1989 Force 50 owner says "needs a CDI"

JoshT

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Jun 2, 2012
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13
I'm looking at a 1989 Blue Fin Spectrum 1700 for sale here locally that is equipped with a matching (I assume original) Force 50. If it helps it is a US Marine Power Force 50 and the model number is 507Y9B. According to the sale flyer attached to the boat the motor "Runs good but needs a CDI ($200 online)." I haven't talked to the owner to find out more details yet, and was hoping that yall might be able to shed some light on what this $200 CDI part might be before I do. To my knowledge of ignition systems in general CDI would stand for Capacitive Discharge Ignition, which would be a style of ignition system not a part of one.

Is there any thing I should be on the look out for with this motor. Anything I should be paying particular attention to or listen for while on a test run.To that end the motor will be the deciding factor in whether I buy this thing or not. If I get this boat I don't want to have to sink a lot into this motor, to get the thing usable. I'm fully capable of rebuilding an engine done it on cars, a jet ski, and aircraft engines, but I'm not interested in doing it to get this thing on the water. I don't mind replacing small parts like a coil or something of that nature, but I want to be using it not collecting parts and fixing it for the next year. If it this motor makes it through the next two seasons I'll be happy, in the mean time I'll be keeping my eye out for a good deal on something else. Preferably a newer 50 to 75 hp 2-stroke with power tilt and trim.

Any information I can get will be appreciated so I can make a more educated decision. If it is anything to do with common problems and their solutions that's be especially helpful. I'd love to spend more time reading the forums and discovering ore for myself, but with my current work schedule I'm heading into work by 2:30 am, getting about 6:00 pm, and need to be in bed by 8 or 9 (you can see how well I'm doing that). I really don't have the time available to do the reading and research that and I probably need to make a move on this thing by Friday (federal payday so everybody else looking at it will be making their move as well). Hoping that I might be able to talk to the owner and get a test ride (or at least a run on the ears) over the weekend, just want to know what I can before then.
 

Jiggz

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Oct 23, 2009
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3,909
Re: 1989 Force 50 owner says "needs a CDI"

There are signs in your post that definitely don't make a whole lot of sense. " Runs good but needs a CDI ($200 online)." Anytime a CDI ignition system equipped engine has a bad CDI there is no such thing as running good! And that my friend is the truth and nothing but the truth.
 

JoshT

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Jun 2, 2012
Messages
13
Re: 1989 Force 50 owner says "needs a CDI"

There are signs in your post that definitely don't make a whole lot of sense. " Runs good but needs a CDI ($200 online)." Anytime a CDI ignition system equipped engine has a bad CDI there is no such thing as running good! And that my friend is the truth and nothing but the truth.

I fully agree in the sense in the general sense that it's not going to run good with bad ignition parts, but still don't know what a CDI is. Maybe the owner means it Ran good before the CDI went bad? Hard to tell. Even harder to tell if the CDI (which I still don't know what is) is bad or if it is something else. So back to my first question What is a CDI? Depending on that I might not mind fixing it.
 

Frank Acampora

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Jan 19, 2007
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12,004
Re: 1989 Force 50 owner says "needs a CDI"

Never mind what a CDI is: Walk away or buy the hull as if it had no engine--that is at a price for hull and trailer only.

As stated above the engine can NOT run well if it needs a "CDI" so either the owner does not know what he is talking about or is trying to take advantage of a buyer.

CDI does indicate a Capacitor Discharge ignition system with multiple components: Stator, Trigger, CD box or switch box, and coils. any or all can be bad.

If the engine has good compression, it can be easily fixed with bolt-on CDI components. If compression ratio is poor, then a rebuild is needed.

However: Boats for sale are a dime a dozen. Why buy one with a known problem? Why waste valuable boating time on diagnosing and repairing?

I was in your position before I retired: I worked 12 hours 7 days, got up at 4 am and arrived back home at 6-7 pm. Not a lot of time to do much else.
 

JoshT

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Jun 2, 2012
Messages
13
Re: 1989 Force 50 owner says "needs a CDI"

Never mind what a CDI is: Walk away or buy the hull as if it had no engine--that is at a price for hull and trailer only.

As stated above the engine can NOT run well if it needs a "CDI" so either the owner does not know what he is talking about or is trying to take advantage of a buyer.

Was wandering if a CDI was a particular part of the system or was the entire system as I thought. That's the way I'm figuring it, but I don't even know what the value of a hull and trailer would be. Owner is asking 1900 for the boat as is. I wouldn't mind buying a hull knowing it needs an engine, but I'm sure not paying that much for it. Made a post here in the Blue Fin Boats forum, looking for more info on these boats in general. Any ideas on what I should offer on this thing.

Got that much, thay's why I'm trying to find more information before talking to owner. As it stands right now if I want it I need to have the engine checked out first. Don't mind so much buying a project I know is a project, but don't want to buy something thinking I'll be able to use it and find out that's not the case.

CDI does indicate a Capacitor Discharge ignition system with multiple components: Stator, Trigger, CD box or switch box, and coils. any or all can be bad.

If the engine has good compression, it can be easily fixed with bolt-on CDI components. If compression ratio is poor, then a rebuild is needed.

That's the information I was looking for. Since I'm not real fimilar with 2-stroke motors what would be good compression numbers for one of these? I don't mind a little work but as mentioned don't want to be replacing the motor on a new (to me) boat.
 

Jiggz

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Oct 23, 2009
Messages
3,909
Re: 1989 Force 50 owner says "needs a CDI"

Compression pressure usually runs 115~145 psi with no more than 10% difference between any readings. Others take the difference up to a maximum of 15% but the regular is 10%.
 
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