Hard starting Yamato 102

[BillCNC]

It's a go for tomorrow. It fired right up as soon as the fuel was in the carb. I ran it with water for a few minutes and played with the throttle at different rpm's, nothing very high as I dont have a test wheel.

The needle height remained unchanged.

Problem of running out of fuel, ... solved!

Now to get the sponson's out of the water a little further, ...

[Aussie Steve]

Hope it goes well mate I will be waiting to hear .

[BillCNC]

Well, after testing, there was good news and bad news.

VIDEO; http://youtu.be/afMYiRdUUqk

In the video, we were in a secluded cove were the wind was minimal. The lake got blown out about 15 minutes later and we left. I was in a giant turn for most of the video, but the beginning were I am going straight, you can see the front is still not lifting like it should.

Good News,

The starting issue is completely gone. She fires up first pull even with the motor having sat for 15 minutes out in the lake. If it didn't start on the first pull, it was because the kill switch clip was not installed. In fact, it was the joke of the day. I started and purposely stopped the engine in the water just to make sure the issue was resolved and it was. The Fuel pump worked flawlessly! The best thing I have done to the boat so far is adding the fuel pump, considering we went through 2 gallons of fuel today.

Thanks guys for helping me with the starting issues, ... I REALLY appreciate it, ... BIG TIME!!!!!!!!

I pulled the plugs and had a look to see how they were doing. The bottom is a nice reddish tan but the top plug was darker in color.

Question:

I am using #10's for the plugs because I was using an 18mm head with inserts, ... Now that I am using a 14mm head without inserts, should I go to a hotter #9 plug?

Plugs are pictured. The one on the left is from the bottom cylinder.

Now onto the bad,

It seams that the Nylon blocks for adjusting the motor tilt were a bit to much. The blocks I made were to the thickness that the original stack would have been BEFORE the wearing is a bit to much. I had a real hard time getting up on plane. It seems the prop was cavitating pretty bad. I had to feather the throttle for quite awhile before I could get the prop to grab the water. We took the boat in and I removed the .125" aluminum transom cap dropping the motor height by .125". It helped but I it still takes a bit of laying down on the bow to get her to plane. I dont think my engine height is to much because I have always had excellent water flowing from the two hoses coming from the exhaust even during high speeds.

Here is some video my son took from the chase boat. I don't think the front of the boat is lifting as much as it should be. In fact, I dont think I changed any of that much. At the beginning of the video, you can see it might have lifted slightly, ... but nothing like your boats.

Question,

Anyone have any ideas on how to get the front to fly?


NOTE:

I understand I didn't have a helmet and I didn't have a very good life jacket, ... but that's next on the list, ... PRONTO! I let my oldest son (26) drive it and he had a BLAST!!!!! He's thinking about getting a Hydro also so we can race around the lake together. We even talked about making or getting a couple modern Hydros and possibly racing them. His wife isn't to keen on the idea, ... but that's something he needs to work on, ...

Regards
Bill

[johnsonm50]

I watched the vid & stopped it in a couple side profiles to see where you were. The 1st thing I'd try is to get your weight further back. you'll find if you go hard in a turn the fin will grab well with weight forward.. thing is it can grab a little too well & spin out the boat as the motor skeg fails to hold. This can be a minor correctable deviation or major enough throw you out. Its a matter of balancing the boat out by where your weight is &/or tilt. If getting back wont allow the lift then gradually tilting, [probably out] should do it. Motor depth can play a part too as well as prop choice. Not planing easily is sometimes how it goes. some props will go on plane better than others. When they do lift you'll notice a little bit of rocking side to side probably. Be cautious with lift at 1st as 'too much' fun can occur. Good Luck. Mike

[BillCNC]

Mike,

I was under the assumption I should be hugging the steering wheel an I never once thought about sitting further back once I was at speed. Sounds like I have absolutely no clue as to what I am doing, ... thank god for this forum, ... I don't know what I would do without it!!!

The trouble with doing a bunch of things all at once to correct issues, is that you don't get to see the differences the individual changes make. Lost a little bit of education but something tells me I will find out what they individually do all in good time.

I think I'm going to make some new Nylon tilt blocks to the worn dimension and see what that does. It got up on plane fine the first time I took it out before I cut the transom down a tad as I would really like my .125" aluminum transom cap back on, removing it left the top of the transom paint carved up.

I want to try to take it out one more time this year, let
s just hope the weather will cooperate. I'm going to pull the gear foot and change the oil. What is a good oil to use?

Thanks
Bill

[mercguy]

Well, after testing, there was good news and bad news.

VIDEO; http://youtu.be/afMYiRdUUqk

In the video, we were in a secluded cove were the wind was minimal. The lake got blown out about 15 minutes later and we left. I was in a giant turn for most of the video, but the beginning were I am going straight, you can see the front is still not lifting like it should.

Good News,

The starting issue is completely gone. She fires up first pull even with the motor having sat for 15 minutes out in the lake. If it didn't start on the first pull, it was because the kill switch clip was not installed. In fact, it was the joke of the day. I started and purposely stopped the engine in the water just to make sure the issue was resolved and it was. The Fuel pump worked flawlessly! The best thing I have done to the boat so far is adding the fuel pump, considering we went through 2 gallons of fuel today.

Thanks guys for helping me with the starting issues, ... I REALLY appreciate it, ... BIG TIME!!!!!!!!

I pulled the plugs and had a look to see how they were doing. The bottom is a nice reddish tan but the top plug was darker in color.

Question:

I am using #10's for the plugs because I was using an 18mm head with inserts, ... Now that I am using a 14mm head without inserts, should I go to a hotter #9 plug?

Plugs are pictured. The one on the left is from the bottom cylinder.

Now onto the bad,

It seams that the Nylon blocks for adjusting the motor tilt were a bit to much. The blocks I made were to the thickness that the original stack would have been BEFORE the wearing is a bit to much. I had a real hard time getting up on plane. It seems the prop was cavitating pretty bad. I had to feather the throttle for quite awhile before I could get the prop to grab the water. We took the boat in and I removed the .125" aluminum transom cap dropping the motor height by .125". It helped but I it still takes a bit of laying down on the bow to get her to plane. I dont think my engine height is to much because I have always had excellent water flowing from the two hoses coming from the exhaust even during high speeds.

Here is some video my son took from the chase boat. I don't think the front of the boat is lifting as much as it should be. In fact, I dont think I changed any of that much. At the beginning of the video, you can see it might have lifted slightly, ... but nothing like your boats.

Question,

Anyone have any ideas on how to get the front to fly?


NOTE:

I understand I didn't have a helmet and I didn't have a very good life jacket, ... but that's next on the list, ... PRONTO! I let my oldest son (26) drive it and he had a BLAST!!!!! He's thinking about getting a Hydro also so we can race around the lake together. We even talked about making or getting a couple modern Hydros and possibly racing them. His wife isn't to keen on the idea, ... but that's something he needs to work on, ...

Regards
Bill

Bill, first off, seldom (if ever) should the motor be "kicked out" (rear of prop shaft higher than front of shaft). A good baselline to start is 1/8" kicked under (rear of shaft lower than front of shaft). Second, you need to move back in the boat after you get it on plane. Use your body motion to adjust the proper attitude of the boat. Planing on depends on the prop and setup and with the motor kicked out, you will have a harder time doing so. You only need to move forward in the boat to "set" the turn fin when turning or maybe in a rougher water condition or windy condition...............get in the back of the boat and "let it fly, BUT FIRST, get the appropriate safety gear, as if you do eventually get pitched out of the boat, you always have a VERY good chance of being hit by the prop, which will definately cause SERIOUS injury!!! Atleast get some kind of helmet to protect your melon!!!

B9EGV or BR9EIX plugs, will do you well, but 10's will work fine also for your use......

[johnsonm50]

I agree on the safety gear, I was recently ejected from a nasty spin in traffic.. the suit & helmet was suddenly very comfortable. I mentioned the tilt should possibly be out more, that meaning if it was in too far but should have clarified that generally tucked some is where you want to be. Your right about the 1 at a time change thing, a note book with what change was made, conditions etc. will help.

[Wagneracing06]

It has to be timing.

Finally someone said timing. The whole time I'm reading through all of the posts, I'm thinking that his magneto plate has shifted to a position that his points are opening too late. It will move in the direction of the engine rotation.There is no power when the motor is started and running because you've gone beyond your compression cycle and then the plugs are firing. I didn't have the mag locks on my motor and I had to keep checking to make sure that my stop screw for the spark advance was against the stop. My temporary fix was a zip tie locking the mag stop screw against the stop. Good luck. I hope you remedy this problem and I encourage you to start racing. You'll have fun and learn quite a bit while participating.

Rick Wagner Sr.

[Tom Cronk]

Mag locks

I have Brown mag locks for $20.00 pr, plus shipping.
Tom Cronk
863-665-5449
tcronk@tampabay.rr.com

[S Henderson]

plugs

I know the thread has moved on but boys and girls we still have problem
with the power head. Those plugs should look almost the same in color. Don’t like that top plug. What do you think Bill Van or Daren.

[krazy karl]

Finally someone said timing. The whole time I'm reading through all of the posts, I'm thinking that his magneto plate has shifted to a position that his points are opening too late. It will move in the direction of the engine rotation.There is no power when the motor is started and running because you've gone beyond your compression cycle and then the plugs are firing. I didn't have the mag locks on my motor and I had to keep checking to make sure that my stop screw for the spark advance was against the stop. My temporary fix was a zip tie locking the mag stop screw against the stop. Good luck. I hope you remedy this problem and I encourage you to start racing. You'll have fun and learn quite a bit while participating.

Rick Wagner Sr.

A bungie cord wrapped around the handle and secured to the gas tank bracket works real well for lake use. Allows you the start the motor retarded and idle off shore out of the 5mph zone and then push to full advance. The bungie cord will keep it in full advance position.
kk

[bill van steenwyk]

A bungie cord wrapped around the handle and secured to the gas tank bracket works real well for lake use. Allows you the start the motor retarded and idle off shore out of the 5mph zone and then push to full advance. The bungie cord will keep it in full advance position.
kk

I agree this is a very good inexpensive way to assure the advance stays where it needs to be. Also the top plug looks to be lean. A carb adjustment may be in order.

I for one will not be offering any more advice on how to go faster until you get some decent safety equipment, namely a decent life jacket and helmet, and hooked up kill switch. You are risking life as as vegetable, or worse, running this boat without the proper equipment.

[BillCNC]

Bill,

I fully understand your concern, and I thank you for it.

I have ALWAYS had a functioning kill switch that is always being used, the motor will not start without it. I am also on the hunt for a lifeline life jacket and I own a full face motorcycle helmet, just was not sure if helmets for motorcycles and boats are one in the same. If you know of anyone with a life jacket in my size that's not to expensive, I'd like to hear about it. I wear a size XXL t-shirt and my pants size is 36x32 . I'm 5'9" tall and 225 lbs.

I'm not looking to go faster in this boat, I'm just looking for an education and to make the boat more efficient. Very rarely am I taking this boat over 45 mph and most of the time has been spent under that. Basically I have been learning to turn the boat because going straight, is just that, ... going straight. Again, ... speed in really not the issue, understanding how it ALL works together is were my interest is concentrated at this time. As a professional "Model Maker / Prototype Builder", ... it's always about the puzzle and how to solve it. My puzzle right now is efficiency of the aerodynamics/hydrodynamics along with the motor and it's effects and how they interact with one another. From those three working in concert with one another, , ... Yes, speed is the end result, but not my main concern at this time, ... I know how to control the speed via the throttle.

Again, I am learning, ... but I am far from ignorant to the hazards that come with speed as I used to race Speedway motorcycles on dirt tracks the size of a football field going 60-80 mph on motorcycles with one gear and no brakes. In fact to slow down for the corners, ... you have to give it more gas to break traction and slide the rear tire around, slowing you down.

Again, I'd like to thank you for all the information and advice you have given me so far, ... it is greatly appreciated.

Regards
Bill

[BillCNC]

A bungie cord wrapped around the handle and secured to the gas tank bracket works real well for lake use. Allows you the start the motor retarded and idle off shore out of the 5mph zone and then push to full advance. The bungie cord will keep it in full advance position.
kk

The mag is not moving during operation, ... I checked several times during the day. In fact, ... one pull starts with the boat in the water are being made with the handle all the way over to the right, ... exhaust side.

[BillCNC]

Not sure how one would adjust a carb to make one cylinder run richer on a multi-cylinder engine that has one carb.

Maybe it has something to do with the reeds?