OMC Cobra 5.7 new starter much larger than the original

[Atleastitfloats]

I have an 88 Bayliner Trophy. 5.0 engine was replaced with a 5.7 engine 5 years ago, so no identifying numbers where the manual says they should be. The starter gave out, so I order the replacement Sierra 18-5905. It is much larger than the original. Bolt pattern appears the same, but starter is about twice the diameter. Solenoid stands about 1 inch taller off starter. Is this thing going to fit? I'll need longer bolts for sure. Not sure what next to do?d

Anybody have suggestions ? Thanks.​

 

[Atleastitfloats]

Here's an update. It appears my original starter was OMC 3860566. The Sierra starter 18-5913 looks the same. The catalog says 5905 is equivalent, although they have a different number of teeth on the pinion gear, 9 vs 11. Not sure if I should return the 5905 and find a 5913.

 

[Bondo]

Ayuh,.... My guess is the new starter is an ole style, 'n the smaller starter is a permanent magnet starter,....

So long as the bolt pattern is the same, they'll interchange,....

New Starter bolts are always a Good idea, but use Starter bolts, not plain ole bolts,....

I use nothin' but the permanent mag starters anymore, as it's easier to install,...
n more powerful,.....

 

[Redrig]

Ayuh,.... My guess is the new starter is an ole style, 'n the smaller starter is a permanent magnet starter,....

So long as the bolt pattern is the same, they'll interchange,....

New Starter bolts are always a Good idea, but use Starter bolts, not plain ole bolts,....

I use nothin' but the permanent mag starters anymore, as it's easier to install,...
n more powerful,.....

Yup , sounds like you received an old style starter.

I would send it back and find a newer PMGR as they are lighter smaller and more powerful . Plus the wiring is different to them , the main hot wire has to moved depending on what style you use .

 

[Bondo]

Plus the wiring is different to them ,

Huh,..??..??

Should be the same,.....

 

[Redrig]

Bondo ,

I have upgraded 2 old fords from an older style starter to a new PMGR and the diagram above is what I was referring to. (just a quick goole search and I found this diagram but it explains it better than I can )

Do you not have to change the wiring on a PMGR marine starter ?
Do the new PMGR marine starters not have the soleniod on the starter itself ?

if thats the case , then you would not have to change any of the wiring. but if the soleniod is on the starter , and you dont move the main hot wire , it will crank all of the time if you go back to an older style starter.

All of the marine PMGRs I have seen have the soleniod on the starter..... so thats why I mentioned the wiring would have to be changed .

sorry for the hijack.

 

[Bondo]

I have upgraded 2 old fords from an older style starter to a new PMGR

Ayuh,.... The OP, 'n most other boat motors are Chevys, which have Always had a starter mounted solenoid,.....

Generally speakin', there's No wirin' changes when goin' from the ole big heavy starters, to the new lightweight small starters, provided they both have starter mounted solenoids,....

 

[Redrig]

yup , my bad .

I see 5.0 and I always think 302.

OP , disregard my wiring talk .... but still ....get a new style starter for reasons mentioned above

 

[MRS]

Get the one that you had on in the first place.

 

[Lou C]

Just make sure that the bolts you use are the right length. If there are dimensional differences between the starters and the bolts are too long they may bottom out before adequately clamping down on the starter. This can allow slight movement under starter torque and that can break bolts or even starter housings.