Need explaniation Please

Javelin 353

Petty Officer 2nd Class
Joined
Dec 28, 2003
Messages
184
1991 70 hp Johnson Keep losing spark in middle cylinder on lake rpms down to @3000 temp sensor unplugged New pack and coils and wires checked all conections also.<br /><br />How does the strator and powerpack work?<br />Thanks
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Need explaniation Please

When you say it loses spark we assume you've checked it to verify. (as opposed to being a bad spark plug) It could be heat related or a ground issue.
 

Javelin 353

Petty Officer 2nd Class
Joined
Dec 28, 2003
Messages
184
Re: Need explaniation Please

Yes I pulled the wires while it was running with my hand top big zap middle no zap bottom lite zap. My be ground some time it does this while it is cold?
 

rickdb1boat

Supreme Mariner
Joined
Jan 23, 2002
Messages
11,195
Re: Need explaniation Please

Post the results, Javelin. I'm getting into the same problem with my 91' 70 HP rude... Maybe they have a common fault to save me some time...I'm dropping spark on #3...Haven't had a chance to troubleshoot the ignition system yet...Are you getting spark below 3000 RPM's? I am.. Dhadley, what grounds are most likely to cause this problem?
 

Javelin 353

Petty Officer 2nd Class
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Dec 28, 2003
Messages
184
Re: Need explaniation Please

Still waiting for the strator powerpack answer
 

reeldutch

Lieutenant
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Feb 2, 2004
Messages
1,340
Re: Need explaniation Please

the stator provides the powerpack with power. stator makes from moving magnets and stationary coils ac. this ac is being rectified by your rectifier into dc inside the power pack. not to be cunfused with the regulator.<br />this dc will be stored in your powerpack. <br />the trigger or censor coil lets the powerpack now when and for wich coil to release voltage.<br />the ignition coil steps up the voltage so you will make spark under compresion.<br />ignition coils have grounds wich could get dirty and rusty. check them to make good ground.<br /><br />basicly.
 

willamettejeff

Chief Petty Officer
Joined
Nov 15, 2004
Messages
550
Re: Need explaniation Please

It is my understanding that the rectifier is only a part of the battery charging system not the spark. Recification for spark charging is contained within the ignition pack and you've already replaced it. Suggest you check your stator as outlined in the service manual.
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Need explaniation Please

It could even be a bad / weak plug wire. We need to follow the proceedure in the OE manual for correct voltage right up to the coil output. <br /><br />The grounds on the coils always seem to get corroded or dirty. We need to clean those for sure. The pack ground is important also.
 

Javelin 353

Petty Officer 2nd Class
Joined
Dec 28, 2003
Messages
184
Re: Need explaniation Please

Should you use a washer with the pack ground my ground goes between the pack and engine the pack is plastic should i put a washer between ground wire and pack?<br />I'll check all of the other ground this weekend<br />New wires also 30 days ago <br />I try to test the strator not very handy with volt/ohm meter I check my book thanks all!<br />rb1 No spark below 3000 when acting up
 

npd4432

Chief Petty Officer
Joined
Apr 18, 2006
Messages
468
Re: Need explaniation Please

Ive read on some other posts this may be a timer base problem.
 

caper_45ca

Petty Officer 2nd Class
Joined
Jul 5, 2005
Messages
147
Re: Need explaniation Please

Hey npd nothing to do with your post, but is that a sportcraft boat?....looks very similar to mine....mine is 1985 19' fish n ski bowrider
 

npd4432

Chief Petty Officer
Joined
Apr 18, 2006
Messages
468
Re: Need explaniation Please

yes, check it out I posted some pics in the Sportcraft boats section. 1983 16' Sportcraft Sportsman.
 
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