Hitachi Jet Q

[atkinson40]

Old thread was getting kinda long and off original topic.

 

Found that I could screw the idle screw WTF out to get it running better.

 

Reading up,  I found this was a syptom of a vacumm leak. 

 

Squirted carb cleaner around the base screws and drat.  Engine change.  I have a leak.

 

Pulled carb and am going to cut a couple of new cork gaskets for above and below the phenolic spacer.

 

Pulled the jets below the bowl to check them and noticed they are different. 

 

One says 112 and one says 155.  The smaller one leads to the smaller throat and vise versa.

 

Is this correct?  Thanks kevin

[atkinson40]

Never Mind. :blush:

 

Google is my freind.

 

http://community.ratsun.net/topic/48198-stock-hitachi-running-rich/

[atkinson40]

Replaced the gaskets top and bottom of the phenolic spacer with 1/32 carton gasket material.  Still leaked.

 

Replaced the gaskets with cork material.  No leak, but idle screw still doesn't have much affect.  Idles like crap.

 

Removed idle screw and squirted cleaned in the hole and I can see it coming out the hole in the barrel.

 

Interwebs tell me no idle screw adjustment means vacumm leak. 

 

When I put my hand over the carb barrel and reduce the air intake, it seems to get better.

 

I can hear a pulsing,  cccsstst, ccsstst noise coming from down the barrel.  I assume this is the idle gas.

 

But shouldn't it be continuous? Not pulsing.  This seems to coorespond to the pulsing of the engine/idle.

 

Going to look for more leaks and see if the throttle plate is above the idle hole. 

 

I think it should be to create an idle vacumm to pull in gas at idle. 

 

Thanks kevin

[Rays74]

You get it solved Kevin?

[DanielC]

Make sure the secondary is closing all the way.

[atkinson40]

You get it solved Kevin?

 

Thanks Ray, Not yet.

 

I'm still fighting why I can pull the #3 plug wire while it's idleing an get no change in the motor.

 

I thought it was carb, (and it still may be) but I picked up a hitachi and swapped it.

 

No change in the problem.

 

I'm going to do a comp test.  Only thing I haven't changed out is the head.

 

I had that rebuilt by a good shop.

 

Thanks Kevin

[atkinson40]

Make sure the secondary is closing all the way.

Thanks DC, Will do.  Kevin

[atkinson40]

Did a comp test 1-4, Dry 130, 150, 150, 150.

 

Drat you #1 cylinder.  :mad:  Dunno what's wrong there.

 

This engine only has about 10 miles on it since R&R rings and rod bearings.

 

Maybe #1 ain't seated yet? 

 

Used el cheapo, push in the hole, rubber, comp tester also. 

 

I know its not perfect, but it worked as a diagnostic tool.

 

What these readings show me is that it's not mechanical.(rings/valves/timing) 

 

If it  was #3 would be the lowest comp, not #1.

 

#1 cylinder has the most affect when I pull the plug wire at idle,  #3 has none.  WTF.

 

Took a picture of the plugs,  Interwebs say they are OK looking.

 

 

When I spray anywhere around the carb body with starter fluid, The idle goes up. WTF.

 

Shouldn't it be reverse? 

 

Is the vapor from the fluid going down the throat and making the idle go up? 

 

Still looking for a weber.  The one from CL I picked up is missing linkage and choke plate.

 

 

I swapped out the Hitachi with another I picked up with the weber, but I'm beginning to supsect it leaking also.

 

Can I change my name to junkyard dog?  I'm spending so much time there my wife thinks I have a GF there. :w00t:

 

Thanks Kevin