Drop in pressure slight vibration
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=49009
Printed Date: October-05-2024 at 10:28pm
Topic: Drop in pressure slight vibration
Posted By: Atomic Dam
Subject: Drop in pressure slight vibration
Date Posted: July-06-2020 at 12:30pm
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Once again in need of all of your wisdom. 1975 Southwind 20, escort 351. I was out this weekend, engine was running strong without issue. Saturday, I noticed that the oil pressure seemed a little low. By little, I mean just below the 40 mark at speed, but it usually is sitting right on the mark. I checked the oil, she was full, and since it was a slight decrease, I decided to just monitor. Sunday, when I went to pull her out of the water I was running about 2200rpm just in plane for about 20 min, when it felt like someone bumped the throttle down and started a noticable a vibration. we dropped out of plane without any change in throttle and the oil pressure dipped even lower. I dropped her to an idle, and she idled fine, but when getting back up to speed the vibration was still present and it was noticeably running with with less power. I immediately put her on the trailer so I could investigate further. Can someone offer me a place to start or even better, a list of of things to inspect that would cause something like this? Currently around 600 hours. ------------- Please support The Cystic Fibrosis Foundation OEF/OIF US Army Combat Veteran '75 Southwind 20 Escort 351W |
Replies:
Posted By: 8122pbrainard
Date Posted: July-06-2020 at 12:47pm
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John, Sounds like the RPM drop was from 1 or more cylinders not firing but could also be a fuel issue. When was the last ignition tune up done? Has the carb ever been touched/ As far as the oil pressure goes, here's the: " rule of thumb for acceptable oil pressure is pretty close to 10 psi per thousand rpms." ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: GottaSki
Date Posted: July-06-2020 at 1:14pm
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Like Pete sez. next steps inspect plugs for any irregular, and do a compression survey ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: Atomic Dam
Date Posted: July-06-2020 at 1:44pm
The carb was replaced at some point, but when I could not say. It has a Holly 4bbl on it now. It also had an electronic ignition installed. Both the ignition and the carb were professional installs. Outside of that there are no engine modifications. I don't knwo when the last tune up was done. If I remember correctly, the P.O. said either last season, or the previous. ------------- Please support The Cystic Fibrosis Foundation OEF/OIF US Army Combat Veteran '75 Southwind 20 Escort 351W |
8122pbrainard wrote: