So last night I picked up an 89 883 with under 10k miles off craigslist cheap, guy said it needed work but starts. When he started it last night there was gas coming out of the intake side of the carburetor while cranking, back fired through the carb a couple times, then started on 1 cylinder... I figured it probably needed a carb cleaning no big deal...

So this morning as I'm working on it I noticed both the cylinders look fresh, not "weather worn" like the rest of the surfaces of the motor.... So I clean the carb, put it back together and it's doing the same thing, gas comes out of the intake side of the carb while cranking, back fires, starts on one cylinder, I was able to rev it up and get both cylinders firing but it didn't stay that way for long...

Anyway I'm starting to think it's a timing issue, what do you guys think???? Would really like to get this thing going so I have something to put around on until my bagger is finished...

 

could be a burned valve (not too likely) .. but my money is on the timing being screwed up, I would pull the timing (points)cover off and give the inside a good look see, I have seen a good amount of the older bikes have water damage in there...or someone might have screwed up the cam install..I have read about folks taking the cam cover off to polish it not realizing that the cams will come out with it....

 

oh, and check for water in the gas...

 

I'd do a compression test first, it sounds like you might be getting compression pressure leaking backwards through the intake.

 

Any videos or write ups on how to check timing on these motors? Looks like my timing cover is riveted on.....?

 

Here is a video I took with my iPhone, seems to run fine at a decently high rpm can you can see, but if I let it drop below a certin point it will sputter and back fire through the carb

 

Did you put a new set of plugs in?

 

Here is what I would do:

Confirm you have a strong spark going to 2 good spark plugs

Pull the tank and petcock. Wash out the tank and clean the petcock screen

Fresh fuel

Complete carburetor rebuild vs. cleaning

Replace both manifold intake gaskets (between the heads and intake manifold)

Rivets are in place at timer cover, so likely not a timing problem

 

change ur plug wires to eliminate the easy stuff check plug gap also

 

Clean the carb
dont panic