# Honda EX1000 Revving too high after Carb rebuild - how and where to make adjustments?



## cobrajockey (Jul 4, 2020)

I've got an early EX1000, ~1986. Just rebuilt the carburetor, complete clean up after sitting (w/ gas for some 20 years) and wouldn't start - caramelized gas in main jet, passages.

I'm sure that some of the adjustment screws moved in the process of the rebuilt and cleaning, it started on the 2nd pull on choke, could quickly move to choke off and it stays running, BUT it's reving WAY too high. (I do get the generator green indicator light on the front panel, so that's OK).

While I've worked on motorcycles since a kid, I thought this would be easy, but I'll be damned if I can't get the RPM's to drop to what I remember (+20 years ago) proper range. I have the downloaded 45 page Owners Manual, but there is nothing in it about the carb, no diagrams, what needle adjustment is what or how to adj the carb for RPM (or the Governor either for that matter).

Below is my still pretty new looking 86 EX1000 and the only correct carb diagram I could find on the Net.

Anyone out there familiar with the carbs on the EX1000's and how to adjust what and where? Help!


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## iowagold (Jan 22, 2020)

#10 is low idle speed
use your finger to hold the throttle arm against the screw and adjust for the min rpm.
# 5 is idle mixture (2 turns out to start)
did you get the rod in the right throttle arm hole?
there are 2 of them.
the gov sets the run speed.
the service manual is what you need for the exact specs.


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## iowagold (Jan 22, 2020)

try this set of you tube links 
click here for the honda ex1000 videos on you tube


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## cobrajockey (Jul 4, 2020)

iowagold said:


> #10 is low idle speed
> use your finger to hold the throttle arm against the screw and adjust for the min rpm.
> # 5 is idle mixture (2 turns out to start)
> did you get the rod in the right throttle arm hole?
> ...


THANKS! This is great information to get me moving in the right direction to setting the idle speed and mixture. I think though I've somehow reassembled the Governor assembly incorrectly because it is not allowing the throttle butterfly to close down and I think that is why the engine is running wide open (full RPM). I'm going stare and analyze a bit and diddle with that a bit more. One thing I'm learning is generators are nothing like cycles I've worked on and restored all my life. If I can't figure it out, a friend of a friend runs a Lawnmower / Weed wacker / Tractor / Generator Shop and it's a Honda Auth dealer too. He said he'd look at it and fix what I can't with the Governor for $50., also adjust the idle and mix if I can't get it perfect. Seems reasonable.

I've actually searched for a hard copy of the Honda Service Manual online and can't find any in the US. There are a couple in the UK, but the shipping is ridiculous. Honda's website shows none available.

Watch all those video's before over the last few weeks in prep for tackling the rebuild. So are quite good, one young guy who looks like in his late teens has a fantastic one on a clean up and another guy, looks Hispanic has a great formal Carb rebuild vid on the EX1000. But no one seems to cover Mix and Idle speed adjustment or Governor Arm assem or adjustment. But many of them are hysterically terrible, guys doing a repair video having never seen a EX1000 before, no manual and not even the right tools to do the job. One guy with a "speed shop" has a repair how-to video where he's basically "experimenting" as he goes along and clearly doesn't know what he's doing. YouTube can be dangerous!


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## cobrajockey (Jul 4, 2020)

iowagold said:


> #10 is low idle speed
> use your finger to hold the throttle arm against the screw and adjust for the min rpm.
> # 5 is idle mixture (2 turns out to start)
> did you get the rod in the right throttle arm hole?
> ...


Wanted to thank you again for the advice, the '86 EX1000 is running now like factory fresh. 

I indeed somehow managed to re-install the Governor arm linkage incorrectly, but the Honda gen mechanic I was clued to found my two-left thumbs mistake. That was making the engine race near full throttle. After that I said I want to "tune" it myself and I used your advice above.

Turns out the mixture is spot on at 2-3/4 turns out, from all the way in. (I kept checking the spark plug for fouling just as I do tuning vintage carburated motorcycle.

Low speed idle was at 2-1/2 turns and it hums nicely even under load from a old school HD 110v impact driver or a 90-degree grinder. The frequency meter stay at 60hz even under load and output 127vDC no load.

The Honda dealer mechanic wanted me to sell it to him, he said he sold one in "very used" looking condition for $475 just a month ago. I only paid $500 new for mine in 86! I'm keeping mine, it still looks brand new.


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## Jon (Dec 2, 2020)

I bought a used EX1000 last year. The serial # id's it as one of the earlier batches. The unit is very clean for its age. I start it every month to keep it running, but over the summer it started surging and wouldn't settle down. I brought it to my mechanic friend. He specializes in cars and trucks but can figure anything out and is a guy I trust. He took the carburetor apart and cleaned all the buildup, then changed the oil and cleaned the air filter. Got it home it seemed OK. But last month when I started it, it raced as soon as I opened the choke. I mean insane RPM like 10,000. I thought metal bits were going to fly. After 30 seconds it settled down to normal. I had alot of other stuff going on and forgot about it until Dec 1 when I started it again. This time I shut it right down and started PM Cobrajockey after reading this Thread. I just got back from the same mechanic. He took off the air filter and cover and poked at the idler arm and said "something's gummed up" Spritzed the spindle that runs the butterfly with carb cleaner. Voila. Fixed. Apparently after cleaning the air filter he reoiled it according to the manual suggestion. He surmises some extra oil got sucked into the carb and gummed up after a month or so. Happy for the easy fix. Something to watch. Unit is running great again and I lowered the idle even more to get to 120V output.


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## tabora (Sep 6, 2018)

Jon said:


> He surmises some extra oil got sucked into the carb and gummed up after a month or so.


I had the same thing happen with a PowerMate PM1500. I'm in the habit now of checking the throttle and governor for freedom of movement after an engine sits for a long time.


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