Yamaha 90 Power Pack / CDI Question

[bermuda8]

Hi,

I have a 1993 Yamaha 90 2 stroke that needs a new CDI box. The original CDI part number was 6H0-85540-02-00 - i need a new one and the yamaha site says to replace it with 6H0-85540-07-00 but in photos i've seen it doesn't have the right connectors. What i really want to do is find a used replacement since they cost so much. I see alot of replacements in other years with part numbers 6H0-85540-04-00 etc but can't figure out which one will be a direct replacement. Are there any Yamaha spe******ts on here that know what my options are for a used replacement part number wise? Any help would be sincerely appreciated.

Thanks

 

[Capt Ken]

Re: Yamaha 90 Power Pack / CDI Question

How did you determine the CDI was bad?

 

[bermuda8]

Re: Yamaha 90 Power Pack / CDI Question

How did you determine the CDI was bad?

Mechanic tested it....

 

[Capt Ken]

Re: Yamaha 90 Power Pack / CDI Question

In 23 years as a Yamaha tech, never seen one fail. No way to test one. It's a process of elimination.

 

[bermuda8]

Re: Yamaha 90 Power Pack / CDI Question

Thats what the mechanic said also - he said he's never seen one fail either and he's been working on them for a long time also. I have talked to one other guy with the same motor (different year though) and his failed and he had the same symptoms so im hoping that is it. I do know the mechanic went thru eliminating other issues first.

 

[99yam40]

Re: Yamaha 90 Power Pack / CDI Question

if you do not mind, what were the symptoms you had?

I take it you got the answers needed about #s on the other site you posted the question on

 

[bermuda8]

Re: Yamaha 90 Power Pack / CDI Question

symptoms were 93 Yamaha 90 2 stroke that dies whenever i put it in gear for about the first 20-25 mins of getting on the water (idles fine and revs fine in neutral) - then it will start slowly sputtering when accelerating then finally get on a plane. When i'm having this issue I can rev it up fine in neutral, its just when i put in in gear that it dies when i try to accelerate in fwd or reverse. Just dies when under a load. I got answers on the other forum - hope they are correct that the 02, 03, 06, and 07 are interchangable.

 

[99yam40]

Re: Yamaha 90 Power Pack / CDI Question

Cylinders needs more fuel to run under a load and cold, so it will run OK in neutral even it is too lean.
sounds like that would be fuel related problem or maybe timing not advancing properly.

The voltage in and out of CDI and the timing can be easily tested to make sure it meets spec.
Hard to make sure on the fuel side though

Hope a CDI will help and not be an expensive mistake

 

[bermuda8]

Re: Yamaha 90 Power Pack / CDI Question

Cylinders needs more fuel to run under a load and cold, so it will run OK in neutral even it is too lean.
sounds like that would be fuel related problem or maybe timing not advancing properly.

The voltage in and out of CDI and the timing can be easily tested to make sure it meets spec.
Hard to make sure on the fuel side though

Hope a CDI will help and not be an expensive mistake

just called mechanic and he said it wasn't putting out the correct voltage.....

 

[99yam40]

Re: Yamaha 90 Power Pack / CDI Question

So it sounds like you are headed in the right direction if there was good voltage in and bad out.

Can't put out good voltage if you do not put the good voltage in

 

[bermuda8]

Re: Yamaha 90 Power Pack / CDI Question

So it sounds like you are headed in the right direction if there was good voltage in and bad out.

Can't put out good voltage if you do not put the good voltage in

I'll post the result - wont be till end of the week though when i get the new part - thanks everyone for the inputs!

 

[Capt Ken]

Re: Yamaha 90 Power Pack / CDI Question

I'm wagering that there will be no change.

 

[bermuda8]

Re: Yamaha 90 Power Pack / CDI Question

Is there anything special you need to to when swapping out these cdi boxes? I have a replacement and the mechanic is tied up so i want to replace it myself. The only concern i have is the mechanical connector near the top of the unit - is there anything special about connecting it? calibration etc?

Thanks

 

[bermuda8]

Re: Yamaha 90 Power Pack / CDI Question

Well it definitely was the cdi = replaced it and issue went away and boat runs great now. Thanks for everyones help.

 

[99yam40]

Re: Yamaha 90 Power Pack / CDI Question

great to hear.
Make sure the timing is in spec WOT and idle.

I had to replace the CDI on my C40 that the idle timing was way off no matter what I did . I blame it on the built in wiper for throttle position went bad

 

[ters83]

Good day,

I am having a similar problem with my Yamaha 90hp.
The engine does take and idles perfectly, it also runs perfectly once I up the revs, either with the warm-up lever or by placing it in gear and opening up the throttle. However once I come back to neutral it slows down and cuts out. It will instantly start again and it will idle perfectly only to cut out after revving or placing it in gear and coming back to neutral again.

The mechanic cleaned the carburetors and played around with the air intake screws and idling screw with no avail, he seems to think it is the CDI that is failing and not regulating the timing.
Could anyone assist with:
1 - Where I can find the part as I seem unable to find it online, the part number on the CDI is 6HO CU7383, attached is a picture of the CDI as well as my motor markings. Or if it is compatible with another model?
2 - Do you agree that there is nothing else we can check or do before replacing "a very expensive" CDI ?

Thanking you in advance.

 

[GA_Boater]

This thread is closed due to waking it up after a more than 7 year nap. Start a new thread of your own and please read our rules about letting sleeping dogs lay. Or is that lie? No matter, please don't post in old threads, ters83