Rebuilding my Hitachi tomorrow

Silverbullet · Post by **Silverbullet** » Thu Apr 21, 2011 10:32 pm

Hopefully!

Gettin up bright and early to sort out the shed, get the bench setup and completely free of everything, put a big rag down and then set to work on the car. Got the carby kit and can of cleaner ready, studied the diagram and instructions head to toe.

Just wanted to ask who's rebuilt one before? What should I watch out for specifically? and the big one; what if I have the wrong carb rebuild kit?

I say that because the cars engine was changed in it's lifetime (from 81' to 82' touring wagon engine) and we're not sure if they changed the whole engine+carb over, or just the block and put the old carb on it. In either case the carb does NOT have an ID number stamped on it

Me and dad discussed it for ages and we ended up getting the 81' kit. How much difference can there be between the two? Being Hitachi's, I'm guessing ALOT of difference. Can the carb be put back together in working condition if I have the wrong kit?

That's enough for now, any help on this would be very much appreciated, since I'm flying by the seat of my pants on this one

Cheers

P.S to FROG, I might end up asking for an 82' kit express posted next week

steptoe · Post by **steptoe** » Fri Apr 22, 2011 1:38 am

take photos for reassembly, from all angles, prior to dismantle. Many kits have more than required bits in order to cover more than one model or even manufacturer. Hope it all goes OK on a day most parts places will be shut!

Venom · Post by **Venom** » Fri Apr 22, 2011 8:52 am

Check to see if the gasket for the top of the carb (to access bowl etc) is correct, that's what i found to be different between kits. I'm not sure what rebuild kit you've got, but a lot of them don't actually have all the parts you need for a full rebuild.

If you've got the wrong kit then look up carburettor specialists in the yellow pages, I found half a dozen around Melbourne and each had every possible kit in stock. Take your carb in and make sure you get the right one. Hopefully you've got the right kit though.

Good luck with it!

Silverbullet · Post by **Silverbullet** » Fri Apr 22, 2011 11:43 am

Well I've started, got the carb off. It went better than expected, the 4 nuts holding it to the manifold came undone without complaint. I put the carb on the bench and went back to the car to get the old gasket off and, well, see photos

My heart sank to my toes when I saw this

The new gaskets are wrong apparently. But then I saw that the old gasket was wrong as well! around the coolant hole you can see the outline of the old gasket, and the square to round gap has been filled with sealer

Is this an acceptable solution to the problem? this could also show that the carb has been swapped over, and whoever put it back on didn't have the right gasket either.

I forgot to mention I need the car working again on wednesday

Post by **TOONGA** » Fri Apr 22, 2011 12:48 pm

thats the same as the gasket that comes with the kit from subaru. it is a generic fit as the hole size on manifolds differs between countries and models.

it looks exactly the same as the gasket in the aftermarket kit I have for a carby off a 89 brumby.

if you are really worried a small dab of silicon around the edge of the gasket will stop the problem. (just be careful that you dont use too much as it will block the pipe)

TOONGA

Silverbullet · Post by **Silverbullet** » Fri Apr 22, 2011 1:32 pm

Ok, thanks toonga! Looks like that coolant hole doesn't do anything anyway, it's a dead end inside the carb

I continued with the disassembly, took my photos, wrote notes and labels for all the jets and put them in separate compartments in a plastic tray. Everything was going so well (too well infact)
I'm down to the last few steps, taking the throttle chamber off of the float bowl chamber, and I can tell that someone has taken this thing apart before; There are 3 screws holding the two together. The first two came out fine no problems. The last screw (as it always is) is seized, completely and utterly. And to boot, the last person to do this has gouged out the screw head so no screwdriver will get enough grip to turn it

:evil:

I'm so close, the last screw

I'm completely stumped as to what to do next...any suggestions? and of course it's the screw where access is blocked so the driver doesn't sit flat in the screw anyway...

steptoe · Post by **steptoe** » Fri Apr 22, 2011 5:53 pm

put the other two back in and tighten to acceptable tightness - often releases tension on th bugger with stripped head. Make new flat blade slot with basic tools, soak overnight in CRC 556 etc, call a friend....

Post by **TOONGA** » Fri Apr 22, 2011 6:50 pm

yep I agree put the other screws back in and try to lossen off the one that won't budge.

another way to try is to put the carby in a vice (protected of course) and try to use a pointed drift or chisel to slowly tap the offending screw loose

TOONGA

last celtic warrior · Post by **last celtic warrior** » Fri Apr 22, 2011 8:06 pm

The little pipe the the base of the carby is there to stop the main venturi icing up at low throttle position, and the car will run like crap and use extra fuel if it's blocked up...

Silverbullet · Post by **Silverbullet** » Fri Apr 22, 2011 8:23 pm

I got the screw out! did a combo of those suggestions, thanks. But ended up cutting the head off, removing the float chamber and twisting the remaining stud with vice grips to unscrew it. Usual suspect, white powder from the aluminium was on the end of the screw. Found a bolt with the same thread to replace the old screw.

After that, I finished taking it apart, cleaned it and put it back together! all in one day everything went better than expected. I managed to get it back on the car and all connected up as well. Here's where the troubles start

First startup: absolutely perfect, sounded like I've never heard it run before, smooth, quiet and no misfires to speak of. 5 seconds in, engine starts revving up and then loud (I mean LOUD) popping/knocking sound coming from the engine, even louder at tailpipe. Engine continued to rev till I shut it off.

2nd start: fuel sprayed out the top of carb, engine started and same popping/knocking sound, shut off after a few seconds.

All starts after that: no more fuel spray, but still same noise and engine revs up gradually. Pushing accelerator makes the noise louder (duh

) Also venturi at the front of the carb (primary?) is wet with fuel. Exhaust does not smell of fuel.

I have no idea what's making the noise but some things that could have gone wrong during rebuild:
- Primary and secondary jets could be swapped (they both fell out together and I didn't know which was which for sure)
- Float level was altered because according to the book it was about 15mm out

but the level on the sight glass is almost perfect, -/+ 1mm over the dot in the middle
- Idle mixture screw could be completely off; the mix screw before was completely missing a washer and O-ring, and was turned right down to the seat and car was still running rich. Because of this I had no rough guide of where to return the screw to (number of turns)
- Something about the choke position doesn't seem right, and the car starts up and revs up on its own with zero choke input even from stone cold

- When I pulled the carb off to begin with a little bit of coolant went into the manifold and slipped down to drivers side cylinders

Whatever the case, looks like I'm taking the carb off again

At the moment I'm leaning towards jets being swapped since one of the venturis is glistening with fuel, but would it really make that noise and rev up the engine? I also pulled the plugs on the drivers side, they were bone dry but carbon fouled from before the rebuild. If you ignore the noise, the engine seem to sound ok, but it's hard to ignore the noise

vid:
http://www.youtube.com/watch?v=rNA79m2-5WA

Post by **TOONGA** » Fri Apr 22, 2011 8:48 pm

I have heard a noise like that once before and it was a washer embedded in the top of a piston smashing into the head.

did you lose anything in the removal process?

TOONGA

Silverbullet · Post by **Silverbullet** » Fri Apr 22, 2011 10:34 pm

Oh man don't say stuff like that

Got me worried haha. The only thing I could have possibly dropped down there is some tiny fragments of gasket, I got a rag in the hole pretty quick after I took the carb off, and didn't find any washers or anything missing when I put it back together...If it was something like that what would it mean, take the heads off?

steptoe · Post by **steptoe** » Sat Apr 23, 2011 10:09 am

the knocking noise sounds like the Dieseling effect of timing out or something? Too much advance. At least you know it ran sweet first up - you did something right - the idle circuit is good then!!

Revs go up with more air getting past throttle blade or like a 2 stroke mower running out of fuel, runs lean then revs go up before cuts out ??????

Did you keep kids and mates out of the way No alcohol until after ? I recall when Hughseybabes mate dropped the washer causing a valve to stick open - ended up buying a true twin port twin carb EA81 and going whole hog rebuild and was really happy- in the end

steptoe · Post by **steptoe** » Sat Apr 23, 2011 10:15 am

Ohh, just played the video ........
firing order is 1342 on most normal fours, these flats are not normal, you say plugs out, leads run 1324 firing order ?

Silverbullet · Post by **Silverbullet** » Sat Apr 23, 2011 10:35 am

Yeah I'd never heard it run so good...until that noise kicked in. Can't wait to get the noise sorted.

Ok so, dieseling or out of timing could be possible, would the vac advance on the dizzy have something to do with it? I can't really adjust that without the engine running so that could be tricky.
Running lean is another possibility, like I said I had nowhere to go back to with the mixture screw since it was seated before I started, also the idle speed screw could be wrong as well since it hasn't moved since the rebuild (so still set for the rich running carb)
And yeah I did the whole thing by myself, didn't let dad touch it when he got back from work (last time he touched it when I was doing something he wrecked the lead going to coil by forcing it on and bending the insides

)
And you just reminded me of firing order, I took two leads off the dizzy to get better access to the carb mounting nuts, I'm pretty sure I put them back right but I'll double check. I wouldn't have thought the engine would run at all with two leads swapped though?

The video doesn't really show it properly, but the noise isn't so much of a knocking or banging, more of a popping and sucking...it's a bit hard to explain

Cheers steptoe once again

Now I've got plenty to check over I'll write a list and get out there.

Silverbullet · Post by **Silverbullet** » Sat Apr 23, 2011 2:23 pm

What can I say

:oops::oops:
I feel like an idiot. You were right TOONGA, I left something behind. I don't know how it happened, I took the rag out, I even have it on the bench to prove it! It doesn't matter now though, it's out, and I'm praying that nothing is bent

The noise was because the intake valve clearance got knocked way out. We managed to get the thing out through the spark plug hole carefully.
Let this be a lesson, to me especially

Cylinder #3 spark plug hole

Intake clearance knocked totally out

The culprit after pulling it out

Post by **TOONGA** » Sat Apr 23, 2011 3:04 pm

LOL my wife just asked my why I was laughing so hard (sorry)

those EA81 motors are almost indestructable Im pretty sure it will start and run without problems (heres hoping)

Im just glad it was soft and not washer as I suspected

did you have a rag in the bottom of the carby to keep dirt out, or 2 rags in the manifold?

still smiling

TOONGA

Venom · Post by **Venom** » Sat Apr 23, 2011 5:37 pm

Hahahahaha. i did exactly the same thing when i did my weber conversion. Had a rag in manifold to stop a nut or washer from dropping in, test fitted the carburettor and must've forgotten about the rag. It got stuck halfway in the manifold on the drivers side. Ran like shit on two cylinders, took me 3 days to work out where the rag was.

steptoe · Post by **steptoe** » Sat Apr 23, 2011 6:07 pm

Shhh, fellas, no one has ever done this before in the entire automotive fiddling history....Venom is just telling fibs to make you feel better.....

Naw....actually...it has been done before, but not to that extent, Jesus (it's Easter!) look at that rag! looks like it was a flame retardant as well ! Nothing bent in the rocker gear, cannot exactly see from your pics.

Wait until you advance to turbos and leave a rag (same colour as stuffed in the other end)on the turbo intake, snuffle the boost or what! Or the painters rag stuffed into the fuel tank filler tube that somehow falls in, stays there for years until one day it blocks fuel pick up just nicely

Nearly piddled self laughing as you admitted fault, bet yer dad is too !! Nice work !!

Silverbullet · Post by **Silverbullet** » Sat Apr 23, 2011 7:47 pm

lol thanks guys, makes me feel a bit better about it

And it's just one thing after another over here, one of the threads in the block for the manifold bolts is stripped out (it was before I got to it)

And of course, as I was testing the theory that it was stripped by putting the bolt in without manifold on, the bolt came out out, and the spring washer jumped off of nearly 4 inches of bolt and jumped straight down the hole into #4 cylinder...it's just not my day

I was even saying to dad about the rag, it could have been worse...well, now it is.

This has nothing to do with the carb anymore, and one way or another this car is determined to have it's heads off