86 SN 2001 - Low idle and eventual stalling
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=48831
Printed Date: November-23-2024 at 11:58am
Topic: 86 SN 2001 - Low idle and eventual stalling
Posted By: gsmith795
Subject: 86 SN 2001 - Low idle and eventual stalling
Date Posted: June-10-2020 at 12:14pm
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Hi All - I did a bunch of searching through existing threads but couldn't quite find one that matched my situation, so apologies if this is a common topic but I'm hoping it's a quick troubleshoot. I spent an afternoon power washing my bilge to get rid of a ton of oil and grease that had accumulated. I tried to avoid engine components but spray may have hit some parts that it shouldn't have. My issue now is that the engine is idling very low, around 200-500 rpm, the tach 'bounces' off a low of 100-200 rpm up to about 500 rpm until it eventually stalls out after 20-30 seconds. What are some of the common issues that would lead to this symptom? I've seen references to the anti-siphon valve, I've also seen people suggest issues with the carb. The engine has been running strong, idling well, and not giving me any issues for years, so it seems like I sprayed something I shouldnt have...  Thanks in advance. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=7756" rel="nofollow - 1986 Ski Nautique 2001 |
Replies:
Posted By: 8122pbrainard
Date Posted: June-10-2020 at 12:21pm
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Tim, Does the engine sound like it's missing on some cylinders? I'd open up as many rubber wiring connectors including plug wires as well as the distributor cap. Let dry, reconnect and see if there's an improvement. ------------- /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: 8122pbrainard
Date Posted: June-10-2020 at 12:25pm
I've found this works great: Dawn dish soap too. Add some water to the bilge, go for a nice long ride so the mix sloshes around and drain. No spraying with the hose. ------------- /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: gsmith795
Date Posted: June-10-2020 at 12:36pm
Doesn't sound like individual cylinders are the issue, sounds more like fuel is insufficient when throttle is in neutral and not supplying the engine properly. When I increase the throttle and raise the RPM's the engine runs smooth and sounds normal. Seems like the engine just isn't getting enough fuel when i'm in neutral. I pulled a couple plugs off the distributor and see no signs of moisture.
Thanks for the tip! I used dish soap as well, but the 'add soap and drive around' approach definitely seems safer than spraying pressurized water into the bilge area.... ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=7756" rel="nofollow - 1986 Ski Nautique 2001 |
8122pbrainard wrote:Posted By: lakedog55
Date Posted: June-15-2020 at 2:47pm
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Turn the idle screw in a little. Works better if you hold throttle open or disconnect at carb. I always forget to put the quick connect back on at carb. ------------- Lakedog55 |
Posted By: 8122pbrainard
Date Posted: June-15-2020 at 3:13pm
Mike, Don't you think Tim should be looking for the problem instead of the "turn the idle screw in" crutch? ------------- /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: gsmith795
Date Posted: June-15-2020 at 3:22pm
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Actually, I have a quick update here. A neighbor who has way more experience than I do stopped by to look at the engine with me and he made a few adjustments: - tightened the four bolts holding each of the two components on the sides of the carb (not sure what those are called) - adjusted the two screws on either side of the carb (again, not sure what these are called) - adjusted the idle screw We were able to get the engine to idle nice and smooth at around 500-600 rpm after these adjustments, and I assumed we had resolved the issue, but when I took the boat out for a quick test ride the engine started to stall out and lose power around 3k rpm's, so it seems we may have fixed one issue and created another.... I'll probably pull my neighbor back over to take another look when I'm back at the lake this weekend. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=7756" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: 8122pbrainard
Date Posted: June-15-2020 at 3:30pm
Did he hook up a vacuum gauge when he made this adjustment? I still think something got wet since didn't the problem start after you washed the bilge? ------------- /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: SNobsessed
Date Posted: June-15-2020 at 7:55pm
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Maybe spark plug wires got wet? ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: gsmith795
Date Posted: June-15-2020 at 8:05pm
pbrainard suggested that as well, I think maybe I need to check more closely. I pulled each plug off the distributor cap and didn't see any signs of moisture so I replaced them, but maybe I need to let them stay off to dry for a bit.
We didn't use a vacuum gauge during the adjustments. Do you know of a writeup on how that would work? I'm guessing my neighbor is probably familiar with that process but just curious if you know of any resources I can look at. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=7756" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: 8122pbrainard
Date Posted: June-15-2020 at 8:49pm
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Tim, https://www.bing.com/videos/search?q=setting+holley+idle+mixture+screws+with+vacuum&docid=607988728288642564&mid=94C8F79C34D4FFD7427094C8F79C34D4FFD74270&view=detail&FORM=VIRE" rel="nofollow - Here's a youtube on setting a Holley idle mix ------------- /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: Crmaverick
Date Posted: June-24-2020 at 1:07pm
| Mine did this and it was from a tiny orifice on the primary metering block that was plugged up. |
Posted By: gsmith795
Date Posted: June-26-2020 at 8:45am
Really helpful, thanks! ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=7756" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: gsmith795
Date Posted: June-26-2020 at 8:56am
After a few adjustments and replacing some old components, it seems we’ve identified and fixed the issue. While we were checking and replacing the points, we found that the distributor cap had a small chip in it at the bottom where it sits on the base, which may have allowed some moisture to get in and caused the bad idle and/or the loss of power happening around 3k rpm. I’ll keep monitoring to ensure things are running smooth, but it seems that ignition and carb are both tuned properly and when all is said and done the boat will have new points, rotor, cap, and fuel filter, and I’ll have a lot of new knowledge  ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=7756" rel="nofollow - 1986 Ski Nautique 2001 |