Why idle adjustment?

[Don Templeton]

This is not an argument, just a question. Why are most people running carbs these days and not exhaust throttles with venturi. It just seems to me that low speed idle adjustment is not needed on a racing boat. I and many very top boaters raced without carbs for a lot of years and it really seemed like a great way to go with no troubles at all. just adjust the needle and go! :-

Thanks,

Don

 

[MarkScott]

Don,

What type of boat do you run??? I'm mainly into tunnels and LOVE exhaust throttles... Running a Gardner XXL on my 3.5 K&B while there are two waiting for 7.5 boats to be made. I asked the same question in a thread shortly ago. As with you, I'm interested in why ETs are not use more..

Mark

OB Nut Racing is WFO with a WOF... ;D

 

[Ron Olson]

It's an East vs. West thing . Supposedly West of the Mississsippi prefer the exhaust throttle. Some like the better throttle respone that they give. It doesn't matter when you're running WOT anyway most of the time. It's personal preference mainly. Some of us are old enough to remember the old K&B's that had both a carb and exhaust throttle, mostly used on planes.

Wet Paint Racing; yeah, I'm that old!

 

[Slideblues]

Well I gotta say I have considered going back to Exhaust throttles,

Joe Monahan 707 Spec has a nice one for 3.5's.

Think thats why I like the older K&B carbs, barrel stop screw and main needle, Dats it

Gene ;D

 

[Slideblues]

Joes version,

 

[Don Templeton]

That looks like a pretty good setup Gene.

"OK" Well I hadn't heard any talk about them on the forum and just thought maybe there was some good reason not to use one these days. Ya, I'm that old Ron and it's been a long time since my racing days. :'( You can probably tell by the IMPBA number on my old Crapshooter. ;D

Mark, This is the set up I used to use.

 

[TimD]

The thing with exhaust throttles is they cost more. Most engines come with a carb so that is why most people use carbs as opposed to venturi's and exhaust throttles.

Another factor is they can leak oil and make the boat messier. Especially when they are worn.

The final factor is availability - hard to get them these days.

I'd love to try one on my K67 - anyone have a good Gardner XXL one they would be willing to part with?

 

[MarkScott]

Here's a shot of my K&B 13mm 3.5 OB.. I've posted this before and even put shots of a broken down 7.5 version... I've ran the Prather kit (707 model copy) before and they are messy.. But not that bad in my limited opinion...

Tim, believe the Garnder XXL units were for OB only.. Don't recall if they made a version for IB..

Mark

OB Nut Racing: Scotty, I need more POWER!!!! ;D