Outer Limits 4x4 Board

Hi all, new here...why did it take me so long to find this forum. Best read since the Davinci code, lol, and I've only got about 180 pages to go!

Anyway my question is about the stock 2f Carby. I've had two rigs with pretty stock 2f engines - a 45 and a 40 series. Both had extractors and the 45 was mated to a 4 speed and my shorty has a 5 speed box. The difference in power is what makes me wonder about the carby or even if my shorty motor has been worked in some way before I got it. With my 45 it used to run like I thought a 2f was supposed to - a solid, torquey motor that will lug all day but will never be a quick truck. My shorty is a different kettle of fish. I must mention that it has a full fibreglass body so the power to weight ratio is much improved but there has to be more to it. It's like the motor has two operating modes - a normal one like my 45 used to run but when you give it a boot-full of gas it really goes hard when it gets over a certain number of revs (I would only be guessing what RPM I'm talkling about). It's not like it throws you back in your seat or anything but the increase in power is awesome compared to what my 45 had. It has a much higher top speed as well - when I first bought the shorty I wound it up to 140kph and it got there pretty quick too with more to give untill I backed off because the original stiff suspension start to bounce the rig around!!! My 45 was flat-out at 120kph (only a 4 speed I know) but it took an awful long time to get there and if my 5 speed is stock then the gear ratio's from 1 to 4 are the same.

So, with the power boost that I get my old man reckons it's just the second barrel of the carby opening up but my 45 never had a power increase like this.

Could it be the carby like my old man says or is it more likely that the motor was worked in some way when the truck was rebuilt for galvanised chassis and fibreglass body?

Any thoughts? and does the second barrel of the carb work like this and at what point does it kick in??

You're right - this is a good site, but nothing compared to the info & advice you'll get at: www.ih8mud.com
Go to the 40 series Landcruiser forum, & I'm sure you'll get plenty of good answers to any questions

Thanks Muddy, I've posted there too. Lets hope i get a bit more "lov'n" over there....lol. Maybe someone there knows a bit about 2f carbies.....

i imagine the shorty is a soft top with the fiberglass tub
you'de be saving heaps of weight there
other mods if any like wheels and tyres could have an effect but
I'd go and check to see if the secondarys are kicking in on the 45
if its stock it would surely need going over by know

hey mate sounds the same as my mota in the 50, soon as i got it goin i took her for a run gown the back... with a heep of tools and 3 blokes in it and soon as the second throat opened it had a "second win" and the powa increase was unreal! this in on a 4speed to no a 5speed! my mates 2wd hilux is the same to sum motas are more sesponsiev when the second throat opens, its sorta like the powa band on a 2 stroak

Hi Tyler

I also posted on the Ih8Mud forum and got a similar response from a guy who had just rebuilt his 2f carby. When the secondary kicked in the difference was really noticeable. Sounds like my 45's carby never worked right. And to think I drove that ute around for years with a shonky carby and just thought that that was the way it was supposed to be! I shouldn't speak ill of the old girl though - we had some good times and she never let me down and would chug through anything. I loved the sound of that rig when it chugged through its short side pipe! My shorty "screams" in comparison though with a "proper" carby and lighter weight so I won't make that mistake again, lol!

Thanks

Isn't it great when you find a fault you didn't know you had? In a good way... I've never felt the second throat kick in so had a look at the linkages - too much slack in the throttle cable so it wasn't turning the linkage far enough to let the the second throat open. Now how do I check it's working? With the throttle fully open, the second throat will turn by hand against a light spring, but with the engine running (no load of course) it doesn't open with a quick burst at full throttle. I guess it needs to be under load with a high airflow to open it? There seems to be a slight power increase on the road, and a slight change in the exhaust note, but definitely no "surge" of power. Then again, maybe it's just wishful thinking because I want to feel an improvement... I guess every little bit extra is nice, but I wonder if it's only opening part way. Anything else I should try?