[Legends17]

I have a '97 blackbird (carb) that I just bought. It will not run. I have compression, spark and fuel, but it will not run. It won't even run with starting fluid sprayed in airbox. The only thing it will do is pop and backfire. I'm leaning towards a timing issue, but hoping it's something more simple. Thoughts?

[Phadreus]

Could be timing for sure...If you baught it used, do you know if it sat for a long period of time without being run?

[Legends17]

The bike sat for about a year and a half. I know the carbs need to be cleaned out and the fuel tank dumped. But, it should still fire on starting fluid. I guess I'll have to at least verify the timing. How difficult of a job is that?

[Wrench_Whore]

Adjust the valves, clean the spark plugs, rebuild and synchronize the carbs.

[Wrench_Whore]

Originally Posted by PaRider

May have a bent valve....

If the compression is within spec - no bent valves.

[Wrench_Whore]

Motorcycle function is straight forward, simple as the triangle of fire.

All you need is compression, the proper air fuel mixture and spark at the right time.

Granted, technology has introduced significant complexity to each of the required aspects...

BUT

when you accept diagnosis as being "the systematic elimination of variables", fixing any motorcycle becomes a simple step-by-step stroll through the park.

[cbr99xx]

Air, Spark, Fuel.... Gimme fuel , Gimme fire, Gimme that which I desire.

The above post simplified.

[denzee]

Do not under any circumstances Legends17 use starting fluid if you want it to ever start. With a high compression engine you'll put a hole in a piston or bend a connecting rod. The others are right about comp, spark and fuel but I would stick to the easier things first. get more into it as required.
First what is the history besides how long it sat. Did it run when it was last parked? Where was it parked? Outside with a cover, garage whatever.
Now how are you checking for compression, spark and fuel? I don't know your background mechanically but you can tell if an engine has good even compression by the way it cranks over. Is it even sounding and so on. Testing spark can only be achieved with a tester. Pulling a wire a throwing a test plug in it doesn't work. Weak spark will still show when not under compression pressure. Wether you have fuel going into the cylinders can't be know really without going inside to see a plug.
What I'd do is if the history is favourable and it did run when parked, the cranking sounds good and even, indicating it is mechanically ok, pull the plugs after trying to start with choke on. It's a pain on these bikes I know but it's the only way. If they are wet and I suspect they will be, replace them. While they are out, check for spark with a proper tester. Also test compression at this time if necessary. Don't go tearing it apart if the compression isn't perfect because from sitting, rings and valves tend to not seat well until after it is run again. Good luck and let us know more info if possible.

[bikemail]

hmmm... the last thing the original poster said was...

Originally Posted by Legends17

The bike sat for about a year and a half. I know the carbs need to be cleaned out and the fuel tank dumped. But, it should still fire on starting fluid. I guess I'll have to at least verify the timing. How difficult of a job is that?

and that was back in July. I'll bet he's changed that old fuel and gotten it running by now...

These blackbirds seem to be some reliable beasts. I want one.

-Greg.
-Ohio and Indiana.
-BMW.
-looking for a Blackbird...

[denzee]

I see that now bikemail. Should have noticed. After all that typing too! Oh well, I should smarten up and look at the original date. The thread came back up as new posting because cbr99xx had that cool line about air, spark, fuel...I'll have to remember that one!

[CoolBikeRider]

oil

[Twincam]

Whats the status on the bike now? Did you ever get it running?