possible new 720

[njwett]

Hey guys Im looking at possibly picking up a 720 that needs some work for a steal. My brother called him today and says its a compression issue could be a valve or a head gasket. I know head gaskets are pretty common problems with these engines. If it is what are some definite signs I should see? I think either way I might pick it up. Hopefully its a head gasket and I can replace it myself. let me know what I should be looking for if its a blown head gasket.
thanks

[Swschz]

Cool as.....starting to make me want to get a damm 720 hahaha.

[njwett]

Hi guys. We ended up getting the truck for $350. with no compression in cylinder 3 and 4. I tore into got the head removed sure enough the head gasket was blown right inbetween the 3rd and 4th cylinder. got the head resurfaced cleaned and pressure checked threw it back together yesterday. my brother went to start it and the starter just spins, it doesn't engage with the flywheel. as far as we know the starter is good. the battery ground goes straight from the negative battery post to the engine block. I believe the battery negative post is supposed to be grounded to the chassis and the the block ground to the chassis also. could this be causing the starter issues. What else would cause the start to just spin and no engage the flywheel?

[$krap_IN_flesh]

needs a starter or just bang on it with a hammer to get it to engage

[njwett]

alright well the engine is cranking now but it wont fire. I realized today that is carburetor choke is stuck open. i will need to get that closed. But its not even trying to fire. what is weird is that I pulled the first spark plug and there wasnt any fuel on it but there is fuel spraying out of the carburetor when ever we try to crank it. I pulled the second spark plug and there was fuel on it. Why would there be fuel on the second spark plug and not the first. the timing is good and lined up. i have spark from the coils, but i havent checked each individual plug.

[njwett]

alright I got the truck running and it fires right up. but it idles extremely high at around 3000+ rpms I've check the vacuum lines dont really see any problems i will replace them anyways. when i put my hand over the choke the idle goes down and it stumbles. there is a lot of sucking coming from the choke it is closed. If the timing chain was a tooth off could it cause the engine to idle extremely high like this?

[njwett]

can anyone tell me how to adjust the throttle plates on a 720 hitachi caburetor. I've already turned the throttle plate adjusting screw all the way out but it still doesn't close the throttle plate all the way. I can look down the throttle body and see that the throttle plates are still stuck open causing the truck to idle at 3000 rpm. if anyone can give me some help that would be awesome.

[bendiesel]

your throttle cable isnt binding anywhere is it? just a thought! Not sure exactly whats going on. Got any pics of the issue at hand? possibly a pic of the adjustment screw and throttle body. a pic of the throttle plate. and anything else you may have done while taking the head off?

[njwett]

Ill try to get a pic if i go over there today. when my brother was turning the screw i was watching the plate close and it was closing but when the screw was all the way out the plate was still open a significant amount. the throttle cable isnt binding as far as i can see. I think we will just remove the caburetor to get a better look at everything.

[njwett]

alright now i am fairly certain it is a timing issue. If the cam gear was a tooth advanced would it cause lots of detonation and pinging and cause my truck to idle very high.

[napias720]

easy fix, while ur at it just get a engine rebuild kit from ebay about 128 bucks and it came w/everything gaskets piston rings etc. you might have to take you head to a machine shop and resuface ur head.

[bagndrag]

so where are the pics of this bad boy