Timing and synchronizing a 1988 v4 130 hp 2 stroke. Need help.

Joined
Mar 30, 2018
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OK, so I am going to give a brief history, hoping someone can help me out. I bought this boat from a buddy. We had a deal while it was running fine, then one day while still in his ownership it wouldn't shut off. Long story short he bought a "new" used harness. Still couldn't get it going so he took off a rebuilt the carbs. Still couldn't get it going. This is where I come in.

I ended up tracing the problem to a bad rectifier, which in turn took out the cdi, or vice versa. It now will run on all four cylinders, and shut off fine. However, before I got it, timing, throttle, control, etc, etc, were removed, and the engine spun over and turned, so I bought the factory service manual, and just started checking things off, because between the net and free stuff out there I was getting conflicting numbers. Now, when I say checking things off I literally mean front to back. I am machinist/millwright by trade, done all my own vehicle and boat maintenance for the past 23 years, I am very ocd when it comes to this stuff, so I am hoping perhaps, I am just not reading something right.

Manuals say, put dial Guage in cylinder 1, set TDC at 0, then turn clockwise until dial Guage goes down 0.12" set timing mark on 22 degrees btdc. Got that. Now it says to set the control linkage lengths, bang on. Attach them. Fully retarded Timing mark at 5 degrees atdc, the mark on the magneto control Iines up with the mark on the underside of the flywheel. Fully advanced mark is at 22 degrees, and the mark on the magneto control lever lines up with the mark on the underside of the flywheel. Long story short statically, I set everything according to the manual, and I was going to dial it in with the timing light.

I try and start it, nothing. Won't fire, just killing the battery. I even bought a new battery. Now out of desperation, I tried starting it with the fast idle, (advances timing) it started instantly, and ran better than it ever has during this saga. I throw the timing light on it, it's way out according to the timing light. Like 15 degrees btdc. Ok fast idle is on. I let the engine warm up at a point where it would run at the lowest possible idle without dying. Once it was warm, I tried making some live adjustments. When I tried to get the dynamic idle, and Fully retarded timing to match the manual, once I would retard past 10 degrees btdc (closer to 5 degrees atdc manuals numbers for idle) it would just die. Like die even if I tried reving it with the throttle. The further advanced at idle it runs, the better the engine runs.

Things I have replaced. All fuel lines, filters, fuel, bulb, fuel pump, all vacuum lines, rewired, and confirmed all boat wiring is good. New deep cycle starting battery. Rectifier, cdi unit, oil level switch, carbs rebuilt twice. Once by a dealer, and once by me because I don't trust said dealer. Starter, um, I am sure there is more. Some stuff was because I am ocd, and some stuff was trying to rule things out.

Anyway, I realize this is all over the place, but I am hoping someone can read through my frustration, and perhaps ran into this before and can give me an idea of where to go. I am going to reconfirm all the static markings line up still, and go from there.

Forgive my spelling and Grammer. Out at the boat and just trying to send this off quick.
 

99yam40

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Sep 7, 2008
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I did not read anything about using the choke while trying to start.
but raising the fast idle lever not only opens the throttle to allow more air in, it also may change the timing some also like you wrote.
Could there be too much fuel to air for the cylinders to fire?
do the plugs have spark when it will not start?


I did not read anything about adjusting the idle speed screw to crack open the throttle plates when at idle.
I do not know much about your 88 130, but most call for adjusting all throttle plates to fully closed and locking the linkage together at that point and then adjust to open a small amount
 
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Joined
Mar 30, 2018
Messages
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I did not read anything about using the choke while trying to start.
but raising the fast idle lever not only opens the throttle to allow more air in, it also may change the timing some also like you wrote.
Could there be too much fuel to air for the cylinders to fire?
do the plugs have spark when it will not start?


I did not read anything about adjusting the idle speed screw to crack open the throttle plates when at idle.
I do not know much about your 88 130, but most call for adjusting all throttle plates to fully closed and locking the linkage together at that point and then adjust to open a small amount
Thank you for your time. I adjusted everything step by step via the manual. In the manual I have, timing and synchronization is in chapter three. I did every step in that chapter, even on the oil pump etc. Again I am ocd. Yes, I tried starting with the choke, manual and electronic tried and adjusted via the manual. Idle speed screw adjusted, fuel air adjusted, again all via the manual. I do not have an inductive rpm guage however, to fine tune the carbs, but I mean the thing won't run even close to TDC, let alone 5 degrees atdc but will at 22 degrees before, and purr. I am so close to this I need to walk away. Haha. Am I an idiot and have the wrong timing light? I mean it's super super basic either on or off, no digital advance, or rpm guage built in. However even with the static timing done the thing should "run" this is not even close to that. I have confirmed strong, steady, blue spark on all four cylinders.

Is it possible to clock these flywheel, or are they keyed? Wondering if someone set it up not like the manual to be a little off. Have the needle point to TDC instead of 5 degrees after. That would explain the numbers on the flywheel and the timing light not matching the manuals numbers.
 

99yam40

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Sep 7, 2008
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8,231
are you sure the spark is not going away when you set to normal or close to normal timing?
just thinking wiring moved a certain way ends up killing spark maybe.

there is a key, I guess it could be sheared
But, TDC on pistions and marks on flywheel line up it should be good.
 
Joined
Mar 30, 2018
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OK update, I redid everything timing wise, and now I can get it to run, at about TDC. 1-2 degrees out, and it will just run. I am guaging the spark via the timing light, I think if I am going to get those last few degrees, and correct me if I am wrong, but the correct idle from here by adjusting the air-fuel mixture.

I noticed my flywheel has marks for TDC for each cylinder. With tdc1 having the scale. I put my timing light on each cylinder, and the marks almost line up on each cylinder. Manuals don't say it, but should the timing marks line up to TDC on all cylinders, because it has 5 degrees of advance? Or should the number 1 cylinder read 5 degrees atdc, with my basic timing light, and all others be at TDC?

Stupid questions, but honestly at this point I need to check everything. My plan was to get the timing as close as possible, then fine tune each cylinder via the timing light and the air-fuel screw to see if i can achieve a steady non-missing idle, and get those timing marks to line up. On two cylinders the spark was super strong and constant, bang on 2 degrees away from tdc, the two top cylinders were bouncing around a bit, which leveled out with some rpm, so i think at this point i can try fine tuning the carbs, to achieve the lowest possible idle. Sick of flooding my garage, and having to empty my tank. So hauling it to the water today, and just going to chill at the doc. I will report back.

Any special tips or tricks would be appreciated. I must admit, I am not a carb guy. I hate the things. Hahah. Give me efi any day. Manual says turn all the way in until seated. Then turn out 7/8 of a turn, then adjust in by a 16th of a turn each time while fine tuning.

I also see a lot of posts saying that yamaha manuals are never 100% complete or correct, hence why I ask. Through this ordeal I have bought three manuals, carb tuning is kind of straight forward but vague at the same time, in the manual.

Thank you again.
 
Joined
Mar 30, 2018
Messages
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Also other things I remembered that I have replaced, are the reed valves. Set up via the manual with feeler guages etc. Also four brand new coils.

Question. The original spark plug caps are the screw on type (black), I believe they are a resistor type plug boot, correct me if I am wrong. The new coils however came with these red/orange ones that are super basic. However they are new. They are just the crimp style. Wondeing if i should stick with the factory style. I am ocd and like to replace little things like that on stuff I buy so I know it's most likely not going to leave me stranded. Same thing as changing all the fluids when you buy a used car. Peace of mind.
 
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