idleing over reving help

[tommyboyblitz]

i have a 2.5 engine, with a brand new carb. having major problems with idleing and running.

it idle's very high and i no matter what i do to the idle screw doesn't make a difference, also done the hsn every which way and no difference.

when i bought the carb the guy said not to touch the lsn so i haven't as i messed it up on my last carb. (i broke the hsn off of my last carb which seemed to be running fine, would get hot now and again though)

I've got standard exhaust and brand new fuel tank and pipes...

is my engine fiddlesticked or does it just need somethign else doing?

 

[olds97_lss]

Usually if your idle is high and adjusting it via the idle screw does not do any good, your lean on the LSN or you have a serious air leak somewhere.

I'd try richening the LSN a bit and see if it helps.

 

[tommyboyblitz]

i did try that but made no difference i ended up richening it about 1/4 a turn, where would i find an air leak?

duh... I'm so stupid haha

didn't put the carb on properly

my bad

 

[olds97_lss]

Around the carb neck and backplate. Get some high temp sensor safe RTV from an auto parts store. Then put a light coating of it around the neck of the carb prior to installing it. Make sure to press down hard on the carb before tightening the cinch bolt. PUt a coat of it around the perimeter of where the backplate makes contact with the crank case, then put the backplate back on. Let it cure for 24 hours prior to using.

I'd richen it more and see if it helps at all.

 

[cwal1774]

I agree with olds97 try this start the truck and listen to the idle if it's too high richen the lsn until the idle comes down then make some passes and listen to the truck as you come off the throttle if it hangs up or takes a few seconds to idle down then its still too lean it should idle down smoothly when you come off the throttle if you get it to do that then do a pinch test.

 

[tommyboyblitz]

hmm still having the same problem, i have no spur gear at the momentr as when i last ran it it stripped it when i revved high.

I've tightened the carb while pressing down on it, and it only made a small difference, also I've tried lowering the rpm and it wont stay at idle and just cuts off when i remove the glow starter.

i did notice bubbles coming from between the head and the block, and 3 of the hex screws had sheared , I've replaced the hex screws and the head is firmly bolted to the block with no gas excaping but still can't get the thing to idle at low rpm.

cheers for your help

 

[olds97_lss]

If you take off your head, do you still have at least one copper/aluminum shim in there between the head/head-button and top of the sleeve?

 

[510Maxx]

You know I've got the same problem on my Maxx, I recently rebuilt the whole thing and added a THS tuned pipe, bigger cooling head and rebuilt the carb. I completely sealed the engine and the carb with sealant so i know for sure that there is no leaks, however it idles high and the wheels keep moving and when i pinch the fuel line it dies in a second or less. My gap is set right...... do i have a lean LSN?

 

[Metalhead Matt]

Sure sounds like it. Try factory settings and lean 'er as needed.

 

[510Maxx]

last night before going to bed i richened it real quick with wheels of the floor and it did slow it down! i will be tuning it more today...... thanks guys