gone plugs last much longer.   [Reply]   [No Email]
Bruce (VA) 11-01-2009 14:43:53 24.125.26.10 739324 Report to Moderator	Re: Clean or always new spark plugs? in reply to dahermit, 11-01-2009 14:35:54   (please no, "...they are cheap enough just to replace...", type of answers.) Any other answers you don't want to hear?   [Reply]   [Send Email]
dahermit 11-01-2009 15:27:41 205.188.116.20 739335 Report to Moderator	Re: Clean or always new spark plugs? in reply to Bruce (VA), 11-01-2009 14:43:53   No, that is the only one. I am interested in something that I may have overlooked in the logical conclusion that the plug itself if very resilient, not prone to "wearing out", just getting fouled with carbon and needing to be re-gapped. "Just buy new ones", does not impart any meaningful knowledge about why a person should always replace them instead of clean and re-gap. When I was a kid, plugs were always cleaned and reused...why not now? Has conventional wisdom changed?   [Reply]   [No Email]
danh01 11-01-2009 16:55:20 71.28.194.236 739366 Report to Moderator	Re: Clean or always new spark plugs? in reply to dahermit, 11-01-2009 15:27:41   It's your call. If you want to clean and reuse them that's fine. However keep in mind that plugs do wear out over time and not all plugs wear even. Ceramics do lose it's insulative ability. The electrode can only be bent and or filed so many times before it loses it optimum sparking ability. The quality of the materials is sometimes a problem. Remember we live in a disposable society. Alot of things today are used once then thrown away. I normally keep two sets. They only take a few minutes to swap out. And the plugs stay cleaner and last longer and are easier to clean. That way I always have a fresh set to throw in if there's a problem.   [Reply]   [Send Email]
dahermit 11-02-2009 10:33:08 64.12.116.20 739499 Report to Moderator	Re: Clean or always new spark plugs? in reply to danh01, 11-01-2009 16:55:20   "Ceramics do lose it's insulative ability. The electrode can only be bent and or filed so many times before it loses it optimum sparking ability." Other than cracking, how does ceramics lose it's insulating ability? What goes on at the molecular level that would cause that? How does metal loose it's ability to conduct (sparking ability), due to filing or bending? How does the steel change? Can you explain it chemically (molecular changes)?   [Reply]   [No Email]
danh01 11-02-2009 13:01:08 71.28.194.236 739529 Report to Moderator	Re: Clean or always new spark plugs? in reply to dahermit, 11-02-2009 10:33:08   I didn"t mean to ruffle any feathers here. And no I"m not a molecular scientist so no I couldn"t tell you in scientific terms that would satisfy you. But I do have 35 years of experience in tuning up cars trucks and motors of all kinds. Wish I had a nickel for every plug I"ve ever changed. Due to the heat and vibration and stress factors on the plugs the ceramics on a plug over a LONG period of time can become brittle and crack which could cause misfires or worse. Like the other posters said repeated cleaning can cause pitting, corrsion, and loss of material which can cause incorrect firing and loss of power. Depending how you use the tractor it could take years for these things to happen. And depending on how your engine runs it might never happen. Different plugs are made from different materials. Some are better or worse than others. It"s your judgement call what plug to use and whether or not to reuse them when the time comes or replace. Simple as that.   [Reply]   [Send Email]
Getter-Done 11-01-2009 18:10:58 74.240.202.75 739390 Report to Moderator	Re: Clean or always new spark plugs? in reply to danh01, 11-01-2009 16:55:20   Good Comment.   [Reply]   [No Email]
Dave H (MI) 11-01-2009 16:10:27 205.188.116.20 739350 Report to Moderator	Re: Clean or always new spark plugs? in reply to dahermit, 11-01-2009 15:27:41   I heard one guy here repeatedly recommend that you throw out the plugs because you flooded the engine. Seemed like quite a waste to me. I clean em and reuse em.   [Reply]   [No Email]
36 coupe 11-02-2009 14:47:20 216.220.251.66 739540 Report to Moderator	Re: Clean or always new spark plugs? in reply to Dave H (MI), 11-01-2009 16:10:27   I keep 2 plugs in a closed jar of lacquer thinner for my JD H.Change them when they gas foul.   [Reply]   [No Email]