Stiff trottle
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=2226
Printed Date: November-23-2024 at 3:39am
Topic: Stiff trottle
Posted By: stang72
Subject: Stiff trottle
Date Posted: August-10-2005 at 12:30am
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My thottle is a bit stiff when engaging...if I remove the return spring from the carb linkage to the block , it is smooth and moves with ease.
Any reason to keep a spring on? Are there ajustments on the holley carb that increase or decrease tention? It does not appear that the cable is binding and the morse control seems fine . I never had a problem before switching carbs??? Thanks GH ------------- stang Face plants are not that funny when it's you face! http://www.correctcraftfan.com/diaries/images/3720/photo1.jpg" rel="nofollow - The Super Air |
Replies:
Posted By: nates78ski
Date Posted: August-10-2005 at 8:54am
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Remove the return spring. Marine engines do not use return springs because the rely on a positve push/pull cable for operation. The carb you put on may have worn throttle shaft bushings & the add pull from the spring is causing the stiffness & making the problem worse. ------------- Nathan http://correctcraftfan.com/diaries/details.asp?ID=1463&sort=&pagenum=3&yrstart=1978&yrend=1978" rel="nofollow - My '78 Ski Nautique <a href="http://photobucket.com/Nates78ski" rel="nofoll |
Posted By: GottaSki
Date Posted: August-10-2005 at 11:38am
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Nothing personal Nate but thats some of the worse advise I've seen on the net.
If, no when the cable breaks or the brass cable ends are sawed through by the morse control (yes, I have seen this occur three times for each) the kids you hit would say leave the return spring on, and btw replace the cables with fresh morse red-jackets, when given the chance. If the cables are over 15 years old they can go at anytime; you could get another 5 years out of them or another week. Personally I'm not that lucky. You can count on these things failing at the worse possible time. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: stang72
Date Posted: August-10-2005 at 12:14pm
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Well...as I scratch my head??? good point about the cable breaking ...but I could turn the ignition off and kill the engine just about a fast!
The carb is new...bushings should be fine.Cable could be suspect. Replacing cables ...might be time for that. Stang72 ------------- stang Face plants are not that funny when it's you face! http://www.correctcraftfan.com/diaries/images/3720/photo1.jpg" rel="nofollow - The Super Air |
Posted By: GottaSki
Date Posted: August-10-2005 at 12:53pm
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Well, you could turn the engine off and then be somewhat out of control, because these boats can turn and stop very poorly without power.
Plus, i suspect you may ski as well as drive, would you trust your driver to have the same top-gun reactions you have? Do you ever let others take the boat out, just things to send the point home.. Thanks for considering, and regret being so mater-of-fact, just seen so many close calls and accidents over the years, hate to see somebody build one into their boat. Fresh cables and ends are cheap peace-of-mind considering the proximity we navigate these boats to people in the water. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: stang72
Date Posted: August-10-2005 at 1:27pm
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I did think of that aspect shortly after my last post..."others driving" and while I would react fast , others may not have a clue...very good point!
New cable and the spring stays! Thanks for the perspective! Stang72 ------------- stang Face plants are not that funny when it's you face! http://www.correctcraftfan.com/diaries/images/3720/photo1.jpg" rel="nofollow - The Super Air |
Posted By: David F
Date Posted: August-10-2005 at 3:52pm
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Maybe you just need a lighter spring. Might try disconnecting the throttle cable and then find the lightest spring that would fully return the throttle to idle. Then, go at least one heavier so ensure that the spring can overcome the internal friction of the broken cable. Or better yet, disconnect the throttle cable at the control and find the lightest spring that will return the throttle to idle.
Can you attach the cable to a spot on the throttle arm that imparts more leverage and hence will reduce effort, but increase throw. |
Posted By: Jim_In_Houston
Date Posted: August-10-2005 at 4:01pm
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My Holly has a small circular "wind-up" spring that the carb throttle plate shaft passes through. When I disconnect the throttle cable this spring keeps the throttle plates closed. I thought all of the Holly's had this spring. Appearantly I thought wrong. ------------- Happy owner of a '66 and a '68 Mustang |
Posted By: JEFF KOSTIS
Date Posted: August-11-2005 at 1:08am
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Jim In Houston, I thought the same. I have not seen a carb where when sitting the throttle plates are wide open. Maybe his spring is broken, and the add on return spring is used to make up for a defective or misadjusted cable or control. ------------- MUSTANG COUNTRY http://www.correctcraftfan.com/diaries/details.asp?ID=1074 - 1974 Mustang 17 http://www.correctcraftfan.com/diaries/details.asp?ID=1093 - 1976 Mustang 17 |
Posted By: stang72
Date Posted: August-11-2005 at 3:12am
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Jim and Jeff...you are both right! Without the return spring, it still closes the plates...so why do I need a return spring if the "wind-up" spring closes the plates...back to top of the post ... "Is there any reason to keep a spring on"? I guess not... as long as it will snap shut if the cable breaks...and only adds extra tention.
I have the same carb on an 83 MC prostar...it also has a return spring( all the ones I have seen do)...and the plates will close without it ...however that thottle control works fine. So...Sense the plates will shut ,it makes me wonder why the return springs are there. Thanks all for the input Stang72 72 mustang 62 classic and er um a... 83 MC stars and stripes ------------- stang Face plants are not that funny when it's you face! http://www.correctcraftfan.com/diaries/images/3720/photo1.jpg" rel="nofollow - The Super Air |
Posted By: Jim_In_Houston
Date Posted: August-11-2005 at 3:52am
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Hey! We had an MC in 1983. He kept playing Billie Jean over and over - it still made for a nice disco party though. That is what you mean by "83 MC". Right? Wait. He was a DJ not an MC. What is an MC? ------------- Happy owner of a '66 and a '68 Mustang |
Posted By: stang72
Date Posted: August-11-2005 at 5:15am
Ok...I set myself up for a little slapping arround and I new it would be comming!
MC...is'nt that the guy who conducts or hosts the Miss America pagent? Stang72 72 mustang 62 classic other? ------------- stang Face plants are not that funny when it's you face! http://www.correctcraftfan.com/diaries/images/3720/photo1.jpg" rel="nofollow - The Super Air |
Posted By: David F
Date Posted: August-11-2005 at 5:07pm
| I believe the return spring is designed to overcome the friction within the throttle cable if the break should happen to occur at the control. I doubt the spring at the throttle shaft would be sufficient. |
Posted By: Bob's2001
Date Posted: August-11-2005 at 10:27pm
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Keep the spring and change the cable and the little brass thingamabob on the control end. I had both of those break in space of a month. ------------- Bob Ed 83 2001 |
Posted By: GottaSki
Date Posted: August-11-2005 at 11:36pm
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I concur with David. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: JEFF KOSTIS
Date Posted: August-12-2005 at 12:45am
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What David F says makes perfect sense, why do some have them and some not?? Plus, that would have to be a heavy return spring to overcome the resistance of a old, stiff cable.Whats even more fun is I had the throttle handle break off while going WOT from 25 mph. When I went pull back, it fell in my hand as we hit a 4 foot wave and the nose dug in, the rear went straight in the air, and the poor old OMC 225 screamed as the prop was in the air. I Shut off the key, she dieseled for a while since after I killed it. When she slammed back down, it destroyed the prop (beyond rebuild). It all happened so fast!!! Further inpection revealed a cast defect in the aluminum. ------------- MUSTANG COUNTRY http://www.correctcraftfan.com/diaries/details.asp?ID=1074 - 1974 Mustang 17 http://www.correctcraftfan.com/diaries/details.asp?ID=1093 - 1976 Mustang 17 |
Posted By: Guests
Date Posted: August-14-2005 at 2:07am
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After giving it a test...disconnecting the cable @ the control box...it is iffy!!! iffy is getting near murphy's law...and not OK! Also...I noticed , that setting a good idle Rpm was difficult...the return spring when on helps when setting the idle down...there is not enough tention to get lower idle settings without it!When using a stiffer spring , I could turn the idle lower...without a spring , it would stop at a certain point where I thought there was no more adjustment....with the spring on I could turn it down quite a bit more. That would indicate to me that the cable is too stiff due to old age.
Spring stays and the cable is to be replaced!!! 
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Posted By: David F
Date Posted: August-14-2005 at 12:39pm
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When you replace the cable, there is one important thing to remember. You must have the throttle in the forward idle position (i.e. in gear, no throttle) WHILE you adjust and connect the cable at the carburetor throttle arm. This method properly preloads the spring at the controller.
Also, if the return spring is too strong, the throttle will tend to creep back while underway and it is more diffilcult to hold speed. |
Posted By: nates78ski
Date Posted: August-14-2005 at 1:26pm
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The point I was try to make was to remove any
springs added to the carb or who knows elsewhere trying to solve some other problem. The problem lies in one of three areas, cable, control, or carb. People add springs to return the throttle because of cable drag or control problems. If you add a non factory spring to the carb you a most likely binding the throttle shaft. The throttle shaft has a shaft spring on it to close the throttle in the event the cable or control fails(that is the only reason that spring are there). Any added springs will increase stiffness & will result in increasing wear of the throttle shaft. Replace the cable, check the results, if problem persists remove the control any service or replace it. Also check cable routing for wide sweeping radius & smooth operation. ------------- Nathan http://correctcraftfan.com/diaries/details.asp?ID=1463&sort=&pagenum=3&yrstart=1978&yrend=1978" rel="nofollow - My '78 Ski Nautique <a href="http://photobucket.com/Nates78ski" rel="nofoll |
Posted By: stang72
Date Posted: August-14-2005 at 4:34pm
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David F...Thanks for that info! I have set my throttle connection to the arm in the neutral position...I would think that would have an effect on how the idle adustment works( I have to turn the screw back as far as it will go to get it to idle near where I want it to be)...I noticed it will go back more with more tention.. maybe that is part of the problem.
Still...I will swap cable just to make sure the cable is not the problem! ------------- stang Face plants are not that funny when it's you face! http://www.correctcraftfan.com/diaries/images/3720/photo1.jpg" rel="nofollow - The Super Air |
Posted By: stang72
Date Posted: August-18-2005 at 2:16am
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After readjusting the cable at the throttle arm (Moving it to forward idle)all is much better...pre loading the spring has made a difference in the stiffness!!! I changed to a lighter spring as well.
Also ...I am able to set the idle speed back quite a bit more. My timing needed to be advanced a bit to get more power...when doing so , I was unable to set the idle low enough...it would not adjust any further. Now my timing and idle are where they should be  Boat ran great today...almost hit 50 mph!!! and idle is @ 600 rpms.
Thanks David F for the tip...solved more than one problem!!! ------------- stang Face plants are not that funny when it's you face! http://www.correctcraftfan.com/diaries/images/3720/photo1.jpg" rel="nofollow - The Super Air |