1985 Aero 80 (Rare 1 year made) Quit Running

[playingwithmud]

What it did
So I was driving my Aero and it has run great for 2 years now after a full restore and I just quit running on me. I was on my way to the beach and was about 20 minutes into a drive doing about 40 mph and it just shuts off. I pull off the side of the road and it started right back up so I kept going thinking it was air in the gas line or something dumb. About 20 seconds later it back fires and shuts off again and now it wont start. Had to trailer it home.

What it dose now
Cranking with out any throttle and it cranks as if no compression.
Cranking with full throttle and it loads up like its firing against the starter but never actually fires the cylinder.
Cranking with 7/8 throttle and it will backfire out the exhaust.
Spark looks good

What I tried
Spark plug was oil soaked so I cleaned it off a few times and tried starting with same results as before.
Sprayed starting fluid just to see in both the intake and down the spark plug hole with same results as without
Put finger over spark plug hole and cranked and seemed to have good compression.
Pulled the oil injection hose off and oil looked good and was not stuck wide open.

What I think it is
I think when it back fired the second time and died well riding it the key way striped. Had this happen on my Aero 50 a long time ago.
Problem im having is I cant get the fly wheel off to check it. I tried to pry on the fly wheel well tapping the crank shaft and that did nothing. So I built a puller and its just bending it. Thought about reinforcing the puller but figured I would see what you guys think. Are they suppose to come off that hard or is the striped key way maybe stopping it? Or is this not the posible problem with it running at all.

Thanks for any help. I want to get this thing going again as its been 85 deg or hotter out all week.

[motormike]

The NH 80 Aero was sold in the USA for 3 years.
1983, 1984, & 1985...

[playingwithmud]

This helps me in no way, shape, or form but I have to admit you are right they made the NH80's for 3 years. However if you take the time and know your Aero's you would know that the 1985 is nothing like the 1983 or 1984. I own a 1984 and a 1985 Aero 80 and if you like I could take a side by side picture of them and you will understand that there is nothing other than the motors that are the same. And that can be disputed as well since the 1985 has no kick start, a different exhaust on it, and different rims. There are no interchangeable body parts between he 2 of them and the 84 has a top speed of 40 were my 85 can do about 44 leaving me to believe there are even more than the above listed engine differences. I have added a picture of my 84 (red) and 85 (copper) at the bottom.

And update for this is I went out and bought some longer bolts (M6 x 1.0) to fit into the plate and a bought a universal puller. Hopefully this will work and I will update with progress. I did forget to mention though that the part im trying to pull off has internal treads like its supposed to be pulled with them and not the cooling fan mount bolts.

[Dr_Craw]

i as well have a 85, with a similar problem. turns out the reed valve was partially busted.
I'm using this kit to replace the carb and intake (mine takes the standard dio intake)
http://www.ebay.com/itm/HONDA-Dio-ZX-Jo ... 1205770910

to pull the flywheel you usually use one of these.
http://www.ebay.com/itm/27mm-24mm-Magne ... 2199009644

[playingwithmud]

Thanks for the links. I think im going to buy the fly wheel puller and wait till that comes in before trying to pull the flywheel. Im afraid im going to just pull the threads out of the cooling fan mount. Ill take a look at the reed valve well im waiting for the tool to arrive. Thanks a bunch for the help I really appreciate it!

[Dr_Craw]

make sure to check the actual size of that threaded area on the flywheel to make sure you order the right puller. i just posted one as an example

[playingwithmud]

Can do. Was your 85 a Aero 50 or 80? If it was a 80 did the http://www.ebay.com/itm/HONDA-Dio-ZX-Jo ... 1205770910 kit do anything noticeable as far as top speed and acceleration and what else was needed to make it work?

[Dr_Craw]

a 1985 aero 80, yes. I haven't finished with it yet - i scavenged the rubber boot between the carb and intake for another more important project, so im waiting for a replacement atm.

[patthesoundguy]

If the reeds are toast you can have a wet plug and rich symtoms. If the reeds are toast hi ust get a set of boyesen 740 reeds and life will go on. If the flywheel key is sheared you should be able to see with the flywheel nut off. Try a new spark plug if you haven't already. I have had bad plugs on many occasions. Cleaning a bad plug won't help. Some plugs fail and will spark when not installed, but once installed no fire. New plug and off it went

[Dr_Craw]

btw this is how my reeds looked

[MrJumps]

"Reeds are tasty" said the little honda that probably could and a little more

Sounds like you may have poped a crank seal out see if the one under your variator is popped out or it has a hole in it.

[theycallmevrod]

Hey Drew_Crew, did you get a chance to install the HONDA Dio ZX Joker Elite AF16/18/27 DD50 DJ - Intake PWK 24mm Carburetor Jet Kit? I also hAve an 85 Aero 80 and would love to get more MPH. Mine tops out at 40-43 MPH. I've been trying all summer to get more out of the old girl but no luck.

[patthesoundguy]

You should get a bunch more top end with the carb setup. The flow on the aero 80 is very conservative. I've had mine up to near 55 on a downhill and it's pretty apparent that some better flow will get some more revs. There is an article where someone used a 24mm carb and got lots more get up and go. Even a 19mm dellorto carb would wake the thing up I'm willing to bet. If I haddnt been so crazy busy the last few years I would have already tried a better carb on my aero 80. I think the Polini cp carb would be amazing on it. And I would like to send an aero 80 cylinder off to the porting ninja and see what kind of magic is hidden beneath the conservative daily commuter shell.

[playingwithmud]

So I spent some time on it today and went right after the reed valve as I have not ordered the tool to pull the crank pulley off yet. Everything looks to be fine other than one of the reeds sits just off the plastic but when pushed on sat right into place. I took it apart and everything looked great. Put it back together and still did the same thing as before . I then went out and got a compression tester and checked the compression. To my surprise it was only 60psi.

So my question is what would make my Aero go from perfectly running for the last 2 years to having low compression? This thing was running perfectly when it shut off on me and was my 20th some trip to the lake this year. I sprayed oil down the spark plug hole and cranked it over again and still only 60psi so im guessing its not rings.

Thanks for all the support im getting from this page. I hope I dont need to get a whole new engine for it as I already spent so much on getting the body restored and painted.

[playingwithmud]

"Reeds are tasty" said the little honda that probably could and a little more

Sounds like you may have poped a crank seal out see if the one under your variator is popped out or it has a hole in it.

Could this cause low compression as well? If so I think I know what my next move is.