Freestyle New Thread - My Superfreak with TL is not running good! Help!

[Wiseguy92]

I just installed a new digital brain on my Rok. Good spark with the plugs on the motor as you have but wouldn't start, just cough. I did have to switch plug wires front to back for some reason with the new brain, something Msd has changed internally in their build I'm sure but whatever, prob solved n it rips once again.
You need to shoot your timing with a lite period. All the dip switch settings work with each other to get the desired curve based off that starting point. You have to know where your starting from to get it rite. That said, my static timing is higher than 31 degrees and the motor actually stalls the starter most every time I start it due to the high advance. But it still starts good and runs as it should. Too much static timing won't cause your symptoms IMO. Spec on the gap between the triggers and magnet on the wheel is .050-.090" also. I have set them up at the .050" n had problems. .075-.090 is the sweet spot I have found. Good luck, elect probs are a pain!


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[BrightE's]

I just installed a new digital brain on my Rok. Good spark with the plugs on the motor as you have but wouldn't start, just cough. I did have to switch plug wires front to back for some reason with the new brain, something Msd has changed internally in their build I'm sure but whatever, prob solved n it rips once again.
You need to shoot your timing with a lite period. All the dip switch settings work with each other to get the desired curve based off that starting point. You have to know where your starting from to get it rite. That said, my static timing is higher than 31 degrees and the motor actually stalls the starter most every time I start it due to the high advance. But it still starts good and runs as it should. Too much static timing won't cause your symptoms IMO. Spec on the gap between the triggers and magnet on the wheel is .050-.090" also. I have set them up at the .050" n had problems. .075-.090 is the sweet spot I have found. Good luck, elect probs are a pain!

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The wires are in decent shape, there was some hodge podgery but nothing I couldn't clean up with some wire organization. So you're saying even with good spark you were having trouble getting a solid start and run? When you say you had to switch wires from front to back, are you saying the channels to the coils were wired opposite from what they should have been direct from the factory? Or that you just had to actually use different plug wires from the ones you had?

I'm going to check the gap again this weekend as well - thanks for the pointer. About the static setting, I am 95% sure I set it really well at 31 degrees, and like you said, it should not really be causing a starting issue, especially considering I have the 'Start Retard' setting on so it's dropping 20 degrees at start for the first 1000RPM.

 

[Wiseguy92]

You should not need to change Chanel wires, brown, yellow, orange for your prob. You have good spark on both plugs so in my mind you don't have a bad Chanel. Gap is prob in range again good spark visually but that may change inside the head under compression. Just need to check gap.
My ski would not start as the spark was being sent to the bdc cyl to fire not the tdc cyl. That was easily fixed just by swapping plug wires cyl to cyl in my case on the motor.
You said yours ski did run but acted up out in the lake n now from what I read it will only cough in 30 tries rite? It will only cough if spark is sent to the bdc cyl is my point. Leave everything as it is and simply swap plug boots from cyl to cyl n that will eliminate that or it will work. If your ski actually runs now the way it is that is not the prob. Hard to blame carbs as it ran good before the TL.....but the low dose seem lean and the high seems big for a 710. My 927 wdk motor with 46 specs is upside down n has 125 highs n 135 lows...with TL


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[BrightE's]

So here's and update. I pulled the TL system out, and then pulled the carbs out with the intention of putting new jets in and testing pop-off.

I tested the slave carb and it pops off around 50psi, fine. When I test the master carb, air is flowing out all around the gaskets when I pressurize it. I can't even get it up to 30 psi because the leak is so bad. I feel like it needs new seals and gaskets, which is funny cause I just replaced them last season, though I did use SBT.

This has got me seriously wondering if this is a carb issue, not a TL issue.

If I hit up my local Yamaha waverunner dealer/repair shop, they should have Mikuni carb rebuild kits for sale right?

 

[shepster]

Most ski shops should stock mikuni kits and I will pretty much guarantee that's your problem

 

[BrightE's]

So here is where I am at. I am wildly frustrated at this point.

I spend all day chasing down genuine Mikuni carb rebuild kits because while pop-off testing I was getting serious leaks in my carb gaskets. I bought an SBT kit thinking it would help... and never again. SBT will not be receiving my business again for their Mikuni kits.

Anyhow, I put two new genunie Mikuni carb rebuilds in, they're prefect. I have pop-off at ~40psi on both carbs, I have fuel, I have air, I have spark. 75 Low Pilots are in. I changed my max advance to 26 to play it safe as I found I only have about 165psi on both holes. I can't get it to fire, it just wont do it. I switched the spark plug wires from hole to hole and it will backfire once or twice when I do this, but when I have them set normally, it just wont even bite. I don't know what to do.

I checked my air gap and I'm at 0.050" which is within spec. Help!!

 

[Wiseguy92]

I set a TL up years ago at .050" as it was the tight end of the spec thinking it would be better than a larger gap. I was wrong. I can't recall the exact result but made notes to never do it again. I called Msd n their Tec guy told me to open it up. Once I opened it up to .080" away I went.
Don't want to write a book here but this is good info I learned regarding ignition timing and this will work for any two stroke engine.
Install a degree wheel on the mag side of the crank thru the bolt. Get the mag piston to tdc n set up a pointer to 0 on the wheel. Install a 2" travel indicator into the mag cyl spark plug hole n set it to 0. Rotate crank backwards(advance of tdc) to 10 degrees, record the amount of indicator travel on a cheat sheet on line 1, 10 degrees. Now go to 11, record, 12 record, do every # up to 35 degrees. Now you have a timing cheet sheet for your stroke motor with your rod legnth.
Remove degree wheel n pointer n you will never need to do that step again.
Now go to your pto coupler. I set up a pointer off my rear bed plate mounting bolt. Make it rigid enuff it won't bounce all over when you start the engine. Mine is out of a piece of 1/8"x1" flat alum stock. I just trimmed the pointing end Into a point. It just has 1 30degreeish bend in it so it points at the coupler.
Now with your indicator installed in the mag cyl roll the crank to 20 degrees from your sheet. Make a mark on the coupler n label 20. Thin sharpie works good. Now 25, 30.
Remove your indicator n install plugs an your timing lite. Roll the engine n shoot the lite to see where you are. If you don't see any of your numbers with the lite your out in left field and a major move is nessary on your stator plate. In your case where it won't start just leave the plugs out on the motor so you will get more Rpms out Of the starter. Once motor runs, put plugs in and do the same and shoot it with it running to dial it in.

You must not be firing within 30 degrees of tdc. It's the only thing that makes sense. If it coughs in both cases with switching plugs your firing the plug with the exhaust port still open. Call me if you have any questions, 989 529 6852. Mike


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[Philip Clemmons]

Jetmaniac stocks the mikuni kits. Also, what plugs are you running? They look like HS plugs, not the typical ES. The ES plugs are much longer. Most ADA heads I've seen use a BR8ES plug, but there boils be exceptions.

 

[BrightE's]

I FINALLY narrowed down the problem with Nate_D's help. It's a bad coil that would spark occationally, but was not getting the plug what it needed when it needed it. I ran the front cylinder channel through the back cylinder coil, to the front cylinder, and left the back hole open. Sure as sh*t it fired right up on the front cylinder for the first time. I've got a new coil already on it's way to make it to me by the weekend from JM, and some longer ES plugs.

I'm pumped beyond belief to tear it up on the water finally.

 

[BrightE's]

Also thanks for all your guy's help, man. I was losing my mind over the thought that I wasn't going to ride till late summer.

I'm glad I didn't have to bring it into a shop, it's a good feeling to not have to do that.

 

[BrightE's]

So here's a new development. I got a new coil, thanks Jetmaniac. It fires great, but now the other coil is acting up! I rode once, and only once with both cylinders firing and it was AMAZING. I tried to lock it down like that in a more permanent setup after tinkering, and now the other coil is failing me.

The coils seem to not like to be grounded through each other, but rather independently grounded to the engine. Is that a normal thing? Also, I'm bolting the brain, coils, and solenoid all to an aluminum plate, are they all independently isolated as to not interfere with each other while bolted on a conductive plate?

 

[Wiseguy92]

Ground is ground is ground. Dosent matter if they are independently landed to the plate or ganged up on the same spot. Should not react to different grounding spots..... Normally the more you connect each point it gets better not worse...


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[speedysprocket]

It does matter which one of the two bolt holes on the coils is grounded, the other one doesn't matter. One hole kind of looks steel, and the other brass. Check the instructions again, but I think it's the steel looking one.
And no reason to isolate them on your plate. The only recommendation is to keep the coils further than 6" from the brain, but many people break that suggestion without issue. And if you do bolt your coils directly to the plate , it doesn't matter which hole you ground, because they will both be grounded.

 

[BrightE's]

It must just be a bad coil then, two of them.

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[Sanoman]

Paul l hate you are having all this trouble with the new ski.Hope you get all of it worked out!

 

[just joe]

On 2 occasions I've had both coils bad. Then a brain go bad and a replacement sent from MSD on warranty was DOA. I felt like ripping the whole ignition out and tossing it on the grille.

I know what this is like, keep with it.

 

[BrightE's]

So here is the WEIRDEST thing I have run into yet. The front cylinder is running fine, no matter what (I have the new coil on it). It will run off any of the three coils I have (1 new) off the back cylinders if one of the coils is removed from the aluminum plate I have everything bolted to, but as soon as I bolt the second coil to the plate (back cylinder), the one coil stops working. But it will still spark just fine like nothing is wrong. It's crazy frustrating. I can ground a coil to the plate from a wire, and just plug the coil into the brain, and it will fire on perfectly on the back cylinder. It's almost as if it is a frequency interference or something, or something totally weird that is shorting through the aluminum plate everything is on. I feel like my next logical step is to replace the aluminum plate with a Delrin or ABS plate and see if it fixes it. Both coils are about 5.5" from the brain.

 

[just joe]

Do you have the newer coils in a plastic/resin casing, or the older metal ones?

I always used a fiberglass ate to mount to, and grounds from each coil to motor. But I've seen many use CF or aluminum.

 

[BrightE's]

One new plastic housing, Twp older metal ones. The metals are the ones that don't work when mounted

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[just joe]

If it were me, id get one more coil, a new plastic one. Second choice would be a non-conductive mounting plate.

I eventually mounted my coils on a separate plate than the brain. Many conversations with Ray at MSD before doing so. It worked for me, even though it seemed others didn't have to.