F3 swap
#1
01-04-2020, 02:07 PM
F3 swap
Just picked up a complete f3 engine on frame. So I have looked though a few threads on the topic. My question is, since I will be using the carbs that came with the f3, I need to transplant the harness as well for tps. Would it be possible to just use the f2 harness and move over the f3 cdi and run new wires for the tps, fuel pump, etc? I only ask because the harness that came with the f3 looks a little butchered in a few spots.
Last edited by Igniuslacerta; 01-04-2020 at 04:19 PM.
#2
01-06-2020, 08:26 AM
It's been a while since I looked at something like this. So this is from old memory.
The F3 carbs will not clear the frame because of the tps sensor. F3 frame have a slight notch. F2 don't, so you'd have to cut/weld the F2 frame.
I'm also heard of people using really big hammers to fix this, but I would never recommend it.
The F3 carbs are different, they used a TPS. F3's also use a fuel pump and different CDI to compensate for the ram air system.
It all works together as a system and swapping parts of it don't work well.
IMHO, the ram air was a fustercluck. A lot of complexity with no real benefit.
The easiest way to go is use just the F3 engine block/head. It's almost identical to the F2 block.
Then just use carbs from the F2 and everything else from the F2. It avoids a lot of problems.
You will have to mount the shifter clamp upside down on the F3 as it has a reversed shift pattern.
Unless you like GP shift. You'll also have to cut the bodywork a bit to clear the shift rod/clamp.
The F3 carbs will not clear the frame because of the tps sensor. F3 frame have a slight notch. F2 don't, so you'd have to cut/weld the F2 frame.
I'm also heard of people using really big hammers to fix this, but I would never recommend it.
The F3 carbs are different, they used a TPS. F3's also use a fuel pump and different CDI to compensate for the ram air system.
It all works together as a system and swapping parts of it don't work well.
IMHO, the ram air was a fustercluck. A lot of complexity with no real benefit.
The easiest way to go is use just the F3 engine block/head. It's almost identical to the F2 block.
Then just use carbs from the F2 and everything else from the F2. It avoids a lot of problems.
You will have to mount the shifter clamp upside down on the F3 as it has a reversed shift pattern.
Unless you like GP shift. You'll also have to cut the bodywork a bit to clear the shift rod/clamp.
Last edited by Phil314; 01-06-2020 at 08:38 AM.
#3
01-06-2020, 03:30 PM
#4
01-06-2020, 04:46 PM
They are different, but I think the mounting points are the same, so it should bolt up or be close.
But the hoses are different. You will probably need a F3 lower hose.
On the F2 the upper hose connects directly to the radiator.
On the F3 the upper hose is similar/same, but connects into a fill T and down tube on the F3 radiator.
You'll need the fill T and down tube.
#5
01-06-2020, 04:49 PM
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