Hard starting Yamato 102

[johnsonm50]

Make sure the rope plate is not warped & wobbling up & down.

[ZUL8TR]

insert looseness

Wouldn't the loose threads affect the heat transfer making it a bad scenario?



Thanks Jack, ... It doesn't need to be donated, ... I would gladly pay for it. No free rides here.

The loose threads will have some effect on the heat transfer but might be minimal. So run them and then inspect plug and piston crown and look for signs of overheatingn etc. Here is some reading:

http://www.strappe.com/plugs.html

http://www.boatracingfacts.com/forum...ead.php?t=5472

[BillCNC]

Well I fixed the kill switch wires and made a spark plug dial indicator, set the points to .012" and have a tester for the points hooked up and am ready to set the timing to .225"BTDC.

My question is;

Do I set the timing with the magneto handle centered or all the way to right (exhaust side)?

[bill van steenwyk]

Magneto handle position

Since you are now to the point where you are setting the TOTAL ignition advance on the motor, you would want to set it (with the dial indicator as previously discussed) so that max advance comes where you position the handle for WFO lake running.

If that is all the way to the right on the exhaust side, then that is where you want the handle. If you set it at any other handle location, then if you move the handle further to the right, you run the risk of running the motor with too much spark advance and burning/sticking a piston. Probably the advance stops were set at a location when you got the motor. That is where I would try to set max advance, because that is where the factory set it when the motor was new.

This will also allow the spark advance to not be fully advanced to the max timing you are going to be setting it at when the lever is moved to the left for easier starting, and will eliminate "kick back" when pulling the rope over as the spark advance will then be somewhat retarded. After starting you can then move the lever to full advance when ready to run full throttle.

I am sure Montoya has these instructions on his web site, or they are in the manual probably if you got one with the motor.

Good Luck

[BillCNC]

Hi Bill,

Yes, Montoya has the information on his site, but I was just unsure as to where the position of the timing handle should be during the process. I am going by the manuals starting procedures which call starting the motor with the timing handle centered and then moved to the far right once started. I was unsure at what position the handle should be in for the timing process. I was confident that it would be all the way to the right, but I was just making sure of that before I did any damage to the motor. It's far easier to ask, than rebuild.

I have everything gaped and timed, point gap is .012" and the timing is .228". Plugs are gaped at .025" and I'm going to start it up as soon as the neighbors who are late sleepers wake up.

[BillCNC]

I ordered a fuel pump setup from BTM, a few gaskets from Montoya and am currently in the process of buying a 14 mm head and various other gaskets for spares and maintenance.

This should solve all my current issues.

[tim king]

What Bill said about the timing is abesolutely right. If you keep messing with your plugs you WILL burn a hole in your pistin. Just retard the timing and you could troll with this engine. Its a no brainer for me.
ps those kill switch wire's can't be helping.

[BillCNC]

Tim,

The only messing with the plugs I have done, was to swap out the NGK BR10EXI plugs to NGK B10EGV and gap them, that's it. Like I said, I'm in the process of also swapping out the head from an 18 mm with inserts to a 14 mm head making it so I dont need inserts.

I have made the max spark advance all the way to the right and that's the position I timed the motor to. I never touched the position of the magneto setting as the motor ran there just fine were it is. My only issue was starting it in the water. On land, ... no problems, first pull, ... but in the water, ... forgetaboutit, it was more trouble than it was worth!

The rope length I made for starting from in the boat was 34" over all length including the handle. This put my body to far aft making the back pressure in the exhaust worse. I have since changed the length to 48" for self starting placing my but on the dash above the steering wheel. This should put the motor higher out of the water relieving some of the back pressure in the exhaust making the engine easier to self start in the water.

Also, the kill switch issue has been solved, .. I used a pair of thinner wires and attached them with 3M's Marine Adhesive Sealant #4200. To be sure they stayed flat against the coil plate assembly, I folded up a bunch of wax paper and laid it on top of the sealant and bolted the starting pulley down forcing the wax paper to force the wires to lay perfectly flat. Once the sealant cured for 2.5 hours, ... I unbolted the starting pulley, removed the wax paper and laid little balls of modeling clay on the wires and re-bolted the starting pulley back down. I then unbolted the starting pulley and pulled the clay out and measured the clearance between the starting pulley and the coil plate assembly and there is a .065" clearance, ... so there is plenty of room now.

All,

For those that self start their 102's, ... what rope length are you using?

Thanks to ALL for your help
Bill

[bill van steenwyk]

Two things....

If you mentioned how deep (i.e. center line of propshaft to bottom of boat) your motor was, I missed it. Should be for this motor about 3/4 to 1/2" below bottom of boat. If deeper than that, then this could be a problem causing your boat to sink and take on water when you are in the back, and also water level in tower housing/megaphone and prop/water load. It is difficult to tell from your avatar picture.

Also I believe you mentioned you tested/boated alone, and did not have help when you went to the lake.

I have several friends who have suffered serious injury that now affects them every day of their life, and also impacts their families, from accidents that occurred causing them to be thrown from a boat, and even though they had life jackets on, their head was below the surface of the water for a sufficient time they suffered brain injury in addition to other trauma.

No matter the speed, it is NOT a good idea to test or run a boat of this type by yourself with no other boats around. You can get on your head very easily by hitting a pleasure boat wake and if you are not seen to be in trouble, you can be an invalid or worse the rest of your life. It can happen to you. These are fun boats and motors, but can hurt you in a second if the proper precautions are not taken. Not trying to be an "old fart" but it can happen to you, if proper precautions are not taken and you test the boat alone and no help, especially if their are pleasure boats in the area making the water rough.

Have fun and be careful.

[BillCNC]

I fired up the motor and boy, ... what a difference just on the stand. I hook up the water and it started in 4 pulls. I ran it for about 45 seconds and shut it down. I let it sit for a minute and it started on the first pull. I knew it probably wood so I shut it down right away. Then I started it again, but this time, ... I only had the rope wrapped 1/2 a turn. Fired right up! The motor was A LOT more crisp sounding and revved up quicker.

I also cleaned the outside of the carb very well and shot a little down the intake while it was running. I know that I dont have it in the water and it will act different, but I can already tell, she's running better just by comparing them when they ran on the stand.

Next week I should have the fuel pump setup on it making it so I dont need to refuel every time I blink.

[BillCNC]

If you mentioned how deep (i.e. center line of propshaft to bottom of boat) your motor was, I missed it. Should be for this motor about 3/4 to 1/2" below bottom of boat. If deeper than that, then this could be a problem causing your boat to sink and take on water when you are in the back, and also water level in tower housing/megaphone and prop/water load. It is difficult to tell from your avatar picture.

Hi Bill,

The center of the prop shaft is 3/4" below the hull.

Also I believe you mentioned you tested/boated alone, and did not have help when you went to the lake.

I have several friends who have suffered serious injury that now affects them every day of their life, and also impacts their families, from accidents that occurred causing them to be thrown from a boat, and even though they had life jackets on, their head was below the surface of the water for a sufficient time they suffered brain injury in addition to other trauma.

No matter the speed, it is NOT a good idea to test or run a boat of this type by yourself with no other boats around. You can get on your head very easily by hitting a pleasure boat wake and if you are not seen to be in trouble, you can be an invalid or worse the rest of your life. It can happen to you. These are fun boats and motors, but can hurt you in a second if the proper precautions are not taken. Not trying to be an "old fart" but it can happen to you, if proper precautions are not taken and you test the boat alone and no help, especially if their are pleasure boats in the area making the water rough.

Have fun and be careful.

I had my son with me and we rented a chase boat for a couple of hours. I took all the precautions. I also made sure I was on the lake when they opened at 7am. The water was flat and traffic was a hand full of boats going to a fishing location and dropping anchor.

I fully understand your concern, although I see this as is my play thing, ... yet, I understand it's not a toy. It will only be used as one of the first boats on the lake and on very calm days and I dont even want to take it out if the wind is blowing more the 6-7 mph. I also don't have any intention of putting a death grip on the throttle anytime soon.

[mercguy]

Tim,

The only messing with the plugs I have done, was to swap out the NGK BR10EXI plugs to NGK B10EGV and gap them, that's it. Like I said, I'm in the process of also swapping out the head from an 18 mm with inserts to a 14 mm head making it so I dont need inserts.

I have made the max spark advance all the way to the right and that's the position I timed the motor to. I never touched the position of the magneto setting as the motor ran there just fine were it is. My only issue was starting it in the water. On land, ... no problems, first pull, ... but in the water, ... forgetaboutit, it was more trouble than it was worth!

The rope length I made for starting from in the boat was 34" over all length including the handle. This put my body to far aft making the back pressure in the exhaust worse. I have since changed the length to 48" for self starting placing my but on the dash above the steering wheel. This should put the motor higher out of the water relieving some of the back pressure in the exhaust making the engine easier to self start in the water.

Also, the kill switch issue has been solved, .. I used a pair of thinner wires and attached them with 3M's Marine Adhesive Sealant #4200. To be sure they stayed flat against the coil plate assembly, I folded up a bunch of wax paper and laid it on top of the sealant and bolted the starting pulley down forcing the wax paper to force the wires to lay perfectly flat. Once the sealant cured for 2.5 hours, ... I unbolted the starting pulley, removed the wax paper and laid little balls of modeling clay on the wires and re-bolted the starting pulley back down. I then unbolted the starting pulley and pulled the clay out and measured the clearance between the starting pulley and the coil plate assembly and there is a .065" clearance, ... so there is plenty of room now.

All,

For those that self start their 102's, ... what rope length are you using?

Thanks to ALL for your help
Bill

"I have made the max spark advance all the way to the right and that's the position I timed the motor to. I never touched the position of the magneto setting as the motor ran there just fine were it is"

.....you have to move the mag to set the timing......

[bill van steenwyk]

It is difficult to tell from the picture you posted..........

.........but from the angle of the photo the motor looks to be slightly "tucked under". By that I mean if you took a straight edge and put it parallel to the prop shaft the other end of the SE would not be parallel with the boat bottom, but be closer to the bottom at the far end than at the transom.

As you are probably aware, this adjustment is critical for the boat to ride properly and not run with the bow in the water. Your Hydro should run (when you get it correctly set up) with the trailing edge of the sponsons about a couple of inches off the water.

You want to be careful and make this adjustment in small increments so as not to take a chance on blowing the boat over backwards, although your boat seems to be large enough the chances of that happening without a real screw up in the "kickout" of the motor would seem to not be great. If it were me and I was starting from scratch, I would set it "dead level" or straight/parallel with the bottom. (prop shaft)

When you get your starting problems ironed out you might want to have your son use a video camera to take some video of the boat running WFO past him in good water. You can tell from the video if the boat is getting too high in front and the sponsons are too far off the water. Some boats will also reach a certain speed where all of a sudden the boat feels really free, like you are "floating on a cloud", and the nose of the boat will kind of "pop up" several inches. This can also be accompanied by a "rocking" from side to side like one sponson is lifting off the water and then the other. That is actually what is happening and is called "spilling air" and the boat is trying to relieve itself of the extra air it is packing under it by rocking from side to side because the angle of attack of the lower unit is two far out from the straight line of the bottom. At that point you want to back off the throttle and slightly tuck the motor back the other way, as you are getting on the edge and could get wet.

Re Mercguys post:

Darren is a really sharp mechanic and has helped me several times with my 150EFI when I retired from racing several years ago and got a bass boat. I think what he was trying to get across is you need to be sure the handle will not move any further to the right towards the exhaust with the timing set at the .228 you set it at. You do not want the timing to be able to advance any further than that by NOT having the handle against the stop, as you could burn/stick a piston if it were able to move further advanced after setting it where you state you have it. In other words, you should have had the handle all the way to the right before setting the timing at max advance. If he has picked up something else that I did not from your posts, I am sure he will chime in.

[ZUL8TR]

timing

In short, with points set at say 0.012" (102 manual range is 0.012" to 0.016") for say top cylinder, rotate crank so dial indicator reads 0.228" (or what ever you want to set at) from top dead center of that piston. Then adjust the mag stop so the ignition point to that cylindere just breaks open as indicated with the buzz box just going off, then lock the mag stop. Then without moving the mag stop set the dial indicator to read 0.228" for the bottom cylindere and set those points to just open (they will not be same setting as the top but should not be less than 0.012"). If adjusted correctly the plugs will now fire at 180 degrees apart and at 0.228" before top dead center.

In each case adjust the dial indicator to read zero at top dead center before doing any adjustments for each cylinder.

Doesn't matter if you start with the top or bottom cylinder.

[ZUL8TR]

ride angle

[QUOTE=bill van steenwyk;212861].........but from the angle of the photo the motor looks to be slightly "tucked under". By that I mean if you took a straight edge and put it parallel to the prop shaft the other end of the SE would not be parallel with the boat bottom, but be closer to the bottom at the far end than at the transom.

As you are probably aware, this adjustment is critical for the boat to ride properly and not run with the bow in the water. Your Hydro should run (when you get it correctly set up) with the trailing edge of the sponsons about a couple of inches off the water.

You want to be careful and make this adjustment in small increments so as not to take a chance on blowing the boat over backwards, although your boat seems to be large enough the chances of that happening without a real screw up in the "kickout" of the motor would seem to not be great. If it were me and I was starting from scratch, I would set it "dead level" or straight/parallel with the bottom. (prop shaft)

When you get your starting problems ironed out you might want to have your son use a video camera to take some video of the boat running WFO past him in good water. You can tell from the video if the boat is getting too high in front and the sponsons are too far off the water.

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Bill looking at the video he posted on the 1st page the boat drags the sponsons at full speed. So boat riding to low.