Stock arrestor on Full Spectrum?

[Project Ski]

Has anyone put a Stock flame arrestor on an aftermarket carb like a full spectrum or a buckshot? They have the velocity stacks that are pressed in and have nothing to bolt to.

I dont want to use something like a prok due to water ingestion.

 

[robertg]

Wamiltons makes an adaptor. You have to use the single carb flame arrestors.

 

[Speedfreak]

I will be making something as soon as I get that far. I am going to run a stock air box on a set of 48mm Full Sprectrums. I don't know how just yet but after I get the engine mounted up and start piecing this boat together I will figure out something. I will post up what ever I come up with when I get it done

 

[Project Ski]

Yeah i think i am going to do the same thing. Only thing is i am running a single.

 

[parrdaddy]

I ran some stock 44 boxes on my 48 Full Specs for a while, I made some adapters to mount them on a CNC mill. They worked OK, but they made a noticeable difference on low end response compared to my K&Ns. I switched back to the K&Ns and have not really had many water ingestion problems either, but I don't do much under water stuff anymore.

I don't think I have any pictures of the adapters, I'll look and see though.

 

[Speedfreak]

I ran some stock 44 boxes on my 48 Full Specs for a while, I made some adapters to mount them on a CNC mill. They worked OK, but they made a noticeable difference on low end response compared to my K&Ns. I switched back to the K&Ns and have not really had many water ingestion problems either, but I don't do much under water stuff anymore.

I don't think I have any pictures of the adapters, I'll look and see though.

So do you think a stock air box will reduce low end response on a 850cc motor?

IF you even think it might then I won't work on an adaptor. I don't plan on playing underwater at all this year. I would hate to spend 5 hours or so building a plate and remove it after about 10 minutes.

 

[Mark44]

So do you think a stock air box will reduce low end response on a 850cc motor?

IF you even think it might then I won't work on an adaptor. I don't plan on playing underwater at all this year. I would hate to spend 5 hours or so building a plate and remove it after about 10 minutes.

You need to make one of these.

 

[Speedfreak]

You need to make one of these.

I have one of thoes but it won't work with this carb. That is what I was going to design an adaptor to fit that plate on a aftermarket carb. But it sounds like I won't need to now. Expecially if low end response it at stake here

 

[Mark44]

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I have one of thoes but it won't work with this carb. That is what I was going to design an adaptor to fit that plate on a aftermarket carb. But it sounds like I won't need to now. Expecially if low end response it at stake here

You just need the adapter that you clamp on the carbs and bolt to the plate.

 

[parrdaddy]

So do you think a stock air box will reduce low end response on a 850cc motor?

IF you even think it might then I won't work on an adaptor. I don't plan on playing underwater at all this year. I would hate to spend 5 hours or so building a plate and remove it after about 10 minutes.

I was running them on an 828cc Lamey. I won't say it's a terrible loss, but it's very noticable. Not worth it IMO since you're spending so much $$ to get the extra power. You just have to be a little more careful with the open style flame arrestors :cool2:

 

[Speedfreak]

Thanks, I will see how good I am at keeping the ski on top of the water.

If it is "noticeable" to the "seat-of-the-pants-feel" then it is a major loss in power. I have done tons of stuff that you can "maybe" feel a diference. So I don't want anything that you can feel a loss with.

 

[Powder]

Not to doubting Parr's tunning, but it could be that with the stock screens the carbs see stronger signal and is pulling more fuel and less air thus needing a rejet to get the air fuel ratio back where it should be.

How different was the jetting between the two setups?

 

[parrdaddy]

I didn't rejet, I tried them with screens and without and couldn't tell any difference between the two as far as tuning goes. From my experiences with Full Specs so far, they don't require much tuning to stay crisp. I changed them from a 5mm Lamey to a ported 701 with very minimal changes required, I think I only dropped the high jets a little.

It is possible that jetting could have helped me with the stock boxes, but everything was still crisp and responsive so I didn't make any attempts.

 

[Watty]

I'm running (have run) a stock arrestor on a set set of Novi MF 48's, and I found that you definately loose a bit of power, and yes, it is noticeable!

I found rasing the popoff due to the extra restriction on the carbs was a must, but in the end, I decided to scrap the idea and use a set of normal 46's with a stock arrestor.

An easy way to do it, is get a machined plate like Mark44 is using, and get yourself some filter adaptors. Bolt the filter adaptors to the underside of the plate, and use some 2 3/4" silicon hose that will slide over the carb throats, and the air filter adaptor on the arrestor plate. It saves you tig welding pipe on the adpator plate, and it's really neat.

I'll post a pic if you need it.

 

[Speedfreak]

[PIE]Pictures please[/PIE]

 

[Project Ski]

what do you guysthink the reason is for power loss? not as clean a path for the air to get in and down the carb? or restriction? or something else?

 

[Matt_E]

The stock arrestor lets the air in from only one direction, while the typical cylindrical a/m fa lets it in from all sides.
There might be different air flow characteristics in the carb throat because of that.
Perhaps an even flow of air from all sides pulls on the jets more consistently.

 

[Mark44]

t

[PIE]Pictures please[/PIE]

You can find anything you will need at the feed store. :biggthumpup:

Mark44

 

[Watty]

This might give you a bit of an idea anyway...

 

[oxnard111]

This might give you a bit of an idea anyway...

sweet