Got a severe misfire that I cant figure out. Clinton K751 7.5hp Seaking

[sutor623]

Okay guys I have had misfires before. Who hasn't. Anyways it is a 1978ish Clinton k751. Soooo it is a BIT%# to start every time, but when I get it to fire up it runs very well at half throttle and higher. Turn it back and it kicks(misfires) so hard I feel like Im about to blow the engine. I guess that is the beauty of single cylinder engines, there is no hiding a misfire.

I disassembled the ignition system, cleaned all the components (magnets on the flywheel were a very rusty, metal inductor (I guess thats what its called) in the center of the motor is okay, although some of the metal plates are starting to separate. Anyways parts as you know are elusive for this thing, but I am waiting on a call back from the service/parts center. I changed the spark plug out too. I have worked with points/condensers before but am not really sure about this ignition system. I have never worked on one before. So do I start with a new ignition setup or do I need to clean the carb out?

 

[mrcrabs]

Re: Got a severe misfire that I cant figure out. Clinton K751 7.5hp Seaking

cleaned all the components (magnets on the flywheel were a very rusty, metal inductor (I guess thats what its called) in the center of the motor is okay

Its called the armature, and generally they can take some separation, I would be looking for a new/used ignition setup, maybe ebay???

Sounds to me as if the coil is getting a weak charge at low rpm, could be a bad coil/ weak magnets maybe even a bad condenser or a short in the timing advance system or the carb and ignition are out of sync when your in the start up position. You definitely need the carb and timing sync in top condition so I would start there first.


I have never tried this but I have read that you can take a really strong magnet of the correct pole for each and rejuvenate the mags in the flywheel. Manual? if not check out the marshall public libray, do a forum search and you will find it.

good luck,

 

[sutor623]

Re: Got a severe misfire that I cant figure out. Clinton K751 7.5hp Seaking

Its called the armature, and generally they can take some separation, I would be looking for a new/used ignition setup, maybe ebay???

I have never tried this but I have read that you can take a really strong magnet of the correct pole for each and rejuvenate the mags in the flywheel. Manual? if not check out the marshall public libray, do a forum search and you will find it.

good luck,

Okay thanks man I will give it a shot. I didnt see any condenser. I just ran the spark plug test and the plug does not fire every rotation nor does the spark seem strong. I suspect you are correct. How exactly do you adjust the ignition timing when there are no points??

 

[sutor623]

Re: Got a severe misfire that I cant figure out. Clinton K751 7.5hp Seaking

P.S. I went to the ebsco library, there manual is not very descriptive in the ignition system.

 

[mrcrabs]

Re: Got a severe misfire that I cant figure out. Clinton K751 7.5hp Seaking

I not too familiar with the late model Clintons and I just took it for granted that it was a points model Clinton.
Then re-reading your original post that its a 1978 seaking and clinton made it the bells started ringing....Oh yeah didn't Clinton get some of there later engines from Tecumseh??? yep I think they did, So just guessing I think you may have a Tecumseh Solid State ignition model, I know they made them but you don't see that many and support is non exsitant for them except that we have a treasure trove of info on the Solid State igniton and the Tecumseh 2 cycle outboard AV817...But I need to see your engine model number and a picture of the ignition would really help . If it is the Tec AV817 SSI model engine it could be a simple....well not so simple but a very common repair now compaired to 2 years ago before we busted that one out.

Bad capacitor or a short in the pulse transformerView attachment 129567

http://groups.yahoo.com/group/eskaoutboards/

 

[sutor623]

Re: Got a severe misfire that I cant figure out. Clinton K751 7.5hp Seaking

I not too familiar with the late model Clintons and I just took it for granted that it was a points model Clinton.
Then re-reading your original post that its a 1978 seaking and clinton made it the bells started ringing....Oh yeah didn't Clinton get some of there later engines from Tecumseh??? yep I think they did, So just guessing I think you may have a Tecumseh Solid State ignition model, I know they made them but you don't see that many and support is non exsitant for them except that we have a treasure trove of info on the Solid State igniton and the Tecumseh 2 cycle outboard AV817...But I need to see your engine model number and a picture of the ignition would really help . If it is the Tec AV817 SSI model engine it could be a simple....well not so simple but a very common repair now compaired to 2 years ago before we busted that one out.

Bad capacitor or a short in the pulse transformerView attachment 129567

http://groups.yahoo.com/group/eskaoutboards/

Dude your awesome. Let me get some pics for ya.

 

[sutor623]

Re: Got a severe misfire that I cant figure out. Clinton K751 7.5hp Seaking

Havent had a chance to pull the flywheel again. But you are correct in that the motor even says solid state ignition. I was wondering why things just didnt look familiar to me.....

 

[mrcrabs]

Re: Got a severe misfire that I cant figure out. Clinton K751 7.5hp Seaking

I think your Solid state is just not putting out constant fire at cranking and idle speed, they should start popping good at about 235-265 rpm, The old capaicitor is just giving up the ghost slowly but surely, so before you hurt something else PM me and we can talk about options for that, join the yahoo group and read Eds pdf if you like and If your handy with soldering Iron, dremel and small torch its a DIY fix. The inline module is also available to save that step if need be.

 

[sutor623]

Re: Got a severe misfire that I cant figure out. Clinton K751 7.5hp Seaking

I think your Solid state is just not putting out constant fire at cranking and idle speed, they should start popping good at about 235-265 rpm, The old capaicitor is just giving up the ghost slowly but surely, so before you hurt something else PM me and we can talk about options for that, join the yahoo group and read Eds pdf if you like and If your handy with soldering Iron, dremel and small torch its a DIY fix. The inline module is also available to save that step if need be.

Alright Mr. Crabs, thanks for all your help so far. Ed from Eska on Yahoo confirmed that I definately do not have an Eska type ignition system. I checked the resistance from plug wire to ground and it is 7k ohms, which is right on spec. Magnets have a full charge. Do you think there is possibly some varnish in the low speed carb jet and that is contributing to the misfires? Although when I spun the motor over, it did not seem to get a consistent blue spark. Clinton has told me that the ignition is NLA, so basically, I feel as if this motor is soon becoming a parts motor, which is a shame, because the cylinder holds 110PSI of compression.....

 

[mrcrabs]

Re: Got a severe misfire that I cant figure out. Clinton K751 7.5hp Seaking

Ater looking at the pics of your ignition I can only conclude that this is a early form of the atom chip, I guessing that a clinton/eska type coil will work on the armiture and the electronics can be replaced with one of the many atom knockoffs out there. I' still looking at the situation but I pretty sure that will be the answer.

I have one question....does the stator have a mechanical advance linked to the carb,

Pete this looks like a form of B & S magnetron ignition system, show me where that seconed red wire goes..

http://www.milfordpower.com/GENUINE-TECUMSEH-36344A-IGNITION-COIL-p/36344a.htm if your coil is setup like this one you have it made, those coils are common.
B & S use to ship a points replacment part to do away with them, I just thinking Clinton jumped onboard thinking this was the easy way out of ignition troubles,

 

[sutor623]

Re: Got a severe misfire that I cant figure out. Clinton K751 7.5hp Seaking

Hmmm, mechanical advance, dont think so. All that I can see is one linkage from the armature assembly that goes down to the carb. It does not look adjustable to me. The second red wire coming from the black box has a wire anchor on it. I am assuming that you can use that module on a 2 cylinder model as well. It has crossed my mind to run that wire to the coil, and separate the old one, but I dont want to reassemble the engine for a trial run if I am not confident with it. It looks like the ignition that you sent me a link to has an easy way to wire it up, seeing as the male terminals on it are easy to get to. It may be the ticket. Do you know what that black box in my ignition section is? Is it an ECM? Ed Stolley seems to think that there may be a capacitor in it, and if there is that is the first thing to fail in the solid state ignition systems.

 

[steelespike]

Re: Got a severe misfire that I cant figure out. Clinton K751 7.5hp Seaking

Could this be a lean sneeze? motor runs smooth then suddenly a sneeze that may cause the motor to kick a bit then smooth again and another kick?

 

[sutor623]

Re: Got a severe misfire that I cant figure out. Clinton K751 7.5hp Seaking

Could this be a lean sneeze? motor runs smooth then suddenly a sneeze that may cause the motor to kick a bit then smooth again and another kick?

I wish man. This thing wont hardly run at all. It misfires like crazy. The ignition system is very different than most are used to. It doesnt use points, it is solid state, and irreplaceable. Me and the guys are working on a new design to get the motor back up and at 'em.