CDI Trouble Shooting. and Maintenance Free Batt.

[BugF]

OK Got the jumpers and working on DVA meter , Had Batt. tested today 12.85 V 683 CCA Rated 750CCA . This Batt. is a Maint. Free batt. CDI TBShoot says Maint. Free not recommended, " WHY?" 1976 Mercury 150 "1500" Think on the right path now and maybe Trigger, Cause Have fire on all Cyl's but wont run. Compression test today 1/2 - 118 3/6 - 120. My question is what is the effect of a maint. free batt. on this system. Thanks

 

[wired247]

Re: CDI Trouble Shooting. and Maintenance Free Batt.

You have no voltage regulator on the motor. It will charge to 15-16 or more volts and fry that maintenance free battery. An old school lead acid battery will just run low on electrolyte if you overcharge it. Refill the water and good as new.

 

[BugF]

Re: CDI Trouble Shooting. and Maintenance Free Batt.

Ok thanks , Was thinking of running Radio and some lights off the aint. free batt. get mait. batt. for cranking.

 

[Chris1956]

Re: CDI Trouble Shooting. and Maintenance Free Batt.

BugF, An unregulated system will boil off a bit more battery water than a regulated system. Since normally you cannot refill a Miant-free battery, they are not recommended. Look under the decals on the battery top. A lot of these decals hide the fill caps. Pry them out and add distilled water as necessary and run the maint-free battery w/o worry.

The charging system on that motor is at most 9A, at full throttle. It will not be an issue. Wired is exaggerating the effect, IMHO.

It would appear you have issues with ign on that 1500? If it has spark, then either spark is out of time or you have lack of fuel. Trigger will affect spark to all cylinders. You are choking the crap out of her when cold starting, right?

 

[wired247]

Re: CDI Trouble Shooting. and Maintenance Free Batt.

The charging system on that motor is at most 9A, at full throttle. It will not be an issue. Wired is exaggerating the effect, IMHO.

Mine ran right up to 16 volts at anything over 3500 RPM. There is a reason they don't recommend sealed maintenance free and especially Optima style gel batteries.