Outboard CDI Units

[benfordboy]

Ok not really a Sewertube Canalworld topic , but there are more than a few knowledgeable folks on the forum who may be able to offer an opinion (And plenty of others who may too )

 

A old Honda BF15 outboard with CDI problems - CDI available from Honda UK at a price that rivals gold by the ounce. Similar part from the USA at the price of Silver.

 

Or a Motorcycle CDI at the price of Scrap Steel !

 

IIRC the BF15 is a twin cylinder that is in effect a 'Big Bang' motor - ie a twin that both cylinders fire together (Single spark) so - Would a Single cylinder CDI unit (ie off a motorcycle) work ?

 

Plenty of CDI's available that fit the part on the internet - same plug fitting etc (The late Honda's have decompression & rpm advance , but I dont believe the early ones have)

 

IMHO - Fitting a 'pattern' CDI shouldnt cause any damage , it just wouldnt run correctly ?

 

Answers on a postcard , or the forum !

[Arthur Brown]

Limited experience with mid 70s outboards was that the CDI units were thoroughly encapsulated in resin, whether yours should be, and whether the automotive ones are encapsulated only you will know.

[benfordboy]

Limited experience with mid 70s outboards was that the CDI units were thoroughly encapsulated in resin, whether yours should be, and whether the automotive ones are encapsulated only you will know.

 

Yes they are & look almost identical !

[Tony Brooks]

Ok not really a Sewertube Canalworld topic , but there are more than a few knowledgeable folks on the forum who may be able to offer an opinion (And plenty of others who may too )

 

A old Honda BF15 outboard with CDI problems - CDI available from Honda UK at a price that rivals gold by the ounce. Similar part from the USA at the price of Silver.

 

Or a Motorcycle CDI at the price of Scrap Steel !

 

IIRC the BF15 is a twin cylinder that is in effect a 'Big Bang' motor - ie a twin that both cylinders fire together (Single spark) so - Would a Single cylinder CDI unit (ie off a motorcycle) work ?

 

Plenty of CDI's available that fit the part on the internet - same plug fitting etc (The late Honda's have decompression & rpm advance , but I dont believe the early ones have)

 

IMHO - Fitting a 'pattern' CDI shouldnt cause any damage , it just wouldnt run correctly ?

 

Answers on a postcard , or the forum !

 

 

Have you made sure the unit's earth to the block is OK. I seem to recall this might be a weak spot on them giving all sorts of odd symptoms.

[benfordboy]

Have you made sure the unit's earth to the block is OK. I seem to recall this might be a weak spot on them giving all sorts of odd symptoms.

 

Tony

 

Unsure on that - I have access to a pattern CDI - Is it worth a try ?

[Tony Brooks]

Tony

 

Unsure on that - I have access to a pattern CDI - Is it worth a try ?

 

 

I can not say because I have never tried it. I would have thought the biggest two dangers are that it's input characteristics may not match the flywheel coils or its output characteristics may not match the ignition coil (if the coils are not in the CDI box).

 

I can't see from a theoretical point of view how either could cause more damage but who knows. On balance it is probably worth a try, but then again you need to get the wiring right.

 

The very early Mercury CDI engines still used contacts and they very occasionally closed up so anther check perhaps. I may be wrong there because it was 40 odd years ago.

[benfordboy]

I can not say because I have never tried it. I would have thought the biggest two dangers are that it's input characteristics may not match the flywheel coils or its output characteristics may not match the ignition coil (if the coils are not in the CDI box).

 

I can't see from a theoretical point of view how either could cause more damage but who knows. On balance it is probably worth a try, but then again you need to get the wiring right.

 

The very early Mercury CDI engines still used contacts and they very occasionally closed up so anther check perhaps. I may be wrong there because it was 40 odd years ago.

 

Have tried the 'Pattern Cdi'

 

Have to say , its almost perfect ! , starts & runs under load with no problems - But......... Tickover is a little lumpy , this may be correctable with a bit of a carb tweak , but I will probably replace with a genuine unit to be honest.

 

However - This is a CDI unit that plugs in straight from the box , works well under load & is a perfect unit to have aboard as an emergency 'get you home' spare.

 

The cost ???

 

£5.99 plus P&P !

 

I still cannot believe I'm the only one to try such a unit - But have trawled the Net for hours looking for someone else who has tried it to no avail !

 

Details of CDI available on request

[roky]

yes, you may be the only one on the internet to have done this, as i have been searching for days and yours is the only post regarding the use of a non-marine cdi on this honda engine -- would like the details of which one you used so i can get one myself -- thanks

[onionbargee]

I would guess it either is compatible or its not, theres no timing involved in the CDI unit itself, as long as you have the original trigger coil. Honda parts are outrageously expensive, but luckily the Chinese rip them off cheap as chips. stick anything in that works, a CDI is a CDI ?

 

i had a motorbike that ran on a CDI i salvaged off a generator.

[roky]

well, i know i can get a cdi with the 6 pins connector that match my honda for about 2% the price of a stock unit from honda, on ebay -- and i'll certainly do that, just to test my system, as i'm not sure if the fault is in the cdi internally, or the wiring(if i "wiggle" the connector, she starts) -- this is not an uncommon problem with honda cdis, but can be external or internal -- but am hoping to hear back from benfordboy as to which specific cdi he used

 

but i guess if you ran a bike off a generator cdi then theres a wide application range --

[Arthur Brown]

I used to run a IIA Land Rover with the innards of the distributor off a Hilman Imp! It worked which was good cos that was all I had to hand at the time. BUT the performance wasn't quite right!

[roky]

ah yes, "thinking outside the box" -- its the way to go, always a sense of satisfaction when one of those ideas works -- i've seen some of the greatest examples in mexico, and i'm sure in other developing countries -- sad to say, i don't see much of it any longer here in the u.s.

[bizzard]

I used to run a IIA Land Rover with the innards of the distributor off a Hilman Imp! It worked which was good cos that was all I had to hand at the time. BUT the performance wasn't quite right!

A 2a Landrover would have had coil and contact breaker ignition unless someone converted it later to electronic.

[LeakyLockDoors]

 

 

Details of CDI available on request

Hi,

 

If you still have the details of the CDI I would like to try one on mine.

 

Many thanks!

[Hayabusabart]

Ok not really a Sewertube Canalworld topic , but there are more than a few knowledgeable folks on the forum who may be able to offer an opinion (And plenty of others who may too )

 

A old Honda BF15 outboard with CDI problems - CDI available from Honda UK at a price that rivals gold by the ounce. Similar part from the USA at the price of Silver.

 

Or a Motorcycle CDI at the price of Scrap Steel !

 

IIRC the BF15 is a twin cylinder that is in effect a 'Big Bang' motor - ie a twin that both cylinders fire together (Single spark) so - Would a Single cylinder CDI unit (ie off a motorcycle) work ?

 

Plenty of CDI's available that fit the part on the internet - same plug fitting etc (The late Honda's have decompression & rpm advance , but I dont believe the early ones have)

 

IMHO - Fitting a 'pattern' CDI shouldnt cause any damage , it just wouldnt run correctly ?

 

Answers on a postcard , or the forum !

hi. a bit late. but I changed the CDI on my BF15 outboard only to discover that the problem was a sticky fuel pump! quick clean and OK..