Harley X90 Air/Fuel mixture Screw Washer Question...

MiniMotoJon

MiniMotoJon

New Member
#1
#1
I am a proud new owner of a 1974 Harley Davidson X90.. After cleaning the carb I can get it to run with the Choke pulled up but it dies as soon as soon as I close the choke.

The mixture screw does not have a little rubber O ring and small washer on the end... I know not all carbs do but the 40 and 50cc Del Orto Minimoto Carbs I am familiar with do have them. I tried to fit a set from one of them and they do not fit..

My question is... Does the X90 Del Orto Carb require the O ring and washer on this screw or is it bare stock??

Thanks for any advice or help and thanks for being here! AFScrew.jpg SFScrew2.jpg

N!pples
 
MiniMotoJon

MiniMotoJon

New Member
#2
#2
A little more history... I have removed the tank for sealing and repair so Im running clean gasoline through a temporary tank.. I did clean the Carb with torch tip cleaners/Carb Cleaner and Air pressure.. A rebuild kit did come today but it did not come with that O ring and Washer I inquire about... I did a New Old Stock HD #7 spark plug, Original Oil in the injector tank and gearbox... Any one have Ideas on replacement gearbox and injector oil... I use Amsoil and Or Motorex in my other bikes... Workable?
 
x-90 rider

x-90 rider

#4
#4
MiniMotoJon said:
A little more history... I have removed the tank for sealing and repair so Im running clean gasoline through a temporary tank.. I did clean the Carb with torch tip cleaners/Carb Cleaner and Air pressure.. A rebuild kit did come today but it did not come with that O ring and Washer I inquire about... I did a New Old Stock HD #7 spark plug, Original Oil in the injector tank and gearbox... Any one have Ideas on replacement gearbox and injector oil... I use Amsoil and Or Motorex in my other bikes... Workable?
Click to expand...
There is no o-ring or washer required for the carb screw. I run Blue Marble oil in the injector tank. The manual calls for 2-stroke oil in the gearbox but I have better luck with SAE 30 oil.
The carbs are really finicky. Verify that it is clean. The other common problem is that the float sticks in the up and also in the down position. Sometimes it helps to bounce the rear wheel up and down a couple of times to jar the float loose.
 
P

PAP

Member
#6
#6
You might want to check the banjo fitting. I had one that somehow got a cracked bolt, and sucked air. Drove me nuts before I found it. Luckily I found it before it did any damage.
 
MiniMotoJon

MiniMotoJon

New Member
#7
#7
Thanks for the info guys! The carb was pretty gummed up.. Ill give it another once over when I install the new gaskets..This is the first Del Orto I have come across with no Needle.. It also has no way to adjust the float.. Seems simple enough.. ;)

Love your Restoration Post X-90 Rider.. Because of it I decided to restore it right... Looks too Rad complete and new... I sent the tank out for dent removal.. Ordered new (old Stock) rear Shocks, Blue Tank Decal, Gaskets, OEM petcok, Seat Cover etc... Parts are crazy expensive... :( Its missing the lighting system and rear fender.. Its gonna be some work to find the parts for the lights n such.. But I'm motivated now.. So slowly but surely!!

IMG_56471.jpg

Did these have a battery hidden somewhere or did they run off the magnito alone? Gonna read that manual but hate that they combined years and models...

Cheers and Thanks again for the quick replies!

Jon
 
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P

PAP

Member
#9
#9
It was a weird set up, too. The ignition system was wired up through the tail light that burned all the time. If the tail light bulb blew, it would not run. This was some kind of fuse for the magneto. I always kept a spare bulb stashed on the bike somewhere.
 
MiniMotoJon

MiniMotoJon

New Member
#10
#10
PAP said:
It was a weird set up, too. The ignition system was wired up through the tail light that burned all the time. If the tail light bulb blew, it would not run. This was some kind of fuse for the magneto. I always kept a spare bulb stashed on the bike somewhere.
Click to expand...
Thanks again! Ya I only have two wires coming from the engine.. One goes to the Ignition switch and then onto the coil, the other strait to the coil. I did test with volt meter and I get ranging voltage from 6v to 11 or so Volts on one side of the coil and the other is unreadable and all over the place...

Did the lights run off of those wires alone? Adding a wire harness to my parts list... ;)

I did clean the carb again and put the new gaskets in.. The kit didnt come with the top slide gasket but thankfully it is in tact..

The bike now starts fine with the choke up and idles good when its warmed up.. No test ride because I already had a tire off for tube repair.. I then came across the X90 riders thread and decided to re coat everything that needs it.. Now I know it runs, its time to take it apart, change fluids, clean, paint, powder coat and zinc coat..

Maybe a new thread to come... Thanks for the help guys!!
 
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