yamaha 25 1980s ignition fault

[stigoftd]

i have just braught this engine as a spare or repair jobie [date is a guess]
the guy selling it said he could only get spark on one cylinder so thaught it would be a quick points clean connections check but i can only get a weak spark on the same cylinder so i swaped over the condensers and tried again thinking it may be a faulty one still the same
i have disconected the stop switch no different
i have also checked both plugs and both coils and all the same
the pulsar coil is a one for both set up could it be this faulty on one side ?
or have i overlooked something ?
unsure of the model no as the brcket has been changed so cant rely on the plate no ?
also anyone know of anyone round plymouth who breaks outboards or does a decent repair service - advice ?
ime a bit stuck

[bartiny]

Hi, if you have been playing with the points then you really do need to re-time the engine this has to be done with a dial gauge and can be a real PITA to get right.

If you need instructions on how to do this then I will dig my manual out and photograph the relevant pages for you.

If you still have a problem then I may be willing to part with 1 or both of these









These are second hand off my own engine, I got a deal on a new set that I could just not ignore, so removed these and fit the new setup, I was keeping these as a back up, as I have decided not to carry an aux I am going for ultra reliability (as much as I can anyway) that is why I fitted new, but in reality I do not think I would ever need these as spares (should not have said that)
Anyway if you need either or both just make me an offer and we can go from there.

[stigoftd]

wow just the same as i have i have managed to spend 4 hrs today at work trying to find something the same without any joy and up you pop with just the thing
with the timing setting [never done it yet on a outboard] how is this set ?
otherwise i have tested the pulsar coil and it has contenuity across just about everything does this sound normal ?
and can get one coil sparking perfect just cant get both to the other has a weak spark but no where near as good as the other one and have tried every combination and have so far found both plugs - condensers - coils and connectors to be fine also the stop switch working fine and the charge coil working fine just dont know how to check the rest of the gubbins

although i did find this and thaught it would be good to be rid of the points but dont know if it will work ?
Complete Stator Plate Coils ~ Yamaha/ Mariner 20HP 25HP Outboard 1980s-90s | eBay

and a bit pricy lol

what sort of money would you want for your set of parts and p+p ?

many thanks for the advice and a pic of your manual with the timing would be great

[bartiny]

Hi I will go and find my manual now and post pics, the unit you posted link for I think you need a CDI unit for but not 100% others will know for sure.

[bartiny]

As promised.







If you have problems reading these pages try accessing them from a mobile phoine or tablet you can zoom in alot better then.

If you need owt else let me know.

[bartiny]

once you have set it up as above I think yuou will find that it will run fine and you wont need owt

Oh and do a compression check!

Good luck.

[stigoftd]

thanks for that
any idea of where i would sourse a guage similar to the ones there in the pic
never heard of one lol
give me a diesel anyday

[bartiny]

I used one of these;

401120 0-10MM Precision Outer Measuring Metric Test Dial Gauge Gage Indicator | eBay

But you have to fix it securely in the bore somehow, what I did was to saw the thread bit off a spark plug wrapped a bit of tape round the end of the dial gauge screwed the threaded bit of spark plug into the spark plug hole and then pushed the dial gauge into it worked a treat but fiddley.

Just take your time do it step by step you will be fine, these are super engines providing that the compressions check out.

[stigoftd]

many thanks for the info ime going to have a fiddle with it narer the end of the week [when the kids are out of the way
one last thing - what mode no engine is this as mine has a replacement clamp bracket on and i cant rely on the stamped plate to be correct ?
thanks again and ile up date with how i get on

[bartiny]

Originally Posted by stigoftd

many thanks for the info ime going to have a fiddle with it narer the end of the week [when the kids are out of the way
one last thing - what mode no engine is this as mine has a replacement clamp bracket on and i cant rely on the stamped plate to be correct ?
thanks again and ile up date with how i get on

Might not be much use as mine is a Yamaha Mariner but its a 25c 695.

One last thing for now check the fuel pump diaphragms as its an old engine and if any sign of weakness/delamitation/hole and you will never get it to run right.

[bartiny]

Have a read of this listing could be a source for spares?

Breaking Yamaha/mariner outboard 20-30-40hp, flywheel. | eBay

[bartiny]

Last message for a while dont want you thinking I am a stalker!!

Photos below showing what I did with the dial gauge.





Basically what you are trying to achieve is for the points to just break contact when the piston is 3.35mm or 0.132in before TDC for each cylinder.

Sounds simple but takes abit of patience, the dial gauge does a complete 360deg. for each 1mm.

Hope all that makes sense

Good luck

[stigoftd]

i have just spoken to a few out board mechanics and they have said it probably is the pulsar coil braking down
but also wanted a min of £70 to diagnose
so looks lie i will be doing it all by myself ime going to whip of the coil tonight and see if i can test it and also swap the points over just incase i there is a duff one there other than that i will then know that everything else is working as it should then ile do the timing [when i can get my brain in to complicated gear ]
have you a price for your parts if i needed them ?
many thanks again [chris]

[bartiny]

As far as I know a pulsar coil is found on a CDI ignition system not points your coil is a shared primary then seperate secondary's.

What problems are you having ie; will it start, does it miss fire, will it not idle, you get the idea

[bartiny]

To be honest at the end of the day you could easy spend £70.00 on bits you might not need, it could be money well spent having it diagnosed.

Anyway a couple more pics that might be usefull











HTH

[stigoftd]

it will start easily but only on one cylinder there is a good spark on one plug and a very weak spark on the other
this one has realy got me confused as everything seams to be set up right and clean
BUT tonight i may have found the problem
i removed both the ht coils to test found both ok then i noticed one was a cdi coil and one was not and the one with the cdi ime assuming is taking alot of the load out
so when i have been changing the input wires from one coil to the other the problem has still been there so i tried each seperatly so disconnected the cdi one and the other now has a perfect spark then connected the other input wire to the non cdi it has perfect spark then tried the same on the cdi one and very weak spark then tried both together one very weak and the other ok but not what it was
so i have one cm61-25 + correct coil sparking perfect
and 1 cm61-26 cdi coil verry weak and reducing the proper coil
so all i need now is another cm61-25 coil god help me find one

[bartiny]

Nice one now you know why I would not give you a price for what I had you would have been wasting your money.

Interesting about the coil I cant see why it has to be an exact match as long as the mounting holes are the same, same handed, and it is a points coil but someone will know for sure strange that nobody else has offered any advice yet, still time though.

Just looked at my coils and 1 is the same as yours but the other does not have any numbers or markings at all?

I posted a link earlier to a guy breaking a Yamaha Mariner (same engine) send him a message with what you want.

Lets hope that sorts that for you.

[stigoftd]

i just couldnt figure out why i was only getting one good spark no matter which way round they were wired untill i disconected the cdi one it was making my head hurt
i sent a message to that one on ebay asking about the ignition side of things but think it is a cdi one by the loks of the pic just awaiting the reply
i have found one in the us for £20 ish just awaiting reply on shipping

[HughN]

Originally Posted by bartiny

But you have to fix it securely in the bore somehow, what I did was to saw the thread bit off a spark plug wrapped a bit of tape round the end of the dial gauge screwed the threaded bit of spark plug into the spark plug hole and then pushed the dial gauge into it worked a treat but fiddley.

Other (low tech) options include:

Using a TDC-finder tool:
- move it away from TDC and make a mark on it and the flywheel
- move it past TDC until it is back to the mark, mark the flywheel
- TDC is halfway between the two marks on the flywheel

Making a manometer-style gauge (using a sawn-off spark plug or similar). The 'gearing' is the ratio between the cylinder bore and the i.d. of the tube used, so a 60 mm bore and 4 mm tube would give 15 mm change in column height for each 1 mm moved by the piston. Use two readings, as above

[bartiny]

Originally Posted by HughN

Other (low tech) options include:

Using a TDC-finder tool:
- move it away from TDC and make a mark on it and the flywheel
- move it past TDC until it is back to the mark, mark the flywheel
- TDC is halfway between the two marks on the flywheel

What do you mean one of these?

Making a manometer-style gauge (using a sawn-off spark plug or similar). The 'gearing' is the ratio between the cylinder bore and the i.d. of the tube used, so a 60 mm bore and 4 mm tube would give 15 mm change in column height for each 1 mm moved by the piston. Use two readings, as above

Not a clue what you have just said

Move the piston back 1mm and the dial gauge shows wait for it........1mm WOW.