Tohatsu 35 hp 4stroke ignition questions

"Please pardon if this is a re

"Please pardon if this is a repeat - I posted earlier, but it didn't show up.

I have a Tohatsu 3.5 4-stroke outboard. Yesterday it wouldn't quit. I pulled the lanyard and all it did was start missing, but wouldn't stop running. So I pulled the cowl and pulled the plug wire off w/ a pair of insulated pliers. That did it <g>.

I checked the kill switch and wiring - had about 1 ohm of resistance, cleaned the bullet connector and the ground screw and connections, and now have it down to about 0.01 ohm resistance in kill position.

Remounted the outboard and it wouldn't start. Not even a pop. Opened it up again and tested both the plug. When I see a spark it's pretty weak. I tried a new plug - same results.

My first question is what could have caused the engine to not quit when I pulled the lanyard off the kill switch? 1 ohm doesn't seem like enough resistance to me to prevent grounding out the ignition.

My second question is could I have possibly damaged the coil by pulling the plug wire off the plug? I've never heard of that happening before.

And my third question is what's a ballpark cost for a new coil?

Thanks for any help,

Mark Kaynor"

1) Bad switch or the conne

1) Bad switch or the connectors were not tight.
2)No
3)Depends on the model number of the engine.

"Thanks TG. So now I'm ba

"Thanks TG. So now I'm back to troubleshooting the spark. What would cause a weak or nonexistant spark on this motor? The motor ran fine before it wouldn't stop. All I did (as far as I know) was clean the kill switch connector and screw and terminals for the ground. I've also replaced the plug, but the spark is still nonexistant to weak. Obviously something has changed but I'm at a loss.

The flywheel spins, the magnets are strong, the coil secondary resistance to ground is about 7.5K ohms.

It's a 2006 Tohatsu MFS3.5A.

Thanks again for any thoughts and suggestions.

Mark Kaynor"

Anthing in the ignition system

Anthing in the ignition system can cause a spark loss. What's the serial number of the engine?

"Yes, I understand that. It&#

"Yes, I understand that. It's just that it's such a simple system there don't seem to be that many potential failure points.

S/N 045138XF"

"The ignitor would probably be

"The ignitor would probably be the problem if the failure is anything other than a bad ground or loose wire. However, your engine is still in warranty so you should go no futher and take it into a dealer where it will be fixed for free."

I have one of these. Tohatsu k

I have one of these. Tohatsu knowingly shipped many of them with bad ignitions. (coils) I have had nothing but trouble with mine. No less then a dozen trips to the dealer under warranty and still no real fix. They finally tried to blame me for the problems that is caused by their neglect so I have stopped taking it to any dealer. The best thing is to get rid of it and buy another brand if possible.

"TG - what a welcome surprise!

"TG - what a welcome surprise! Being full time liveaboard cruisers we often forget about warranties - we move around so much we lose track sometimes ....

I'll see if I can make arrangements with one of the two listed factory authorized shops here in Miami tomorrow. They're both closer to the airport than to where we're anchored, but maybe we can work something out. Thanks for your help.

Mark"

"Mark,

If you can't get

"Mark,

If you can't get it into service let me know. I can send one to you under warranty if you are willing to change it out yourself."

"Thanks for the offer, TG, and

"Thanks for the offer, TG, and I might just take you up on it. One of the authorized dealerships here in Miami has shut down their service dept. for a week for inventory <!?!?!> and the other's mechanic is in class today. Then there's the issue of getting the outboard about 5 miles inland to the shop...

At any rate, maybe you can help me with another issue I've had with this engine. We use it primarily on a 10' Trinka hard dinghy and occasionally on an 8' inflatable. On both boats it runs fine in flat water. But when the wind picks up and it gets choppy, it wants to quit. So far it has always restarted and, with a bit of messing with the choke, we've managed to get back to the boat. I've read that the angle of the engine may have something to do with this. Seems to me, however, that with the bow-up and bow-down motion of the dinghy bobbing over the waves the angle wouldn't have much to do with it. Especially since it runs so well in flat water. Are you aware of anything I can do to minimize the stalling issue?

Thanks again,

Mark Kaynor"

"It's almost certainly the

"It's almost certainly the angle of the engine on the transom. As the fuel sloshes around inside the tank it periodically sucks air into the fuel pickup. That fuel pickup is very sensitive to the trim angle. Tilting the engine out or in one pin hole in rough water conditions will probably cure the problem. Keeping the tank as full as possible will also help alleviate that issue for you. Keep in mind that the engine needs to be in trim under power rather than at rest. So what looks like the correct setting, at rest, with no one in the boat, is very different from being under power with weight in the stern. The trim angle, on all outboards, is adjustable so that the engine can be adapted to fit an infinite variety of applications. Or, there may be something actually wrong."

"Once again, thanks for your i

"Once again, thanks for your input. I'll go ahead and mess with the trim angle. Is it possible to retrofit this engine to an external fuel tank? "

"Mark,
don't waste your t

"Mark,
don't waste your time with the trim. That is an excuse that tahatsu uses trying to blame their mess on the boat owner or his boat. Like I said I have one that has all the same problems you are having and more which you will also have if you use it very much. Do not let them talk you into changing the jets. That is the hair brain fix they try and pawn off on you about the motor stalling. It WILL NOT fix the stalling out. You will notice that it does this when the tank gets about one half empty or a little less. The problem is with the fuel shut off valve, not the trim. The valve is a piece of junk. Also Down the road the motor will start to over heat and even explode at the oil plug. One night on the river I thought I was going to have to jump over board because of it. This is due to a VERY poor cooling system. The water pump has to be changed annually or sooner if the motor is used very much. They will try and blame you if this happens by saying that you let a plastic bag get caught at the water inlet. Just get rid of it and save yourself a bunch of grief."

"I also have the very same mot

"I also have the very same motor,and I am very pleased with it.Have used it in very choppy water on a 12 foot jon boat.No problems."

"It was the igniter. Thanks f

"It was the igniter. Thanks for all the help - this list is a great resource thanks to folks like the Tohatsu Guru.

Although, I must say that if it hadn't been a warranty repair (by 3 weeks!!) I'd have had a hard time swallowing paying for an electronic part that costs 25% of the engine when it was new.

Mark"

"Crazy isn't it? But, keep

"Crazy isn't it? But, keep in mind it is taking the place of points, condenser and ignition coil(antique designs) or exciter coil, trigger coil, ignition coil and CD module(most current designs). As outboards become increasingly advanced the electronics are becoming concentrated in very expensive single modules. In theory it makes an engine more reliable as there is less potential for defective failure...But, the costs are becoming insane."

"Mark,
like I said they put t

"Mark,
like I said they put these engines out KNOWING of the problem. You are correct. The cost is totally out of line. It has nothing to do with what they do. Simply a money making scheme. Get rid of this engine or you will see more problems if you use it very much."

"John,
I also have a 3.5 that

"John,
I also have a 3.5 that I dropped in the lake totally submersed, took it out of the water attached it to boat and it started right up.Did not change the oil for at least 6 months.Also ran some dirty gas for a while, just drained carb bowl, and to this day it runs like new.Sounds like you have issues, take your own advice, buy a different motor, and pollute their website.
Mike"