351w Timing, Igntion & Overheat - Q&A |
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LeftFieldEngineering
Senior Member Joined: December-20-2010 Location: Monson, MA Status: Offline Points: 384 |
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The new engine didn't come with a circulator pump, I opted for a new one over my used pump and purchased a new one from ebasicpower. It was ordered and looked to be a bi-directional pump.
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DayTony
Gold Member Joined: June-30-2013 Location: Salem MA Status: Offline Points: 831 |
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this may sound stupid, but are your mufflers rotated correctly?
I just put my exhaust back together just right now and was getting about a 20 degree difference between the port and starbord side. i noticed the port muffler was rotated a bit sideways. i indexed it correctly and both sides are now perfect. just a thought. one more thing to be certain of. |
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1988 Barefoot nautique-454
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LeftFieldEngineering
Senior Member Joined: December-20-2010 Location: Monson, MA Status: Offline Points: 384 |
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I applicate the help, you never know which of the small details will lead you to the answer. As for my mufflers I'm pretty sure they are in the right orientation, they have 45 deg elbows molded right into them so they're pretty hard to not put in right..
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DayTony
Gold Member Joined: June-30-2013 Location: Salem MA Status: Offline Points: 831 |
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haha roger that. mine, as you know are just straight.
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1988 Barefoot nautique-454
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8122pbrainard
Grand Poobah Joined: September-14-2006 Location: Three Lakes Wi. Status: Offline Points: 41040 |
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I have to ask why? |
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gun-driver
Grand Poobah Joined: July-18-2008 Location: Pittsburgh, Pa Status: Offline Points: 4112 |
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I'm talking about the water pump mounted to the front of the motor not the raw water pump with the rubber impeller. Just to clairify which pump we're talking about. |
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DayTony
Gold Member Joined: June-30-2013 Location: Salem MA Status: Offline Points: 831 |
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The real question should be "why not?" I was mistaken about my engine running an oil cooler, the oil cooler i have runs to the gear. I don't know why i thought that. But most marinized engines I have seen run an oil cooler and i don't see any problem using them. |
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1988 Barefoot nautique-454
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LeftFieldEngineering
Senior Member Joined: December-20-2010 Location: Monson, MA Status: Offline Points: 384 |
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Yes, the circulator pump is the one I replaced with a new marine bi-directional unit. |
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Bri892001
Grand Poobah Joined: September-27-2008 Location: Boston MA Status: Offline Points: 4947 |
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I'll throw an idea out there. I know you said you replaced all of your hoses, but are they wire reinforced on the suction side?
Either way, see if you can have a buddy take a look under the engine cover while at speed and make sure nothing is collapsing or making any funny kinks or bends while under high rpms (high suction) |
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LeftFieldEngineering
Senior Member Joined: December-20-2010 Location: Monson, MA Status: Offline Points: 384 |
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I'll admit only 90% of my raw water intake system is reinforced hose. The other 10% is made up clear vinyl hose that is not suction rated. Why would I knowingly use it?
A.) I didn’t want to cut up my good hose when installing the Timmy T flushing hookup between the thru-hull and the strainer. B.) There isn’t much room in the Tique so after all the flushing parts are installed there isn't more than 1-2” between fittings so I went with the clear stuff. I did try to collapse a test piece with pliers and couldn't get more then 1/8" deflection. C.) I wanted to see how good the flushing system worked so having small sections of clear hose work as an in-line sight glass. Obviously it will be checked tomorrow on the lake. I would love nothing more then to be wrong. |
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Bri892001
Grand Poobah Joined: September-27-2008 Location: Boston MA Status: Offline Points: 4947 |
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Sounds like you've put thought I to that aspect anyway.
Make sure you haven't inadvertently built any restrictions into your flushing set up as well. Another thing I'd be interested to know, when your engine is in an overheated state, are your exhaust risers super hot as well? Just wondering because those are cooled more directly by you RWP and should Edit: NOT be temperature dependent on your Circulation pump and t-stat. |
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GottaSki
Grand Poobah Joined: April-21-2005 Location: NE CT Status: Offline Points: 3336 |
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I'm Still suspect of the tstat.
Some are highflow. Some don't flow much at all. and, it is oriented correct, yes? |
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"There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing."
River Rat to Mole |
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LeftFieldEngineering
Senior Member Joined: December-20-2010 Location: Monson, MA Status: Offline Points: 384 |
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It's something to keep an eye on, though I did follow the instructions outlined in this thread Advice for reviving a '87 SN 2001 after 10yrs for building the flushing adapter.
As for the risers: I can normally hold my hand on them and they IR temp out at 120-140ish. After the barefoot run I can touch them for a little bit, but they are hot (like 180-200). The exhaust hoses are pretty consistent so I though it was just the extra heat from running at higher rpms for 4-5 min. Also I tested it again yesterday off the hose and I was getting 145 deg at the thermostat to water pump neck. The water coming in was so cold it had condensation on the top of the t-stat cover and on the risers. When I ran it up to 3000 rpm for a few min the t-stat to pump neck reading would go up to 150 then drop down to 135 (I assume that’s the t-stat opening) Oddly enough though the gauge would hover right at 160-170 ish. Ignoring gauge discrepancy I wonder if I’m just getting an air pocket at the top of the intake where the t-stat and temp sender are located. As I mentioned before I had disconnected the lower (return) heater hose from RWP line, but I did leave the upper hose attached to the intake. Each of my heater hoses have ball valves so one of my tests tomorrow is going to be to open the upper heat hose ball valve, if it bleeds air out I know I’m drawing from somewhere. If it’s just water I can try to get an actual temp reading from the intake water. |
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LeftFieldEngineering
Senior Member Joined: December-20-2010 Location: Monson, MA Status: Offline Points: 384 |
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Me too. I mean it's a new t-stat, but you never know. For that reason I did dig out my original last night. If I don't see any improvements tomorrow I plan on pulling the "new" t-stat , test both of them on the stove and put the old one back in. As far as I know it's in there right, the spring side is down into the water. |
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Hollywood
Moderator Group Joined: February-04-2004 Location: Twin Lakes, WI Status: Offline Points: 13512 |
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If the risers are hot the t-stat is not the problem. A stuck open t-stat will keep the engine cold and a stuck closed t-stat will heat up the engine but the risers will be cold.
Get 2 garden hoses. Hook one up to the t-stat housing where the RWP usually supplies the engine. Do a bucket test with the other and monitor the RWP output as well as engine temp. If you only have 1 hose then go back and do a bucket test with a new long hose from bucket directly to the RWP. You've got a lot of connections going on in a tight space. |
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MrMcD
Grand Poobah Joined: January-28-2014 Location: Folsom, CA Status: Offline Points: 3605 |
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I see the struggle goes on with your overheat issue but only when working it hard.
I read advice in this thread on setting your timing. I read your settings at idle but I never saw what your timing is at speed. Total timing is the timing achieved when the distributor is fully advanced. Most are fully advanced somewhere between 2,800 and 3,500 RPM. You need to find out how much timing you have when the distributor is fully advanced,. It should advance smoothly from idle to the point where it is all in. Once it stops advancing run it up another 500 RPM just to make sure you have a good reading and it really has reached full advance. Timing lights are available with a dial back setting or you can buy timing tape at a speed shop that you can apply to your damper to allow reading the timing all the way to 45 degrees. Marine distributors are famous for rusting the weights inside the distributor that control your advance. Some stick and don't advance. They can be cleaned and greased and returned to normal operation for no cost usually if you do the work. Total timing is far more important to good engine performance than timing at idle. Determine your total timing and set it at 34 to 36 degree's. Your idle setting should be close to the factory recommended setting when the total timing is correct. Once you determine how much advance your distributor gives you it will be easy to set the idle Timing. If the distributor gives you 24 degrees of advance you can set your idle to 10-12 degrees and know the total timing will be 34-36 and all is good. IE: 10 + 24 =34 degree's total advance. If you don't get similar numbers your distributor will need attention. Too much advance will make it run hot and can cause engine damage and pinging on acceleration. Too Little advance can cause it to run hot and have weak performance. Both are bad. You really need to know how yours is performing before chasing other issues. If your weights are rusty and sticky they can give you many operating issues. I hope you get dialed in soon, Ski Season is Now! |
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LeftFieldEngineering
Senior Member Joined: December-20-2010 Location: Monson, MA Status: Offline Points: 384 |
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Update:
1st off, A+ for National Carburetor. My re-man carb came in at 5:30 last night and it is a thing of beauty. I mean I know how it looks has nothing to do with how it works, but I was pleasantly surprised to find a polished aluminum carb that looked more like brand new then a re-man. Anyway, I bolted it on with my new flexible fuel line and gaskets from Skidim and SOB if it didn't fire right up after priming. I've never heard anything like it, it was quiet, ran great and Idled down to 400 rpm (didn't even know the engine would run that slow, but I adjusted it back to 500-600). More amazing was the performance at the lake this AM. I mean I was happy with the performance before, but now it's like a whole new boat. Lake test: 5:30am I fired up the boat and we made a run across the lake to pick up our 3rd. The boat seemed normal, ran at 150-160 the whole time. We picked up our third and headed out for the first glass smashing barefoot run of the day. My buddy kicked a ski and we were off. Just like before the boat ran hot after a few min. At full bore (45-46 mph) we were pushing 4300 rpm. Spec'd out at 4400 rpm max, 4300 rpm was too close for comfort so I backed off to 38 mph. Again just like before once we slowed down the temp dropped back to normal. After our barefoot run we pulled the engine cover and made another 45 mph run watching the clear section of the water inlet. No real bubbles to speak of, nothing more then I get running off the hose in the driveway. Getting back to the 4300 rpm speed. The boat came with (to me) a 12RH14 prop however I did pick up a 12RH15 to have as a spare. The fog rolled in this AM after our barefoot run so we pulled the boat & swapped props at the ramp. You want to talk about a different boat? I mine as well use the 12x14 as my anchor because that thing is NEVER going back on the boat. We made a 50.2 mph run (GPS confirmed) before we started porpoising and the boat had only gotten up to 3900 - 4000 rpm. We then cruised around at 41-45 mph (3200-3400 rpm) and guess what? Temperature stayed at 160-170. MrMcD: As soon as I get my hands on some timing tape or an adjustable light I will get that checked out. Currently I'm running off base time and the fact it does not (and has never) pinged. I plan on picking up a new timing light tonight. |
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Bri892001
Grand Poobah Joined: September-27-2008 Location: Boston MA Status: Offline Points: 4947 |
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It's interesting that the overheat problem seems to be correlated to RPM, not necessarily to speed or to engine load.
This gives me another idea. Occasionally, impellers can fail (or be defective out of the box) in such a way that the metal part that keys into the shaft will spin freely of the rubber outer part. When I say spin freely, not necessarily "freely." Just that, with enough resistance, there will be some slippage. |
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MrMcD
Grand Poobah Joined: January-28-2014 Location: Folsom, CA Status: Offline Points: 3605 |
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It sounds like you are using the boat and having fun. Good for you.
Glad the carb worked out so well. I had a 78 Nautique from 82 to 1991. I turned a 13 x 14 prop and loved it. The boat would cruise 40 MPH at about 3,500 RPM and did a little over 50 easily. I had pumped up the engine a little, raised the compression and ported and polished the heads but it ran nearly as fast before the new heads went on and I never switched to the 13x13. I loved the 13x14 on that hull. We did a ton of Barefooting and preferred it to the 1983 Nautique my buddy had. for barefoot runs. He did a lot of one foots and mine pulled over 40 MPH without hitting the 4 barrel. The only time mine ran hot was when the impeller was due for a change. Other than that it sat on 140 all the time. The owner of West Coast Correct Craft used to be on the lake with us and he always had a 454 powered boat. He could pull out more skiers but he could not outrun us as we crossed the lake getting to the ski area's. Used to tick him off. I loved it. |
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80SN Barnfind
Senior Member Joined: December-13-2010 Location: Niagara River Status: Offline Points: 122 |
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Tony, real quick so as to not hijack the thread, you mention indexing the muffler and I'm wondering what the proper orientation is? I posted this same question to the forum a few years back and never got a definitive answer. Here's a shot looking down the end of one of mine; Which way is up? |
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Knowledge comes by taking things apart: analysis. But wisdom comes by putting things together.
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Gary S
Grand Poobah Joined: November-30-2006 Location: Illinois Status: Offline Points: 14096 |
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That is the correct way,opening down so that the water drains out. If you had the opening at the top water would collect ,making your exhaust pipe smaller too. Could also freeze if left in there.
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DayTony
Gold Member Joined: June-30-2013 Location: Salem MA Status: Offline Points: 831 |
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yes you want it to naturally drain or you will quickly fill your engine with water. The orientation i was asking in my thread before was which direction the flow wanted to go through the baffles. I decided to run it with the side you pictured facing the engine. i don't know if that was right or not but it seemed to work well.
Andy good to hear you've got it going good now. what cfm is the new carb? |
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1988 Barefoot nautique-454
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LeftFieldEngineering
Senior Member Joined: December-20-2010 Location: Monson, MA Status: Offline Points: 384 |
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600 cfm, direct replacement for the one that was on there.
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Bri892001
Grand Poobah Joined: September-27-2008 Location: Boston MA Status: Offline Points: 4947 |
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Andy, I think you just drove by me. I'm watching my nephews t ball game at the field by the Holland Police Station.
It was getting (staying haha) boring. I was like, whoa, CorrectCraft... that's a Tique... I think I know what one. I snapped a pick to prove it; I'll upload it later. |
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LeftFieldEngineering
Senior Member Joined: December-20-2010 Location: Monson, MA Status: Offline Points: 384 |
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Caught me .
We were heading to a different lake after our morning spot filled up with fishing boats. If your in the area again and want to come out for a ski. |
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Bri892001
Grand Poobah Joined: September-27-2008 Location: Boston MA Status: Offline Points: 4947 |
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My brother lives right out there in Brimfield, so I'll definitely shoot you a line next time I'm out there. Hope you had a good day at the lake, it was definitely nice weather today despite it being a little overcast.
Here is the proof |
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