Cleaning a Spark Arrestor

[hd2002hd]

What is the best way to clean the spark arrestor? Soak it in gas/solvent? Also, I assume it comes off without removing the manifold on 7.4's? Sure looks like a tight fit to get those bolts out.

 

[hd2002hd]

I guess I meant do you have to remove the risers, not the manifolds.

 

[Captain Allen]

Mine has one nut on top of the flame arrestor, easy to remove. I then spray it thoroughly with brake cleaner. It takes about a can per arrestor. It dries quickly, too.

 

[sbw1]

I used gas to clean them followed by soapy water and a blast with the garden hose. Have to be careful with how you do it. Opinions vary on the approach. They are pressure fit over the carbs.

 

[hd2002hd]

Mine is an EFI and has 4 bolts that are horizontal between the riser and top engine cover.

 

[Pyrojodge]

Mine has one nut on top of the flame arrestor, easy to remove. I then spray it thoroughly with brake cleaner. It takes about a can per arrestor. It dries quickly, too.

Yep, I have always done mine that same way. Easy and works very well.

 

[Adefelice]

I have the 454 horizon's and attempted this same project over the summer. Due to a recall the previous owner added the 3" riser spacers so I can no longer remove the arrestor without taking off the risers first. Will take the time this winter to remove and inspect the risers, replace the gaskets and clean the arrestors along with the throttle body.
Looking forward to hearing how you make out!

What is the best way to clean the spark arrestor? Soak it in gas/solvent? Also, I assume it comes off without removing the manifold on 7.4's? Sure looks like a tight fit to get those bolts out.

 

[Island Time Buffalo]

I have the 454 horizon's and attempted this same project over the summer. Due to a recall the previous owner added the 3" riser spacers so I can no longer remove the arrestor without taking off the risers first. Will take the time this winter to remove and inspect the risers, replace the gaskets and clean the arrestors along with the throttle body.
Looking forward to hearing how you make out!

I have the same issue, although I think mine shipped with the taller risers. It's an asinine configuration - having to remove risers and replace gaskets for a routine maintenance job is idiotic.

 

[Bt Doctur]

 

[hd2002hd]

Well, mine also has the riser extensions. I was able to pull the 4” exhaust hose off the riser and then I could get to the 4 castle nuts holding the spark arrestor on. I could then slide the arrestor 1.5”-2” out. I used brake cleaner to saturate and clean the spark arrestors inside and out. Not as good as taking them all the way off, but they are pretty clean.

 

[Island Time Buffalo]

Well, mine also has the riser extensions. I was able to pull the 4” exhaust hose off the riser and then I could get to the 4 castle nuts holding the spark arrestor on. I could then slide the arrestor 1.5”-2” out. I used brake cleaner to saturate and clean the spark arrestors inside and out. Not as good as taking them all the way off, but they are pretty clean.

I was eyeing the hose. But it honestly looks easier (less awful) to remove the riser. How much of a be-aaatch was removing the hose? Do you need Hulk strength?

 

[Adefelice]

I even contacted Merc to see if they made a 90 degree fitting to mount to the throttle body so I wouldn't have this issue in the future unfortunately, they don't. She told me to continue to do what I've been doing. (I haven't done anything)
I guess it all depends on the engine room configuration and if you have v-drives or true inboards. If the engines were turned around then the exhaust hose would be going in the opposite direction of the arrestor.
I thought about removing the 4" hose instead of risers but its time for me to inspect the risers anyway. Plus, knowing me I would probably destroy the hoses in the process.
Here is a pic of what I'm dealing with.

 

[hd2002hd]

I was eyeing the hose. But it honestly looks easier (less awful) to remove the riser. How much of a be-aaatch was removing the hose? Do you need Hulk strength?

Really wasn’t bad. I just sit on it and worked it up and down. Came right off.