Engine Trubble

[Prime79fj]

Hey guys<
i have a problem with my 2f, the Engine runs great and it has fast acceleration exspecually turning my 40 tall tires, the only problem is that the engine acts like it has a rev limitor, the engine wont run past 2 thousand rpm, the engine sounds like it is but according to the tach... its not and the tach is new. i have changed all spark wires and plugs, also changed the rotor and the cap in the dizzy. the dizzy had some rust in it but that shouldnt have a play in iti cleand the pick up real good. im thinking it mught be ingition???? im not sure input would be helpful thanks

 

[Poser]

i have a problem with my 2f, the Engine runs great and it has fast acceleration exspecually turning my 40 tall tires...

What carburetor do you have on your hot rod 2F?

 

[ocdbeetle]

In Neutral...not driving...will it rev over 2k? How about the 4-6-8 switch....Is it on 6?

 

[Prime79fj]

I have a stock dizzy that looks original with the 2f, an in Neutral it will rev about 2,300 but thats the max in all gears i still can get to about 60 mph driving i just cant get top end power. im not sure what you mean by the 4-6-8 switch could you explain

 

[ocdbeetle]

Tachs that are made for 4,6,and 8 cylinder engines have a switch on them that you can select so that the reading is correct with engine....

 

[ocdbeetle]

of course that wouldnt help top end power unless its a magic switch...lol

 

[Prime79fj]

im not sure if the tach has a switch but ill look.

 

[Poser]

What carburetor do you have on your hot rod 2f?

 

[Texx]

so, if you're going up through the gears, even first won't rev above 2300? Even when it sounds like it's wrapped up? Probably the tach. Hitting an indicated 60 with 40 inch tires would be WAAAAAY above 60. I don't have a calculator, you can figure that out, but I'd estimate far above 70 actual.

 

[Liam]

is it on a treadmill??

 

[Prime79fj]

i have a stock asain carb that has been rebuilt by a local carb shop, i i remeber when i had 35 tall tires the engine wouldnt go above 3k if i remember, and not it wont got past 2300 with the 40 and yes even first wont go past 2300 when the tack hits that point it sounds like a rev limit and the engine start to sound like it back fires like it cant go anymore

 

[ocdbeetle]

Timing set right?

 

[Prime79fj]

the timing is just slightly advanced

 

[FF LC FREAK]

Is your pedal hitting the floor when you max out your RPMs? Or, do you still have pedal left without being able to increase your RPMs? My point is, your throttle linkage could be messed up.

 

[Texx]

Is it missing at idle, or running smoothly? Any miss up to 2000? Are you setting the timing with a light? You might try setting the timing to the highest idle by turning the distributor counter clockwise. It should be able to almost hit the oil filter. I'm wondering if you're a tooth off on the dizzy? Also, if you're getting your positive power for the tach from the coil, that's a problem.

 

[Prime79fj]

its not missing at idle it has a very smooth idle the tac reads 500 rpm for some reason it will idle at 700 but it is very smooth, it sounds smooth up to 2k its like the engine want to go higher but it wont let it makes poping noise like a rev limitor would make, but when i listen to it by ear it sounds higher then 2k but who knows. my tach has its own power source going to battery, there is a wire that connect from coil to tach, then theres a ground

 

[pb4ugo]

of course that wouldnt help top end power unless its a magic switch...lol

No magic switch. He could have the tach set on 8cyl & actually be reving the 6cyl to 3000rpm when the tach only shows 2300rpm. He did say he thinks the engine is reving more than what the tach says.
6cyl x 3000rpm=18000 sparks
8cyl x 2300rpm=18400 sparks
If that's the way tachs measure rpms.

 

[Trollhole]

Secondary not opening up?

Did I read this right? You have 40" tires?

What year motor and carb?

Post a pic of the carb and linkage.

I'm betting it's the secondary not opening.

 

[FF LC FREAK]

Just throwing this out there...

When I first got my cruiser, it had an old Delco dizzy in it that was wore out. It did the same thing you are describing. It popped and sputtered at about 2300-2500 RPMs (even with a new cap and rotor). I was advised by my Mud bretheren to get rid of the Delco. I bought a vacuum advance Dizzy from another Mud member and my problems went away.

Just something to consider. You mentioned that you thought it might be ignition. This would be in line with what you are thinking.

Good luck!

 

[badass]

guys i've seen and driven this truck it's got 4.88 gears, and does not have fast acceleration by any means.

Stock aisin, dizzy, and all ignition components...

It has NO TOP end. Will not rev past 2300 rpms. And no he's not dumb, the issue is not with the dam switch on the back of the tach for different cylinder settings.

It just starts to backfire and pop when it hits 2300.

I took the dizzy cap off and cleaned the pickup and starwheel. Engine runs very smooth at idle and lower rpms. Almost feels too lean. I'll have him pull the plugs and see what they look like.

I also have a feeling the secondary on the carb is not opening, like i said feels lean .