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WOT only 3400RPM???

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=14588
Printed Date: November-21-2024 at 9:10pm


Topic: WOT only 3400RPM???
Posted By: rmm025
Subject: WOT only 3400RPM???
Date Posted: July-22-2009 at 11:46pm
I have an 86 2001 and I am having WOT issues. I can only get 3400rpm and 35mph out of it. 351W, velvet drive 1:1 tranny, seems to be original 3 blade prop. There also seems to be a slight miss in the engine, but I can't pinpoint it. Any suggestions???



Replies:
Posted By: SNobsessed
Date Posted: July-23-2009 at 12:00am
Look to see if the secondaries are working. Leave the motor box at home; watch the secondaries throttle shaft to see if it opens up after 3000 RPM. There is a vacuum diaphram that could have a rupture. You can't do this in the driveway, it has to be under power.

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“Beer is proof that God loves us and wants us to be happy.”

Ben Franklin


Posted By: rmm025
Date Posted: July-23-2009 at 10:42am
I will go check it out today, BTW I have a freshly rebuilt carb, so I would hope I don't have a rupture. But I have had a fuel problem, filter almost completely filled with water and crud, changed it and fuel just in case, checked all fuel lines and anti-siphon valve. Engine was stalling now it hangs at 3400. Could water in the carb cause the secondaries not to open? I didn't take the carb back apart after I found my water, I drainded the fuel inlet, and filled the filter half way up with seafoam and added the rest to my tank to try and get rid of any residual water in the carb.


Posted By: SNobsessed
Date Posted: July-23-2009 at 10:48am
You should take the secondary bowl off & put in a new seat & needle, check the float level setting. I am not sure, but the secondary diaphram might not come with the kit, so that still may be a possibility - check your kit instructions. You could go so far as to look down the carb throat while at WOT to see if gas is going down the seconadries.   This is a bit risky so be careful!

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“Beer is proof that God loves us and wants us to be happy.”

Ben Franklin


Posted By: BuffaloBFN
Date Posted: July-23-2009 at 11:15am
Backfoot mentioned a neat trick if you're trying to check the secondaries by yourself. The trick is to put a paperclip on the secondary actuator rod. If they open the clip will move.

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http://correctcraftfan.com/diaries/details.asp?ID=2331&sort=&pagenum=12&yrstart=1986&yrend=1990" rel="nofollow - 1988 BFN-sold



"It's a Livin' Thing...What a Terrible Thing to Lose" ELO


Posted By: rmm025
Date Posted: July-23-2009 at 11:57pm
Ok, I wasn't able to take the boat out today, but I did some at home diagnostics instead. I checked the secondary diaphram and fuel bowl area, everything looked good. The secondary diaphram wasn't included in the rebuild kit but looked fine. The most important thing I found was that the firing order was off. Cylinders 7 & 8 were fliped. Got them correct and the engine ran better of course. I will take it out tomorrow and check to see if the secondaries are opening. Would the firing order problem also cause the hesitation at 3400rpm? I am quite sure it was causing my miss. I also am planning on checking compression tomorrow.


Posted By: TRBenj
Date Posted: July-24-2009 at 5:02pm
Originally posted by rmm025 rmm025 wrote:

Would the firing order problem also cause the hesitation at 3400rpm? I am quite sure it was causing my miss.

Since you were only running on 6 of the 8 cylinders, Id say you have found your culprit!

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Posted By: rmm025
Date Posted: July-25-2009 at 12:06am
Culprit definately found, she ran great today.



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