M70a2 ignition

philipjames5k5 · Apr 5, 2012

i recently purchased a boat the a 70 hp tohatsu. i cleaned the carb and changed the plugs and im still not getting spark engine sat for about 8 months. how should i go about trouble shooting this. and i may need to be walked through some of these tasks as im new to boats.

pvanv · Apr 6, 2012

Re: M70a2 ignition

Start by understanding that your motor is at least 20 years old, and obsolete. So beware the money pit. Then, knowing that, you need to get a Factory service manual, and you will need some basic tools (including a good analog ohmmeter) and mechanical understanding of how it is supposed to operate. Maybe a neighbor or friend can help. For instance... the carbs do not affect ignition... so, if there wasn't any spark, why check into the carbs?

To get very basic, I would ask whether the stop clip is attached, (assuming you have remote control).

philipjames5k5 · Apr 6, 2012

Re: M70a2 ignition

i do understand the engine is old, but id hate to not give it a chance. as far as the ohm meter ill get on that. but what stop clip are we talking about. where would i look to see if its connected or disconnected. while im waiting for a reply ill try to do some google searching

pvanv · Apr 7, 2012

Re: M70a2 ignition

Is this a remote controlled motor, or tiller-steered? If RC, there needs to be a stop lanyard/clip under the stop button of the RC box, or ignition is disabled.

TOHATSU GURU · Apr 7, 2012

Re: M70a2 ignition

You need the factory service manual in order to get the test values and procedure to check the ignition system.

philipjames5k5 · Apr 8, 2012

Re: M70a2 ignition

is there a good place online where i can find the service manual. i searched and found nothing for the m70a. and for the stop switch there is no clip, can i put anything under it for to hold it out or must it be this clip thanks.

pvanv · Apr 9, 2012

Re: M70a2 ignition

philipjames5k5 said:
is there a good place online where i can find the service manual. i searched and found nothing for the m70a. and for the stop switch there is no clip, can i put anything under it for to hold it out or must it be this clip thanks.

The manual is obsolete, but I have a reprint available. Anything will work for the clip, but best to have the real item. Drop me an email at the office, and I can help you out. paul@obersheimersails.com

Sea Rider · Apr 9, 2012

Re: M70a2 ignition

Meanwhile pull switch knob with fingers and roll tight a thick wire or rope around circular groove, start engine, good luck!!

Happy Boating

philipjames5k5 · Apr 9, 2012

Re: M70a2 ignition

ok it fired up fine on first turn. i noticed the shift lever was disconnected where the rod goes into the lower unit. looks like the pin is gone. tried to take the lower unit off but seems like it is hung up on the drive shaft. is there anything special about taking it off. also if the pin fell off and into the hole where the rod is going to the lower unit will this hurt anything or do i NEED to get it out. thanks for all the help with the ignition.

pvanv · Apr 10, 2012

Re: M70a2 ignition

The correct clip is Part# 353068210M, complete with lanyard. $15.17. Available from any dealer, including me. There is a brass shift rod coupler that uses 2 stainless roll pins (one on each end). Is that what "fell out"? If so, there isn't any danger that it fell anywhere critical. But you may need a new coupler, of the hole in it is worn. If the coupler is disconnected and the LU won't come down, you probably have a stuck driveshaft (splines stuck in the crankshaft). If so, put wedges between the LU and the exhaust housing, and be patient. That could take days if really stuck.

philipjames5k5 · Apr 10, 2012

Re: M70a2 ignition

ill try to upload a pic of the shift rod today

M70a2 ignition

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