engine bogging down no power
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=19066
Printed Date: June-26-2024 at 1:50pm
Topic: engine bogging down no power
Posted By: bmiller
Subject: engine bogging down no power
Date Posted: August-16-2010 at 12:37pm
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Ok guys its been a long time since I've been on the site but I'm having some issue's with my 1978 mustang.Some feed back would be nice if you don't mind.First some info you guys need to know about the boat.The engine is a stock 302cid.Theres only 338 hours on the engine.I have the Prestolite breakerless ingnition kit installed in the distributor to replace the points and condenser.I also have the electronic coil installed for this breakerless kit.The 4160 Holley carb that I have installed on the boat is only 4 years old.This boat has run flawlessly within this time period that I'm talking about.A week and a half ago on the last day of vacation the boat started to act funny out of the blue.I was riding down the lake doing about 20 to 25mph and all of a sudden without touching the throttle the boat started to to die and loose power and then all of a sudden it would it would lundge and regain power.At times for the rest of the day the boat would run fine.It kind of acted like I got a bad tank of gas or I thought I might have a ignition coil starting to go bad on the boat,so I went on ahead and got a replacement coil from SKIDIM.Thinking that I may have solved the problem I took it for a test this past Friday and the boat ran great for about 30 minutes.All of a sudden without touching the throttle it would die and loose power and regain it again.At this point I'm now working the throttle back and forth and not getting any response from the engine.So I would back it back down into idol postion and give it gas.Sometimes it would respond to the throttle and somtimes it wouldn't.There are times where I could give it full throttle and the boat would just bog down and I would only be showing 1800 rpm on the tach,then it would catch and bog right back back down and sounded like it was missing very badly.So my thinking is either the breakerless kit starting to go bad or my carb is not functioning like it should.
So this is what I've done.Once I get the boat on the trailer,I did the normal checking of the plugs,wires,inline fuel filter,the little screen filter in inlet of the carb to make sure nothing was loose or clogged.Nothing was found out of the ordinary.I even cleaned the vacuum screen on the carb.Once that was all done I started the boat back up on the trailer and it idols great.I even put a vacuum gauge on the engine to check the timing and I'm getting 18 to 20 inches of vacuum when the engine is up to temp and idoling. Yesteraday I put the boat back in the water with tools in hand.Start the boat up,it idols great at the dock.I start to leave the dock and give it gas and its just a dog.It just can't get out of water.Its missing and then the engine will just shut off.You can put it right back into neutral start it right up again,it idols fine,give it gas and it will either die right then and there or it will run for a little bit,sound like hell and die again. So my thought now is that it can't be the Prestolite breakerless kit going bad because the engines idols fine.My thinking is that its a carb issue now.I can pull the throttle button out and give the engine gas just sitting there and it will respond every time and rev normally.Put it into gear and it sputters,chokes and dies on me every time.The area where I live at they gas stations have ethanol in the gas and I'm thinking that could be my problem.I just would like to diagnose the problem properly instead of throwing and ton of money that doen't need to be spent.Any feedback would be great guys if you can help me. |
Replies:
Posted By: 8122pbrainard
Date Posted: August-16-2010 at 12:50pm
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Brian,
This does sound more fuel related than ignition. The ethanol is fine for the engine however it does loosen up years of crud in the bottom of the tank. This can plug up the anti siphon valve. It's the fitting on top of the tank next to the 90. check it out. Next, I'd get a pressure gauge "T'd" into the fuel line to the carb. Your fuel pump may be acting up. The gauge will tell you. ------------- /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: 79nautique
Date Posted: August-16-2010 at 12:55pm
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Check the fuel pressure. Is there fuel in the clear line going to the carb? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: bmiller
Date Posted: August-16-2010 at 1:17pm
| 79 to answer your question,yes the inlne fuel filter is clear and you can see the fuel going through as the engine is running.My question is if the engine responds with me giving it gas in neutral postion how can the fuel pump be the issue when I put it in gear and it dies?Can you give me a psi that I should be looking for when I tee into the line.Peter,I have not checked the anti siphon yet because I figured if I'm getting fuel that its working properly. |
Posted By: 79nautique
Date Posted: August-16-2010 at 1:55pm
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you don't have to T in to the line just attach the gauge on the end of the feed to teh carb and crank it over severeal times and read the gauge. You need at least 5 lbs of pressure.
when at idle and in the drive there is no load no heavy demand for fuel. Also the line I was refering to is connected to the fuel pump samll 1/4 clear hose going from the pump to the throat of the carb. No a safty issue someone has created by adding a plastic inline fuel filter. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Tim D
Date Posted: August-16-2010 at 2:00pm
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Change the power valve in the carb. ------------- Tim D |
Posted By: bmiller
Date Posted: August-16-2010 at 3:04pm
| 79, to answer your question no there is no fuel going through that 1/4" line that your refering dumping into the top of the carb.I am no carb expert in terms of rebuilding them can you please tell me what that power valve does in the carb.Tim your not the first person to suggest the power valve replacement.79 could the power valve also be the problem I'm having if I have the proper fuel pressure that your saying that I need as Tim is suggesting. |
Posted By: 79nautique
Date Posted: August-16-2010 at 3:33pm
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don't agree with the power valve causing the issue at all.
regarding the fuel and 10 ethanol don't see that being an issue either unless your filling up the tank and letting it set for extended periods of time in a every moist enviroment. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: behindpropeller
Date Posted: August-16-2010 at 3:45pm
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How old is the fuel? ------------- |
Posted By: bmiller
Date Posted: August-16-2010 at 3:52pm
| Fuel is not old.I use this boat at least twice a week.The boat never sits unless its winter. I will get back to you about the fuel pressure off the pump as soon as possible. |
Posted By: 71redrocket
Date Posted: August-16-2010 at 8:43pm
| I have a 71 stang with a 302 and am having the same exact problem you are. I bought a new fuel pump and 4160 re-new kit of course with the new carb and spacer gaskets. Im gonna tackle it tomm afternoon my boat does it more often when its underload as well. Sometimes it will run just fine when not in gear. Im pretty sure its the fuel pump but Im not gonna play around and do it all for piece of mind. Oh and the renew kit comes with new powervalves from skidim. |
Posted By: Luchog
Date Posted: August-16-2010 at 9:41pm
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Check the fuel/water separator,
take off fuel bowl from the carb to check for dirt on the main jets. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique Commander 351W |
Posted By: bmiller
Date Posted: August-17-2010 at 12:23am
| Just to get back with an update,I did check the fuel pressure on the pump and it was 7 lbs as you ask 79.As for Tim's suggestion about the power valve and I know 79 thought that it probably was'nt the problem.I did talk with Richard at SKIDIM today an ask there opinion.He also said fuel pump but that doesn't seem to be the problem.He also did say to check the power valves to see if they were blown.He said to turn the mixture screws all the way in to see if the engine dies.If it does then the power valves are good.I tried it tonight and found that the engine does did not die on me which leads me to believe this might be the problem.If anyone else has an comment or suggestion I would sure like to hear it. |
Posted By: bmiller
Date Posted: August-18-2010 at 3:01am
| Just to update,tore into the carb today.Thought the problem was the power valve that was bad.The inside of the metering block assembly is totally ate up.Never seen anything like it.It looks like it got sat in a bucket of battery acid.I have no idea if its the ethanol in the gas or the lead additive that I'm using.I need to rebuild the whole carb. |
Posted By: Whitfield
Date Posted: August-18-2010 at 6:20am
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Any chance of snapping a pic or two of the train wreck?
I'm curious as to why the metering block would be eaten up and even more so how to avoid it happening to me. I'm not familure with the led addative. I've heard it was to lubricate the valve guides on older engines, but no one I know runs it on old stuff. Any chance it is addative related? ------------- Michael .... I'm the black sheep ~ 1984 Dixie 299 Super Skier (350 Chev PCM / counter rotation / Velvet drive) Open Bow. |
Posted By: 8122pbrainard
Date Posted: August-18-2010 at 8:56am
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Brian,
Why are you using the lead substitute? Someone saw you walking in the door and sold you a bottle of nothing! I hope you're not buying Fram oil filters as well!!   ------------- /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: 79nautique
Date Posted: August-18-2010 at 12:06pm
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water sitting in the fuel bowl is what ate up the plate, not the subsitute or ethanol in the gas.
I subspect this boat has sat for some time resently in it's life. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: Bri892001
Date Posted: August-18-2010 at 12:24pm
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Do the renew (rebuild) kits come with new metering blocks?!
At what point to you just go with a whole new carb? Well, at least you know where your problem is. |
Posted By: 79nautique
Date Posted: August-18-2010 at 12:30pm
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metering blocks are available but not part of any kit I've seen. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=756&sort=&pagenum=1&yrstart=1979&yrend=1979 - 79 nautique |
Posted By: bmiller
Date Posted: August-18-2010 at 1:50pm
| Good news guys,contacted Holley Technical this morning and told them what my problem was.I told him that the carb was only 4 years old and what had happened.The guy from Holley wanted the date code and list number and found out that for that carb and the year it was made that they had trouble with bad castings during manufacturing.He said they had alot of trouble and had several carbs from that time period to come back.He told me to box the carb up and send it back to Holley in Bowling Green Kentucky and that they would send me a new carb back to me for free.Problem solve with no money out of my pocket.If any of you guys put 450cfm carbs on your boats around the time period of 2005 just watch out for that potential problem. |
Posted By: Bri892001
Date Posted: August-18-2010 at 1:54pm
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That's awesome news.
Let us know how it runs after you install the new one. |
Posted By: kapla
Date Posted: August-18-2010 at 5:06pm
incredible..only in america...
 ------------- <a href="">1992 ski nautique |
Posted By: 8122pbrainard
Date Posted: August-18-2010 at 6:29pm
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Brian,
That's fantastic news on the carb. Sometimes things do work out for the better. However you'll be with out the boat for awhile. What did they tell you about the turn around time? No opinions on the lead substitute? Maybe my comment about the Fram filter got to you? Don't tell me, you're a closet Fram filter user!! ------------- /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: Bri892001
Date Posted: August-18-2010 at 6:33pm
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Actually, when did boat motors stop needing led? We used to have a 69 starcraft with a 4 banger Chevy, if I'm not mistaken, I think we used to add it.
On Fram Filters, I remember seeing one of those Chopper Shows on Discovery, and this guy had set up a remote filter that was a Fram. I remember thinking the Orange looked really cool against the black color of the bike. I guess that motor was more for show than for go? I know you were talking to the other Brian, but figured I'd fill in. |
Posted By: 8122pbrainard
Date Posted: August-18-2010 at 8:38pm
First you need to know that lead was never meant to be a lubricant for internal parts of your typical engine. Lead was added as a octane booster to gas but it was found to also be beneficial to lubricating valve guides and cushioning valve seats. When the EPA banned the lead from the gas, the chemical companies marketing guys took over and created a lead "substitute" and sold it to the public!!! There is no such thing as a lead substitute and the stuff in the bottle doesn't do any good. I'd like to take a step backwards in time - Marine fuel used to be "white gas". This is straight run gas from the refinery without any additives whatsoever. All the low compression engines ran fantastic on this low octane fuel plus it was the only gas you would find at the gas pier. These old engines ran without any hardened valve guides nor any hardened valve seats. Low octane but no additives!! White gas can still be found as a camp stove/lantern fuel. No additives to plug up the lamp mantels or the stoves orifices. Run the engine and don't spend the $$ on "snake oil in a bottle". When the time comes for a top end job on the engine then you can decide what to do with the guides/seats. Some have chosen not to go with a rather expensive upgrade because their machine shop didn't feel it was worth the extra cost!! All my boats as well as many friends I have though the ACBS have been running unleaded for years without issues!! As mentioned, the other Brian got suckered into buying the stuff!! High mark up/profit for the retailer at the store or at the gas pump dock!!
EDIT: I forgot to comment about the Fram. Do a CCfan search on "Fram" and plenty of info comes up including links to in depth /cut open research on how bad they really are. The guy using the remote filter must have been paid to screw that Fram on there!!! ------------- /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 < |
Bri892001 wrote:Posted By: bmiller
Date Posted: August-19-2010 at 1:52am
| Peter,your cool on the comments.I know when to take a joke.Theres only motorcraft stuff on both my boat and 65 mustang sitting in my garage.I use the lead substitute just like you said Peter.I still have the soft seals in the valve train.This engine has never been touch internally so if it ain't broke then don't fix it is my motto.Shipping the carb out on 8-15-10 by 2 day priority mail.The guy at Holley said by late to mid next week to get a new carb.Its worth the wait if it doesn't cost me anything! |
Posted By: eric lavine
Date Posted: August-19-2010 at 10:06am
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I think the Fram people use the same marketing people as do the Jiffy Lubes....change your oil every 3000 ------------- "the things you own will start to own you" |
Posted By: 71redrocket
Date Posted: August-24-2010 at 8:48pm
| Update on mine I did the carb re-new kit and fuel pump in mine and shes running like a scalded biatch now. I had the same problem once I opened the carb the power valves were shot along with some other stuff. In the future if the boat sits for a period of time I will drain the bowls. |
Posted By: Bri892001
Date Posted: August-25-2010 at 12:37pm
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71RR,
How hard would you say it is to do the carb renew kit? My boat has a hesitation and I'm on the fence between doing a renew kit or getting a whole new carb. I know I could remove and replace the carb without much trouble. So, I was thinking it would make sense to just replace it for a little extra verses paying someone to rebuild it. Would you put rebuilding it at a beginner level, intermediate, expert? The more I read about 4160s, the more complicated it looks. Do you need and special tools or chemicals? |
Posted By: 81nautique
Date Posted: August-25-2010 at 12:51pm
Just caught this thread, I had the exact same problem with a new 600 Holley about 4 years ago, too much lead in the casting was what Holley told me. My bowl was breaking down and the flakes were preventing the needle from closing causing flooding. Replaced with a brand new unit no charge also. Been running beautifully since. ------------- You can’t change the wind but you can adjust your sails |
Posted By: bmiller
Date Posted: August-25-2010 at 5:02pm
| Just got the New carb from Holley yesteraday.I plan on putting it on tonight.Will let you guys know what happens.Just for your information,Holley sent me a notice in which you can go on the interent at www.holleytv.com.It gives you a video guide on how to tune your carb.It shows you everything you need to know.When you get to the site just click on "carb tuning" and it has multiple videos on what you need to know when tuning your carb. |
Posted By: Luchog
Date Posted: August-25-2010 at 9:18pm
describe your issue? ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=2095" rel="nofollow - 1980 Ski Nautique Commander 351W |
Posted By: Bri892001
Date Posted: August-26-2010 at 2:15am
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My issue is like a stumble when you try to accelerate quickly. It's mostly off idle, but I've noticed it can happen when quickly accelerating from one speed to a higher speed, even from 1500 rpms or so.
Full throttle is fine, and if you accelerate easy, it's fine. If you punch it though, such as to get a big slalom skier out of the water, it will hesitate, if it's not totally warmed up, it can hesitate pretty badly. Also, idles and starts up hot and cold fine. |
Posted By: 8122pbrainard
Date Posted: August-26-2010 at 8:50am
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Brian,
Pull the flame arrestor, look down the throat of the carb (engine not running), advance the throttle linkage and look for a squirt of gas. If none, then it's the accelerator pump in the carb or it's linkage that needs work. ------------- /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: Bri892001
Date Posted: August-26-2010 at 10:51am
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Thanks Peter,
I've checked for a squirt, and I do get one. But it could be that it's coming in late. I haven't gotten a chance to adjust it or look at that aspect of it carefully. Aside from adjusting the little spring thing that hits the pump lever, which is still a possibility, are there are other adjustments that can be made? Any other aspect of the carb that could be at fault? Would a faulty power valve do this? |
Posted By: 81nautique
Date Posted: August-26-2010 at 11:59am
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Bri892001, You've got a stumble at throttle up and a stumble after 1500. 2 totally different issues. Before messing with the carb ensure that the motor has a fresh tune up, new cap, rotor, plugs, etc.
Don't adjust the accel pump and it's not your power valve. I suspect timing and tune up, just verify that everything tune up wise is good first then post back and we'll look at the carb. ------------- You can’t change the wind but you can adjust your sails |
Posted By: Bri892001
Date Posted: August-26-2010 at 12:33pm
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I do have new plugs, wires, cap and rotor (mine is not a points type, it's a prestolite with the electronic ignition). Also, a new fuel filter, the inline type mine doesn't have a water separator.
Doing the above tune up did improve the overall performance a little. The boat got a little more power and a slightly faster top end. It seemed to make the stumble a little less, but didn't make it go away. The timing is a little suspect. It's advanced to 13 degrees, but bringing it back to the recommended 10 seemed to worsen matters. Actually, correction, bringing the timing back to 10 degrees worsened matters before I replaced the spark plugs and everything. And, I had a wacky assortment of different plugs in there previously, as mentioned here: http://www.correctcraftfan.com/forum/forum_posts.asp?TID=18737 - Different Plugs Post Do you think that now that I have the right plugs, bringing the timing down to 10 degrees might improve things? |
Posted By: bmiller
Date Posted: August-27-2010 at 1:08am
| Jusy to let you guys know.Took the boat out tonight for a test run and it runs great.Alls well and time to go boating.Thank god Holley steped up to the plate and admitted there mistake. |
Posted By: 71redrocket
Date Posted: August-30-2010 at 11:40pm
| As far as doing the carb myself I knew a guy who did it for me. I brought him carb and kit for $70 he rebuilt, glass beaded the inside and painted for a true professional job. So kit and labor I was into it for 120 compared to 500 brand new. I did fuel pump to just to take care of almost all fuel delivery. I would pay to have it done rite all day if you dont know what your doing. Check your fuel water/separater if havent done yet. |
Posted By: Bri892001
Date Posted: September-08-2010 at 1:40am
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Hi guys, I found the cause of my hesitation as well and fixed it.
It was the accelerator pump. I was getting a squirt, so I though that the Accelerator pump was fine, but it turned out there was too much play in the linkage. I adjusted the little bolt, spring deal on the pivot to take up the slack now. It works great now! Takes off like a champ, it really made my weekend. |