Slow to crank

[Riccochet]

Serial: 2B018828
Model: 1150P73EY

2014 150 Pro XS. Motor has about 130 hours on it. Always have used DFI oil, yearly maintenance done by a certified tech, non-ethanol 87 with Don's cocktail in every tank, brand new Duracell G31 AGM startiing battery with 1000 MCA as of last weekend, fully charged. I'll pump the primer bulb and the first start of the day it just cranks very slow. To the point where it sounds like the battery is near dead and it almost doesn't want to turn over. Then, it'll fire and rev up to about 3k RPM's, but drops to idle quickly. Just had my yearly done and compression is 153 across all cylinders. Now, it's only the first start of the day. Once she's warmed up and running it starts no problem for the rest of the day.

I originally thought it was the battery. I had a G27 Interstate in there and it did the same thing, which is why I bought the Duracell G31 AGM.

Is this normal? My friends 2015 225 Pro XS does almost the same thing, but not as severe. His will at least crank with almost normal speed. He's running the same Interstate G27 that I had.

[SilverFox579]

Assuming your battery connections are clean, tight, and in proper order (engine lugs first, rest in order largest to smallest), the battery you installed may not have sufficient capacity if you're using it for anything more than engine only. Optimax engines require 800CCA/1000MCA for engine only, no accessories (graphs, livewells, powerpoles, etc). The 31AGM Duracell is rated 800CCA.

For fishing applications Don recommends a battery with at least 950CCA. See this topic for recommended batteries - "BATTERIES THAT MEET THE REQUIREMENT" - Reserve Capacity Monsters!

[Riccochet]

Assuming your battery connections are clean, tight, and in proper order (engine lugs first, rest in order largest to smallest), the battery you installed may not have sufficient capacity if you're using it for anything more than engine only. Optimax engines require 800CCA/1000MCA for engine only, no accessories (graphs, livewells, powerpoles, etc). The 31AGM Duracell is rated 800CCA.

For fishing applications Don recommends a battery with at least 950CCA. See this topic for recommended batteries - "BATTERIES THAT MEET THE REQUIREMENT" - Reserve Capacity Monsters!

Assuming I don't turn a damn thing on when first starting my boat in the morning (which I don't) then the only thing the battery is being used by is the motor to crank.

My battery is the same exact battery as the Deka 8A31 which has 800 CCA and 1000 MCA. The Duracell is a rebranded Deka.

Still would not explain why the motor struggles to start first thing, but starts fine afterwards.

[leonreno]

Could be some sort of parasitic drain on the battery you are not aware of. I would test battery with the same conditions you would normally face when starting the motor first time. Such as charged battery but leave off charger the same amount of time you would when leaving to go fishing and then test battery voltage at battery. Maybe over kill but having battery tested for capacity might help also, though it is new it should be good.

[Reel Life]

Check your battery cables....corrosion at lugs...check to see if they get warm anywhere.

[Riccochet]

I thought about that. Takes me about 45 minutes to get to the lake and launch. Even if I make my morning run and troll for the next couple hours, graphs on, livewell running, the motor cranks up just fine at that point.You'd think with all that drain the battery would be more drained that a parasitic drain over 45 minutes of trailering to the lake.

I don't know. Motor has done this since day one. No codes, no issues with the motor otherwise. Always dealer serviced, and they can't find anything wrong. Maybe just a trait of the motor.

Could be some sort of parasitic drain on the battery you are not aware of. I would test battery with the same conditions you would normally face when starting the motor first time. Such as charged battery but leave off charger the same amount of time you would when leaving to go fishing and then test battery voltage at battery. Maybe over kill but having battery tested for capacity might help also, though it is new it should be good.

[adchunts]

Following this thread, as my 175 has done the exact same thing since new. I have checked everything out as well...and replaced the cranking battery with one from Don's list. I am thinking it is just a random Merc thing...

[mcmanucr]

I have the same exact issue with a 2013 175 pro xs with 126 hours. Regular maintenance performed just like you and I just replaced my cranking battery with the 31 Batteries Plus X2 hoping to solve the problem. No luck. Have no idea why it's slow to crank on the first start of the day but after that it fires up no problem.

[JOE54]

do any of these mtrs have a batt cut off switch that the + cable goes to / if so hook it to batt post/ also RICCO your mtr should not rev to 3000 upon start up may be diapram problem in fuel rails

[QuickBullet]

Just saying....an engine which siphons fuel, OR OIL, into the crankcase while setting will certainly crank over slowly as the cyls are trying to hydraulic! Probably not your problem but worth mentioning.
Pull the plugs after setting a day or so and spin it over seeing if it's fogging fuel out of the plug holes....then at least you'll know!!

[SilverFox579]

I thought about that. Takes me about 45 minutes to get to the lake and launch. Even if I make my morning run and troll for the next couple hours, graphs on, livewell running, the motor cranks up just fine at that point.You'd think with all that drain the battery would be more drained that a parasitic drain over 45 minutes of trailering to the lake.

I don't know. Motor has done this since day one. No codes, no issues with the motor otherwise. Always dealer serviced, and they can't find anything wrong. Maybe just a trait of the motor.

This new info explains why no change with a new battery. I now suspect the problem is elsewhere and would be closely inspecting everything between the battery and engine - cables, cable terminals, engine lugs, switches, etc.

In addition to Joe's questions you might check this post in the 3L forum - http://www.bbcboards.net/showthread.php?t=792030

[Riccochet]

That's great, but I don't experience any of those symptoms except a slow crank and only the first time I turn the motor over. If it were a wiring issue where there was a loss of amperage going to the starter it would be consistent.

[bassnman81]

Mine does the same thing on a lst time cold start in the morning. It's a slow crank then fires up, speeds up for a second. Fine the rest of the day. I think it's just a nature of the beast. Always starts. I originally had the plus cable going to a perko cutoff switch and a low voltage alarm would sound on the first stop. I wired it directly to the battery and it no longer gets the low voltage alarm. These Pro XS motors are real amp and voltage critical for sure.

[EuropeanAM]

A couple of observations:

-Compression is definitely NOT 153 psi. Engine simply could not run at that compression.

-You are essentially running the BARE MINIMUM capacity battery for your engine only in terms of a battery. And... we really need to LOAD test the battery you have (do NOT rely on stickers). Don't fall prey to the assumption that it's new, as "New does NOT necessarily equal GOOD".

-Verify battery terminal connections, cables, and ENGINE END connections. This can be done by a voltage drop test, or even by load testing (which is actually as close to a real-world test as you can get without starting the engine).

-Also recommend Air/Fuel pressures be checked at idle, under acceleration, and 5/10/15 seconds after engine shutdown. You maybe leaching fuel into the air side of the system (two of your symptoms indicate this is a prudent test).

[Riccochet]

A couple of observations:

-Compression is definitely NOT 153 psi. Engine simply could not run at that compression.

-You are essentially running the BARE MINIMUM capacity battery for your engine only in terms of a battery. And... we really need to LOAD test the battery you have (do NOT rely on stickers). Don't fall prey to the assumption that it's new, as "New does NOT necessarily equal GOOD".

-Verify battery terminal connections, cables, and ENGINE END connections. This can be done by a voltage drop test, or even by load testing (which is actually as close to a real-world test as you can get without starting the engine).

-Also recommend Air/Fuel pressures be checked at idle, under acceleration, and 5/10/15 seconds after engine shutdown. You maybe leaching fuel into the air side of the system (two of your symptoms indicate this is a prudent test).

Thanks for the info! I typo'd the compression. It's 135. Every year I get a printout from my dealer/shop with fault code history, hours, compression and services performed. Unless they are lying to me. As for the battery. This is 3rd battery that's been in the boat. I went through 2 Interstate G27 marine cranking batteries (tested at batteries plus) and now the Duracell G31 AGM. Same results, so I can't say it's the battery. I checked all the connections, but maybe it's the main cutoff switch. I haven't bypassed that just to see if it's causing issues, or done a voltage drop test. I'll also have my shop do an air/fuel pressure test. Thanks for the info!

[Riccochet]

And, just curious, but my Duracell G31 AGM is the same battery, rebranded, as the Deka 8A31DTM you have listed in the recommended battery post. If you recommend it, but then tell me it could be a problem, what battery do you ACTUALLY recommend?

[EuropeanAM]

Please re-read the Batteries Thread. It was originally done by Mercury Engineering, listing batteries that MEET THE REQUIREMENT for the ENGINE.

If you look further on in the thread (especially the last couple of pages), there are a number of other batteries recently shared (and some that I have personally added to that list in the first post).

IMHO... you really need 950+ CCA in a fishing application, given the "entertainment systems" we're adding to these boats today.

[berudd]

So, hard to say if what you are experiencing is normal or not without seeing it happen but I will say that many Opti owners, myself included, report slow cranking on the first start up of the day. Especially if the weather is cold. At times mine cranks just long enough for me to wonder, we're really talking a fraction of a second here, but then fires right up. I have never checked to see where the RPMs go when it does start but I do notice it rev up a bit before settling down to idle. I've heard some say that it takes a few more cranks for the compressor to build pressure on a cold engine so that could account for some of it. QuickBullet makes and interesting point as well. And engine that has sat for a while may have accumulated fluids in a few locations that put more load on the starter. Something like that has been my guess.

We can see from the responses here that others see similar behavior. I suspect that what you are seeing is normal for these engines. Anecdotally, I'd say that Optis in general "sound" like the crank a little slower than other engines at the ramp so that probably tends to make this seem a little more obvious.

[Riccochet]

Yeah, I'm starting to think it's normal. Went out in my buddy's 2017 Ranger with a brand new Pro XS 225, new batteries, new everything as of a month ago. His was slower than mine to crank on the first start of the day. After that it was smooth, fast starting all day. Just like mine.

Chalking it up to nature of the beast.

[billproxs]

2008 with 345 hrs. Has alwsys been slow sounding to crank. Had 4 agm batteries from blue top 31s ro current battery now exide 31. I always wonder if mines week and going to start. Always on first start also when launching. Starts fine after that all day.