Flame Arrestor

[richterolds]

I need to reduce the height of the Flame arrestor on my 5.0 2bbl because it just contacts the engine cover. The marine tech installing the engine for me asked me to remove a few of the plate baffles, but I thought that might restrict the airflow. Then I thought of taking the rise out of the arrestor but I think it may interfere with linkages. Anyone know of a shorter one (805016)? Mercruiser said this is the only one available...

 

[GA_Boater]

Did it fit before the motor was removed? What has changed?

 

[kenny nunez]

Some of the early OMC arrestors were wider and shorter. Maybe Crowley Marine may have one . Just be sure to have your measurments that you need to clear the cover.

 

[Bondo]

Ayuh,..... I'd shim up the motorbox 1st,....

 

[alldodge]

Have a look at Sierra 18-7234 but could also post on OSO in the wanted section with dimensions needed, those guys have all kinds of stuff laying around

This is also the same size that's on my 7.4 under Merc number 805298A1
One on ebay for 79

 

[QBhoy]

What’s the K&N like ? Maybe shorter profile. Bondo has a point though...

 

[Scott Danforth]

I would clearance the engine cover

 

[richterolds]

Thanks for all the ideas. This is a repower of a Boston Whaler GTX18, and the 5.0 sits higher than it did back in 1985. The engine cover on this boat is covering almost a fifth of the stern and is not easily raised because of the lip to seal it. It doesn’t need much but maybe just taking a few plates out of the arrestor might not restrict the airflow too much. I’ve even thought of changing to a 4bbl because I was told it’s shorter than the 2. My tech told me to leave it alone though.. better off factory .

 

[garbageguy]

... maybe just taking a few plates out of the arrestor might not restrict the airflow too much...

I don't think you want to do that

 

[Lou C]

I would not mod a flame arrestor. Take a look at Holley's or Edelbrock's websites, they do sell flame arrestors with dimensions. I have a 4bbl OMC style one for the Quadrajet (which also fits the Holley I bought as a replacement) that is pretty low. As you can see its about the same height as the tops of the exhaust elbows. Not sure if this would fit your carb, what one do you have on this engine?

 

[Lou C]

PS it's interesting that you have a Boston Whaler with an I/O, that's got to be a rare boat, I have seen 2 of them over the years, both with OMC Cobras.

 

[richterolds]

Not sure of who makes the 2bbl in that 5.0 (its a 2001 out of a Larson. I’m going to go look at it tomorrow and I’ll look at those sites you mentioned. My instinct agrees with you all... pulling any plates out is probably not smart. BTW Whaler made these from 83 to 85 with either Merc 4 cylinder (190 hp) or a 5.7 V-8. I will say looks cool but a mother to work on the engine given the well Whaler made in the stern. Mine had the 4 cylinder which has driven me certifiably insane over the last 12 years....

 

[Scott Danforth]

the carb on a mercruiser 5.0 is a mercarb. it is a mercury marine carb done in conjuction with webber. it is a direct replacement for a 2-barrel rochester. same height, etc. Merc had to make this carb because GM/rochester was no longer making carbs

the manifold on your old early 80's 3.7 motor sat lower because it was a completely different motor

take a 24 grit 7" sanding disc in the angle grinder, and remove some of the fiberglass in the cover

 

[richterolds]

Wish it were that easy but Whaler built the cover out of plywood covered with upholstery. I’d have to cut the plywood and that would leave a weak spot in the middle. Could plate it I suppose but would have to pull off the upholstery...
carb height I was referring to was on the 1985 260 Merc that Whaler also offered...
My 3.7 had plenty of room in all areas.