carb issue
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=29954
Printed Date: November-24-2024 at 9:16am
Topic: carb issue
Posted By: 176fan
Subject: carb issue
Date Posted: May-22-2013 at 6:14pm
| I just bought a 1997 Ski Nautique 176 with a carbed PCM 351 in it. I had been looking for one for a while and finally found one in good condition with low hours, but it seems to be having a problem with the carb. It runs great at idle and plane speeds (above 2500 rpm), but it dies out anywhere between those. Any suggestions on what might be going on and how to possibly fix it? Thanks! |
Replies:
Posted By: Bri892001
Date Posted: May-22-2013 at 6:22pm
| Does it die out when accelarating? Or just trying to cruise at those speeds? |
Posted By: 176fan
Date Posted: May-22-2013 at 6:33pm
| I won't actually run long enough to tell the difference really. Even if it just rev it in neutral within that rpm range, it will rev then sputter and die within a few seconds. |
Posted By: storm34
Date Posted: May-22-2013 at 6:46pm
|
Carb novice but accelerator pump?? Signing up to see what you discover. ------------- |
Posted By: 176fan
Date Posted: May-23-2013 at 11:47am
| The accelerator pump seems to be working. When I open the throttle, I can see it injecting fuel into the carb, but after that initial injection, it stops, which is what it is supposed to do as I understand it (but I'm not expert). |
Posted By: backfoot100
Date Posted: May-23-2013 at 12:20pm
|
A little more specific detail on the issue. You say at idle and above 2500 but dies out anywhere in between. How does it start? How does it accelerate? Does it die on acceleration or deceleration? Has anything been done to the carb like a rebuild that you know of? If it sputters and dies out at any RPM range what are you doing to get it to planing speeds? ------------- When people run down to the lake to see what's making that noise, you've succeeded. Eddie |
Posted By: 176fan
Date Posted: May-23-2013 at 7:31pm
|
Ok, here is a better description, maybe. Once warmed up, it starts fine just at idle. To cold start it, I give it about half throttle, and once it fires, I immediately bring it back to idle. To get to planning speeds, I have to give it about 3/4 of full throttle to get it going without dying and then can back it off as long as I stay about about 2500 rpm. Basically, I can't slowly increase the throttle from idle because it will initially start to accelerate for a couple seconds then sputter and die. |
Posted By: halfnelly
Date Posted: May-23-2013 at 7:45pm
| If you're getting a bad miss in a specific RPM range, I would think the culprit is probably more ignition related than fuel. If it was excessively lean or rich it would probably be affecting a wider RPM range than just around 2500 RPM. Is the carbed 351 you have a Pro Boss with the magnetic pickup distributor and the module/coil packs on the back of the engine? Could be the module is going bad. |
Posted By: backfoot100
Date Posted: May-23-2013 at 10:10pm
|
Adam, If you just picked up the boat, I would go through it completely. Change fluids and do a complete tune up. You haven't said what ignition you have. I assume it's electronic so plugs, cap, rotor and set the timing. Then run it and see what we have for a baseline. A tune up can do wonders. ------------- When people run down to the lake to see what's making that noise, you've succeeded. Eddie |
Posted By: Bri892001
Date Posted: May-23-2013 at 11:16pm
|
Agree with both posts above. Would the springs being totally gone from the distributor advance weights cause something like this? Like, if it was able to advance all at once with little/no resistance? |
Posted By: 176fan
Date Posted: May-24-2013 at 9:41am
| The engine is not a Pro Boss. The distributor sits on the top of the engine toward the front. I did just get the boat, and I am in the process of going through and doing maintenance and finding issues. I am a complete novice in DIY engine work, so it's a working progress. Thanks to everyone who is providing input, I appreciate the help. |
Posted By: backfoot100
Date Posted: May-24-2013 at 10:11am
I wouldn't rule out ignition or something in the carb right now. A good tune up may just fix it or at the very least rule out the ignition. ------------- When people run down to the lake to see what's making that noise, you've succeeded. Eddie |
Bri892001 wrote:Posted By: SNobsessed
Date Posted: May-24-2013 at 10:14am
|
If the advance springs were broken, the weights would go to full advance & stay there. I think it would not idle nor restart well after that. You also would be getting some backfiring. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: 176fan
Date Posted: July-02-2013 at 4:33pm
|
I just wanted to update everyone who was providing feedback on my problem. Thank you for all of your suggestions. I've finally had the time to rebuild the carb, and that fixed all of the issues. Thanks again for all of your feedback. I'm ready to go enjoy my new toy now. Adam |