Honda 8

lexi

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Anyone got the resistor values on CDI . I have w/shop manual and on testing the figures I have some very high resistance values over the given ones. Just trying to make sure before I buy a new CDI unit.

Alex
 

andyball

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a waste of time testing cdi's with resistance figures - aside from it not really testing much, it relies on you using the same meter that the factory did.

IF you lose sparks when cutting out - yes could be the cdi, but don't use a resistance test to tell you to spend big money.

The trigger or source coils can break down when hot, if that ties in with your problems - they can be tested reliably using resistance figures.

I've a wealth of experience with cdi ignition issues - and failure of the box is by far the least common, tho does happen. usu total loss of sparks, forget the cdi resistance tests and prove that all other factors are ok ( source/trigger coils, any control switches etc.... ) rarely, timing can go way out & cause probs when hot, or just intermittent - easily checked with a timing light - easily that is if you can re-create the problem.
 

lexi

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Thanks Guys

If the resistance values of four or five connection test procedures on the CDI were supposed to be 0.5-10k ohm and my readings were 67k ohm would that be a fault that could cause the cutting out. If you check back the threads the probs of my engine are detailed

Many Thanks

Alex
 

andyball

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nope, even with the exact same test meter the guy who wrote the manual used, I wouldn't risk a fiver on the results meaning anything.

Sadly have terminal late night/early morning don't wanna wade through long threads - syndrome /forums/images/graemlins/blush.gif - also found in years of customers mcycles, that the longer the saga, the better it was to start from scratch re symptoms now, rather than history.
 

VicS

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[ QUOTE ]
Will keep at it.

[/ QUOTE ]

My thoughts now are. <ul type="square"> [*]If the rsestance values are different to those in the official manual you have got to suspect the CDI unit. What would be the point of publishing values if they are totally meaningless? BUT specs can change so the unit you have could be different! [*]IIRC you have already tried a diffrent CDI unit with exactly the samle troubles persisting so that makes it look less likely that the unit is faulty. BUT the one you tried could have the same fault! [*]You have eliminated the posibility of external switches such as the "in gear start" protection causing problems Are you sure about that? [*]It is really a fuel or carburation problem. [/list]

It's your call whether or not to spend a wad of cash on a new CDI unit but at the end of they day that's the only way you can eliminate it as a posibility!

Personally I think its a fuel or carburation problem. Thats the only thing I can accept as coming close to the troubles you describe. It sounds as though it is picking a bit of debris up which blocks a jet for a while before falling away again only to be picked up again a few miniutes or several hours later.

Sorry just thoughts and not a lot of practical help
 

FullCircle

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What year is the Honda 8?
I have a CDI unit, a spare carb and coils laying around from a BF75. You can borrow them if you wish.
 

andyball

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[ QUOTE ]
What would be the point of publishing values if they are totally meaningless?

[/ QUOTE ]

I wondered that many times over the years - best guess was they did it cuz dealers or management thort they shd be there - I never found any that meant a blind thing in reality; a bit like trying to test a tv by putting a meter on the aerial & mains leads.

I assume the blessed thing doesn't stay not-running long enough to test & see the spark is missing or timing is wrong?
 

lexi

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Thanks guys.
Vic- I changed the ignition coil for a s/h one but only checked resistance of the Cdi unit of which there are over 30 readings. I only wondered about the values of the CDI as a lot of them are in spec but some are way out. Also the W/M says to change the unit if they are not within spec but that may not be problem.

Thanks for the offer of lending components my friend. Took engine out today after cleaning carb again and blowing out jets with compressed air.
Used very fine copper wire strand on all jets and orifices. Also put a biocide through remote tank which I had cleaned last time out.

After having everything apart and back together engine started as usual on third pull. 200 yards from mooring it stalled instantly. It started instantly as usual and moved off.........it normally stalls a few time with load going on ........but not today . It didn`t stall for another hour. Started of course and moved away. It did this 6 or seven times through the day.............but unusually it did not do it`s usual of stalling ..starting on pull and stalling on going forward for five or six times before finally takng the load and moving off. One time on 2/3 throttle it died right down instantly to just about dead and then picked up again as quick. It also spluttered a few times which it never does. The only thing I done since last trip was put Biocide in and clean carb again.
The spluttering and the mini stall were encouraging as they are something to go on.
Alex
 

Lakesailor

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Remote tank.
Is the fuel connector a genuine Honda one @ £25 or one of the £5 pattern parts?
If it's not genuine Honda get one. The O ring in the cheap ones gives trouble and sucks air in. You can sometimes overcome the problem by holding it on by hand.
 

jonathankent

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My Honda B75 does some strange things too.... you can hear the engine noise change and revs reduce, but then if I leave it alone it will come back...... just makes me nervous with it after I had one failure already any change in noise has me twitching.
 

jonathankent

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Had that when fitting a new tank to mine.... marine shop sold me the £5 one - didn't fit properly and leaked fuel, sold me the £6 Quiksilver one and this did the same, so in the end spent the £26 odd quid and bought a genuine Honda one.... definitely better quality - its made of metal rather than plastic for a start!
 

VicS

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[ QUOTE ]
The only thing I done since last trip was put Biocide in and clean carb again.

[/ QUOTE ] I'm not sure about this biocide doing any good. I have only ever associated it with killing bugs in diesel tanks. If you have cleaned out the tank and in particular got rid of any water then I think you have done all that is necessary in that respect. Some of the behavior does sound a bit like water in the fuel though! Something to disperse any water might be more appropriate than a biocide.

If you honestly feel that you repeated efforts at cleaning the carb are making a difference then it does suggest that the problem is there somewhere. Have you checked / cleaned the fuel pump. A faulty pump wont make it die suddenly, though, just slowly peter out as the carb empties as if you had disconnected the fuel line.

Any problem with the pump or leaks in the fuel line for that matter can be overcome by pumping the priming bulb.
 

lexi

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Thanks Vic
Have cleaned and checked pump membrane..........ok. Carb is always full during shenanigans. Tanks have all been flushed previous. Added some meths to disperse any water droplets lurking.No difference in pumping bulb. Have tested that with air and primer bulb and float needle all hold good. Thanks for all advice from everyone. Will let you know what the outcome is

Alex
 

andyball

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had a quick cast thru the prev thread now.

I've come across one or two mystery cut-outs caused by metal muck from timing advance mech on rotor/trigger coil faces - Imagine you'da said if swarf there though.

had a honda car cut out rnd sharp bends- all the years of metal dust from the awful mechanical advance thing moved when err cornering hard.

also one or two naughty honda OB's where owners didn't wanna strip and see what mechanical probs lurked - these sort-of cut out at times, tho ran a bit umm roughly anyway- could never get the tickover low and smooth. Suspected valve issues; since ignition & carb all squeaky clean.
 

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