Hi guys, have a 1980 ke55 and I just took the motor out and replaced it with one from a ke70 while using the ke55 cam, carb, distributor, head etc.

Has new coil, points, condenser, cap, rotor, leads, seals, headgasket etc.

Timing set to 8degrees btdc, points set to 0.4mm, valve clearances set cold.

Starts fairly easily and can rev in neutral easily like it used to but if i give the accelerator a few jabs it dies until it returns to idle, also when I take it for a test drive it doesn't want to rev easily and dies when I go over around 3000rpm.

Just wondering if you guys can give me some tips or what your thoughts are on the problem and how to fix it?

First time posting on here so hope this is the right section, thanks.

Sounds like carb. Too lean for some reason, an air leak or an open vac line or a blocked pump jet. Does it run better if you pull the choke out?

 

The ignition side of it looks OK.

How is the carb? It sounds like a maladjusted or inoperative accelerator pump circuit leaning the engine out.

If I pull the choke out it sputters a bit and is slower to accelerate, still has the same problem when driving.

It is the carb from the old motor that was running fine, I have changed the aircleaner though from one the size of my fist that was really dirty to a larger clean one

.4mm gap for the points seems to me not right...........

Edited September 11, 201511 yr by Clapped out

Did you take the inlet or exhaust manifolds off?? Check the nuts being up tight?

 

Still sounds like carb... how about fuel pump not delivering anough to keep the float level up. Fuel pump not working on the cam correctly, that insulating spacer is important.

 

Can you take it for a run and when it dies switch it off immediately, then take the carb top off and check how high the fuel is?? Not a very definative test, but if it is low or too high its a clue.

 

Another option would be to ride it in the dying spot then turn it off and pull all 4 plugs on the roadside. See if they show signs of over-rich or lean.

 

I'm planning exactly the same for my two KE70s in a week, head and everything off one onto the block in the other.... this is not sounding good!

 

0.4mm is 16thou, about right isn't it Clapped Out?.

Yeah manifolds have been off but have done them up and sprayed "start ya bastard" around manifold and seems to be no leaks there.

 

Fuel pump is a ke70 one with the spacer it came with out of a running car, previously checked fuel bowel level and it was fine after running.

 

Will go and check plugs after dying now.

 

 

Might see if I can find another known working carb to try on it.

Edited September 12, 201511 yr by luca

Alright so fuel was coming out the top of the carb when I pump the throttle without the engine on so I replaced the top portion of the carb (needle and seat, accel pump, float etc)

 

Runs better down low now but still has the problem once you drive it over a certain amount of revs.

 

spark plugs show signs of carbon fouling

spark plugs show signs of carbon fouling

Ah! Thats good! Now we know what the problem is, and you only have to find out where it lies. So its not leaning out from a leak, its flooding from somewhere.

 

Usual culprit would be the needle and seat of course. How's the fuel filter, and any shit in the bottom of the carb bowl?? Nothing worse than some degraded plastic fibre or silicon getting through a broken filter and under the pump valves so it has no fuel pressure and runs lean, and then under the needle seat and it floods and runs rich.

 

Other options are hard to find- too much pump pressure..? Unlikely I expect. Wrong jets in the carb?? Also unlikely, but maybe someone was fiddling with it...

 

Is there a difference in the plug colour after idling/running at 2000rpm in neutral for a couple of minutes, and the plugs when its dying under drive on the road?? I just wondered where it is rich, low down, under load, or both???

Hey guys, ended up resetting cam timing and played around with ignition timing etc. Got it running a fair bit better but not as good as it was before I changed the motor.

 

Then swapped it for a ae86. Thankyou to those that gave me their input/ideas in this thread!

You swapped a ke55 for an ae86? You must not live in Aussie.

Haha, ke55 was going with rego, ae86 has no rego, bent front rad support and isnt going although it does have reasonable suspension (tein coilovers etc.)