Crude Intentions

Brian sounds strange. I know motors are fresh. Are you sure timing and firing order are right? 2 different carbs and roughly same rpm tells me it isn't fuel related but maybe timing related. When I bought mine it felt good but I couldn't get port motor up to rpm. Began troubleshooting, found firing order wrong. Corrected firing order and boat wouldn't start. Really scratching head now. Checked dizzy and it was 180 out. Just a thought. Couldn't hear it at idle and boat came up to 3200ish ok. Just no more.

befu

I believe you are on the correct path for mine. The carb was definitely an issue from National. next week first on the list is to fix the wheel bearing. Then it is to pull plugs and look at them. Do a compression test once the plugs are out. then redo all the spark plug wires to be sure they are correct. It is amazing how you can check the firing order and a twist in the line will cause you to make the same mistake every time. Then another water test.

After that, we will swap carbs side to side and see if problem follows carb or stays with engine. We also have a third HEI unit we can put on it just to be sure we are not working with a faulty unit. Bewtween the plugs, wires, dizzy, carb and compression test, I think we will get it sorted out soon.

On another note, I thought my trim indicators were way off. When I set my drives to just trimmed out a bit, it is amazing how much the bow lifts and falls in a 1' chop at 35 mph. I thought I was trimmed up too far, but almost level. the four blade props must have a good amount of bow lift.

befu

Wow, been almost a month since my last update. Been way busy at work with a labor/burden/cost restructure I have been working on for the past 3 months. finished that yesterday, went boating today!

So we did a compression test a week ago on that SB motor and found 3 dead cylinders, as in 0 on compression. Pulled the valve covers, hooked up the flow meter and backed the rocker nuts off. Yep, three valves were too tight and never closed killing 3 cylinders. Adjusted properly and the compression numbers came right up to 165 to 175 across all 8 except cylinder #6 which was just over 160, a bit low. I sent the carb back to National and last week I received another one from them. The dang linkage bracket was bent way over, so I had to fix that before putting it on the boat. Between the 3 extra cylinders I have now and a working carb, power definitely was better but I still have a drop when I hit the start of the secondaries or 3500 rpm. Not sure if it is carb or dizzy. If I just push the throttles forward, SB motor bogs down to 2300 rpms for about 3 seconds and then EXPLODES and jumps in power to 4200 with the other motor. I mean comes on and pushes you back explodes! Wow, what a feeling that is. now I need to figure out why. I am going to swap carbs and see if the problem stays or follows the carb.

I am still running the 4 blade aluminum solas 21" pitch props. They really like to lift the bow, I mean a lot! With about 1-2 degrees of up trim, 3200 rpm the boat will run nice with the bow just oscillating up and down like you are running in a 2' chop. Kinda fun on an inland lake actually. This week I may try to put my 23p Laser II on it and see what it does. At WOT after the bog passes, the motors spin 4200 rpm and speedo was showing 40 mph. Seemed like more, didn't check gps. Ran like this for about a mile and then idled by a sandbar. While running, I tried to trim up the drives for more rpm, but looking at the prop wash, it looked bad. I mean more like a fountain than prop wash. I think these Solas props are just not made to push this big heavy boat too fast. The good news is with the bennet tabs dropped and the drives tucked in, the boat will plane out easily at 16 to 17 mph. That is pretty dang slow to be pushing a 6,000 lb boat around with 1/3 tank of gas and 5 people aboard with 2 more in the tube behind it. I am really happy with the low speed performance.

Lost my train of thought, drink hit my mind hard now. Will read my own post and respond to it........

Brian

befu

So anyways, today was a big day. I actually took my wife and 5 kids (2, 7, 9, 11, 13) out boating. The engines fired right up once in the water, idled and shifted well. Restarted when shut off due to loading and unloading of tube which is a really good feeling when drifting in the lake. We ran around some, went to sand bar and swam, then tubed and did anther fast run around the lake. Kids had a lot of fun and the wife enjoyed the boat time which was REALLY important to me. Went really well and was a good boost for my moral.

I need to figure out that bog in the starboard motor and work on the top speed. I now own the slowest 600 HP performance boat in the state of Indiana I think.... But the fact that the trailer works great, the motors start, idle and shift is huge to me. I want to run it another 3 or 4 times before cold weather hits and I have to put it away, but am also looking forward to anther winter of projects and finishing more of the boat for next summer. If it is still running fin this fall, it will be a nice feeling to be able to think of putting it back on the water when things warm up enough in late April or early May.

Gotta figure out that SB motor now...

Brian

FIXX

the bog going into the secondaries is from the top butterfly opening too soon,,that is controlled by the choke pulloff,,if the engine loads up when you first start it when its on choke then the pulloff is not working..how it works is when you start the engine the vacuum pulls the choke pulloff closed and also holds the secondary upper butterfly rod closed,,when you apply throttle and ease into the secondaries the engine loos's vacuum and that when the upper butterfly opens and lets the fuel past the metering rods which lets the fuel into the engine..if the choke pulloff is not working it lets the secondary butterflies open too soon and dumps too much fuel in creating a major bog..hope this helds..

befu

Yeah, that does help, thank you for replying. I had someone else tell me it was carb related which I was hesitant to believe as it has done this with three carbs on it. But what you say does make sense. The carb might be OK, but I wonder if I have an intake valve issue on #6 which might cause an erratic vacuum causing any carb to do the bog thing. Once it is past that bog, it does run well. I think when I get time I will do another compression test dry and wet with some oil on the rings. see if compression goes up any or if it is low due to a valve. leak down test will tell me if it is exhaust or intake. Will also put a vacuum gauge on that motor and see what the needle is doing. I used to know how to read a dang vacuum gauge, but haven't worked on a carbed engine before this boat in a long time, about 20 years!

It is easy enough to swap carbs also to see if the problem follows the carb or stays with the engine which will tell me it is internal. If it is not valves, I will just live with it until the new 355's are ready. Planning to go out Wednesday again.

Brian

sprink58

Brian,

Remove both fuel lines from the tank, dis connect the right angle hose barbs and remove them. Take them apart and observe the condition of the spring and ball check. I suspect that yours are like mine...totally crudded up. This will restrict your fuel flow as you have described. I am replacing mine...$15-$20 ea at West. You could also just knock out the entire check/anti siphon assembly and re-install but I don't recommend it. These old boats gather a lot of crap in the fuel system over the years and when you have 5.7 litre engines trying to suck 50 GPH thru a straw...that straw needs to be free of obstruction.

Give it a try.

befu

Ran it again today. We checked everything over, put some new fuel in it and switched the carbs around to see if the problem followed the carb. And it did. Sure enough, it runs nice up to 3200 rpm or so, but as soon as you advance into the secondaries, the engine bogs and then revs. Problem is definitely the carb, the starboard motor ran great this time, the port motor was bogging. Even when running faster, if you drop the throttle it will enter the bog again. I could also get it going to where it would surge and stumble if the throttle was dropped slow enough to the right spot. Run strong, then bog, then run strong again.

Below is a short video of one of the transitions. At 4 seconds I advance the throttles and by 6 seconds it is speeding ahead. All I did was advance the throttle into the secondary range and then leave it there.

this is the national carb that I had to send back due to the bottom screws not being tight and it leaking fuel. Once I tightened up the screws, it stopped leaking but had the bog. Sent it back, waited about a month and they sent it back no charge, said they fixed it. Well, it isn't leaking but it is still bogging. Going to have to call them and see if I can get it fixed correctly this time.

http://www.youtube.com/watch?v=Wb1Qc...ature=youtu.be

befu

The next problem will be my props. I will have to post in the prop section for that also, but today I tried my Stainless Laser II – 23p props for the first time. First, the boat got on plane incredibly easy! No tabs, drives just below neutral not even in all the way. Advanced the throttle and she just walked up on plane, very little bow rise. I was happy.
But then once it got up to speed, I started trimming out the drives. And trimming. And trimming. I was almost at the limits of the trim switch and the boat still would not lift the bow. It really felt like it had the bow planted. If I took the wheel and lightly moved it side to side, the bow stayed planted and the stern felt like it was floating back and forth. I wondered if this is what it felt like before boats spun out, so I didn’t push it. I was going about 35 to 40, but was amazed at how light the stern felt.
On my 4 blade – 21p aluminum props, a couple degrees over neutral trim and the bow would lightly porpoise. This time I couldn’t get the bow out of the water until it was back on the trailer. I thought the Laser II’s were supposed to be bow lifting props also.
So the video is a short segment of when we were running, maybe 35-40 mph? rpms were at 4,000 rpm, drives were trimmed up, not tucked in, tabs up. Didn’t feel real nice.

http://www.youtube.com/watch?v=TCZIm...ature=youtu.be

Crude Intentions

Glad it's coming together Brian. I have some standard 3 blades.....damn can't think of brand. She rides nice and definitely responds to trim. Stiletto. Think mine are stilettos. 21 if I remember right. Haven't looked at my props in a while but did a lot of research propping the fishing boat so I have alot of brands and numbers in head. Lol