Help! T8 won't start now

[Starfish]

Panic! Not the time for kicker trouble right when I need it for springer season!
I have a 2003 T8 that has a lot of hours but has been flawless other than a failed tilt system that I replaced. It ran like a top all day yesterday until I announced the last pass after a troll from I5 to the RR bridge. I got back up to the top and discovered that the kicker was still in the down position. It was in neutral and shut off, but I must have forgotten to tilt it up. No big deal, I went to start it as normal and... no starty. It cranked over just fine but didn't fire. I did all the usual checks, made sure it's in neutral, checked fuel, took off the kill switch lanyard and put it back on making sure the switch is pulled all the way out, etc.

Today I don't have time for a full diagnostic but made the time to check the plugs (look okay but smell slightly of gas), check the oil (slightly high on volume but no gas smell or water in oil), checked that the fuel bulb and hose is working, filled up a cooler full of water and tried starting the kicker. Again it just cranks, sounds almost like it's going to catch and thows an occasional sputter but no dice. Water comes out pee hole if I crank it long enough.

The question is, could I have damaged anything by running to the top of the drift with the kicker down? I've done it before with no problems. Tomorrow when I get back home I'll try replacing plugs, changing the oil, checking compression, replacing the fuel line, and saying a prayer. Any other things to check before I jump off a bridge?

[Thunder jet]

Try sending a pm to "smalldog" here on I-fish. He is a Yamaha mechanic and may be able to point you in the right direction. Sorry I cant be of more help. Good luck

[RiverMan]

You are pretty clever on this stuff Starfish and I'm surprised you haven't figured it out. Hopefully someone here will jump in and help you out.



RM

[lightning]

Water thrown up may have gotten into the electrics. I know you don't go real slow. Try washing down plug wires at the coils, ignition wires etc with contact cleaner maybe. Then use dielectric grease to prevent it next time.

Be careful around bridges.

[Lead Bouncer]

Last year, I wasnt paying much attention to the lid when I pushed it down and locked it.

I pulled off a plug wire.

[Starfish]

OK, an update so far. I changed oil, plugs, and fuel line. Used a spark tester and verified strong spark on both plugs, verified strong clean fuel flow up to the carb, drained the carb bowl and saw no evidence of water or debris. Checked compression and had 135 on both cylinders. It's popping occasionally (both exhaust and backfire) while cranking but it still won't start. I even gave it a shot of ether and didn't get it to start. I just pulled the carb to tear it down next. A first glance after removing the bowl looks spotless, I have a hard time believing there's going to be a clog here with it looking like brand new (despite a few thousand hours). Any ideas? I'm wondering if somehow I totally slipped timing position since it appears I've got air, spark, and fuel.

[Jrr]

You have the right idea sounds like you checked everything, fuel, air,compression and spark delivered at the right time it should run, timing is the next step.I have seen some older motors pop or backfire and jump timing.

[StickFish]

Originally Posted by Starfish

OK, an update so far. I changed oil, plugs, and fuel line. Used a spark tester and verified strong spark on both plugs, verified strong clean fuel flow up to the carb, drained the carb bowl and saw no evidence of water or debris. Checked compression and had 135 on both cylinders. It's popping occasionally (both exhaust and backfire) while cranking but it still won't start. I even gave it a shot of ether and didn't get it to start. I just pulled the carb to tear it down next. A first glance after removing the bowl looks spotless, I have a hard time believing there's going to be a clog here with it looking like brand new (despite a few thousand hours). Any ideas? I'm wondering if somehow I totally slipped timing position since it appears I've got air, spark, and fuel.

Sounds like you valves are WAY out of time if it will pop and backfire. The belt on my T8 loose and I could see it being pretty easy to slip the belt of the motor was in gear. PM Smalldog or take it to Inflatable Boat Center in Portland they will get you fixed up

[GSD]

Wouldn't be the first time that a Lanyard/Safety Shutoff Switch failed in the normal run position. If you haven't already, try unhooking one of the leads to the switch and see if it will start. The switch is a "normally open" switch but sometimes they do fail or get dirty and not operate properly.

[Vinny]

That popping could also be the ignition way out of timing. Don't know how that would have happened all of a sudden.

From what I've heard so far, I'm with Stickfish on valve timing or perhaps ignition timing.

I'm not totally following GSD. If the Safety Shut-off is normally open and you disconnect a wire, then the circuit is still open. Unless, the switch is supposed "ground out" the ignition primary when the lanyard is pulled, then GSD's suggestion makes perfect sense. However, a strong spark reduces the likelyhood of a kill switch issue.

[GSD]

Disconnecting one wire would "open" the circuit if the safety switch was faulty and stuck in the "closed" position.



The neutral safety switch would be the next one to check to verify it is operating properly.

[Starfish]

Thanks for the ideas guys- I'll definitely try them out. I had thought I ruled out the kill switch by checking spark but will doublecheck. Otherwise I'm really leaning toward the timing issue.

[Starfish]

Didn't get too much time to tinker tonight unfortunately. I reassembled and reinstalled the carb, tried starting it (no change), unplugged the kill switch and tried it again (still no luck). I looked for timing marks... found the one on the drive gear (pulley) but couldn't spot the one under the flywheel. Do I need to pull the flywheel to see it?

[smalldog]

After you cleaned the carb...did you check all the passages to make sure they were free of debre before you put it back together?? I have a sonic cleaner and I often have to run carbs two or thee times through it to get everything out.
You may have to pull the flywheel to check the marks if you cant see it.
Remember...the key does not hold the flywheel on. It is there only for alignment. The compression of the flywheel onto the tapered end of the crank holds it. Is the nut loose at all?
I am in Georgia right now at the Yamaha corp headquarters.
How far are you from Portland?
The bolts are 10mm that you use with your puller....screw them in by hand.. if you go too far in you will hit your coils and ruin them. If there is a cap to cover the pointed end on your puller..use it. Better than taking a chance on splitting the end of the crankshaft. Use a half inch airgun to take off the flywheel nut. Hold the flywheel so it doesnt turn the crank backwards with a spreader bar (you dont want to turn the driveshaft backwards or you will mess up your water pump impellar.)

Seems odd that it was running just fine and all you did was shut it off and run up again.
Even if the motor was left down... not much should happen.

Does it turn over easy with the pull starter?

The double wire ignition coil fires both plugs at the same time all the time. It is a waste spark ignition system.

Ignition timing is not adjustable... valve timing is controlled by the timing belt, rocker arms and valve lash.

If you havent fixed it by the time I get back next weekend... p.m. me.

Dan

[lightning]

Northwest Marine has 7 on the shelf. A new one would look good on the Weldcraft 206 DV Maverick they have. Maybe mounted next to a Yamaha 200F?

[Starfish]

Thanks Dan - I sent you a PM before seeing your reply here. Thanks for taking the time to post from the road. Unfortunately I'm four hours from Portland.

The engine turns over easily; perhaps even too easily, though it does have compression. I think my next check is going to be to pull the valve cover as you suggested in a PM; do I need to drain the crankcase oil before doing so?

[smalldog]

I really need to see this motor.

Too easily? As compared to normally?

Also, clear your messages...it wont accept my pm's...says your full up.

Dan

[Starfish]

Sorry about that, cleared some PMs and made more room.

Too easily as in I can turn the flywheel quite easily by hand pressure, though I can feel the resistance of the compression stroke- just that some engines seem to have more resistance. It doesn't seem any different than normal when using the electric start.

[UncleRichie]

Have you replaced the plugs? If the engine was turning over when you ran back up u could have fouled the plugs would be worth a shot . My honda 8 hp is a great one for fouled plugs ,I have tryed to clean them only works part of the time.
Richard

[Starfish]

Originally Posted by UncleRichie

Have you replaced the plugs? If the engine was turning over when you ran back up u could have fouled the plugs would be worth a shot . My honda 8 hp is a great one for fouled plugs ,I have tryed to clean them only works part of the time.
Richard

Thanks, yes- I replaced the plugs, changed the oil, replaced the fuel line, checked the compression, bypassed the kill switch, and also tried bypassing the CDI controller. It's looking like either timing or valves, I'll have to dig deeper this week.

Luckily a good friend loaned me a kicker so now I'm temporarily:
"Team Tri-Motor"

[UncleRichie]

Ok one last shot,
when u ran back up would there be enough preasure on the prop to shear the key in the flywheel ? sounds like you have checked everthing else out. Grasping at straws here
Richard

[Starfish]

Originally Posted by UncleRichie

Ok one last shot,
when u ran back up would there be enough preasure on the prop to shear the key in the flywheel ? sounds like you have checked everthing else out. Grasping at straws here
Richard

Yeah, I was wondering that too... next steps are to pull the valve cover and look for something broken, and pull the flywheel to check the woodruff key. Pretty weird!

[garyk]

STARFISH.....don't leave the readers hanging!!!!

What's the update??????????

[Starfish]

Originally Posted by garyk

STARFISH.....don't leave the readers hanging!!!!

What's the update??????????

Sorry! I still haven't gotten time to tear into the valves or the flywheel, believe it or not... Dang work and volunteer stuff keeps getting in the way, it's killing me! Luckily I have a boat ride for Thursday already and hope to tear the kicker apart that afternoon if I don't go back to work that day.

[smalldog]

Pull the flywheel first and check the timing marks.

[Starfish]

I got the nut off the flywheel but don't have a puller yet- I was hoping I could tap it loose and get the flywheel off but it looks like I've got to hit the parts store tomorrow and get a puller.

[Smj]

You should check to confirm that timing between the crank shaft and cam shaft are where they should be. One or two teeth jumped on the timing belt would cause the conditions you have described.

You may be able to see if the key aligning the crank to the flywheel has sheered once you have the nut and washer off the top of the crank. The slot in the crank shaft will line up perfectly with the slot in the flywheel. I would say it's unlikely you sheered the key, with out hitting something solid while the motor was running though.

Smj

[Starfish]

Yeahaw! Sure enough, pulled the flywheel and found a sheared woodruff key and the crank spun about 15 degrees off.
She's running now! Time to go fishing.

Thanks all, especially smalldog, for the sage advice.

[fishkisser]

Whooo hooo !!!
I love it when its something simple ...

[GSD]

Originally Posted by Starfish

Yeahaw! Sure enough, pulled the flywheel and found a sheared woodruff key and the crank spun about 15 degrees off.
She's running now! Time to go fishing.

Thanks all, especially smalldog, for the sage advice.

Simply amazing! Thanks for updating and congrats on the fix.

[smalldog]

Good luck and catch some fish.