No vroom vroom:(

[Nikolas]

Slowly but surely I'm progressing on this 89 rat project.  I did a quick clean of the carbs (bowls and jets,) derustified the tank, replaced all the fuel lines, and put in a stock replacement unipod.  It will start and idle with full choke.  Without choke it sputters and dies.  It will rev (again only with choke) very slowly and 'stick.'  The left plug is a dark brown and the right is more of a tan.  All these signs indicated a lean condition to me, especially in the right cylinder.  I also noticed the left exhaust valve is a little tight (may not be out of spec, my smallest feeler is .04mm.)

Any other insight?  I'm starting to think getting this bike wasn't such a good idea.

[Jarrett]

Slowly but surely I'm progressing on this 89 rat project.  I did a quick clean of the carbs (bowls and jets,) derustified the tank, replaced all the fuel lines, and put in a stock replacement unipod.  It will start and idle with full choke.  Without choke it sputters and dies.  It will rev (again only with choke) very slowly and 'stick.'  The left plug is a dark brown and the right is more of a tan.  All these signs indicated a lean condition to me, especially in the right cylinder.  I also noticed the left exhaust valve is a little tight (may not be out of spec, my smallest feeler is .04mm.)

Any other insight?  I'm starting to think getting this bike wasn't such a good idea.

If it was lean, the plugs would be grey or white.  Mine is lean and those are my colors.  If it's below 65 degrees, I can't start my bike without full choke.  You should go ahead and rejet and adjust the valves.  Don't forget to put an inline fuel filter on too.

[CirclesCenter]

Have you cleaned the carbs out in some solvent?

What jet size are you running?

Altitude?

Old fuel? (30 days = death, and really don't debate this kids, I'm in the industry. I don't care what you "think" I see these day in and day out.)


What I am thinking is that you have something stuck in a metering orifice.

[Nikolas]

Cleaned them with carb cleaner, but I didn't take them apart as much as I could.  I'm at sea level, stock jets, fresh gas, inline filter.  I just want to hear her sing, no load, on the centerstand before I start investing that much more time and money in this thing.

I just cleaned and shimmed the needles and lubed the slides.  I'll have to wait until tommorow to see how that worked since everythings tucked in.

[Jarrett]

In stock form, these bikes take forever and a day to warm up: IE, it will stall out with no choke in cold weather before it's warm.  Get it in good enough shape to ride.  Go one size up on jets, and take it for a spin. 

[DerekNC]

There's o-rings on the rubber intakes from the carbs to engine. I'd replace those as they're cheap. Also if you're completely stock I'd go up one size on the jets, clean the carbs completely and replace all o-rings. Adjust your valves also. After that I'd be willing to bet your bike would be so reliable you'd bet your life on it. I was in the same situation with my bike. It's rock reliable now.       

[Nikolas]

Alright, I recleaned the carbs completely.  The needle jets were the culprit, they're all squeaky clean now and it does indeed go vroom vroom