Bonneville America Forums Forums Technical Forums Performance Mods Balanced my carbs today

I finally put the carb balancer that I bought from Brent to use last night. It made a noticable difference in the bike's performance even though the vac difference wasn't but an inch or less between the cylinders. I'll be checking the balance more often now. Tomorrow, I'll have the 19mm spark plug socket from Sears (thanks tech vault) to install the Iridiums. If they make as much difference as the getting the carbs equal, I'll think I'm on a different bike.

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Tomorrow, I'll have the 19mm spark plug socket from Sears

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You need an 18mm, NOT the 19!!!

Thanks Pat, I had 18 mm on my list, just typed it wrong here.

I balanced my carbs last week, the first time in over 6 months. Balance consisted of hooking up the balancer, hit the throttle a few times and unhooking it. They were still right in sync. I must done something right the last time.

I stoped by my dealer today to have them check if my carbs were in synch. (cause I can't afford a carb tuner from Brent).
They checked them by using a laser thermometer and checking the temperature of the exhaust where they connect to the heads. 267F both sides. They said they were fine. I thought..... Interesting...
Does that sound like an ok way to balance the carbs? I hate to be doubting THE DEALER and all, but ya know.....?

P.S. The only reason I haven't made my own carb tuner is in fear of sucking all the fluid into the carbs.

I would think the temp thing is more a reading of how even the carb air mix screws are than the actual balance of the screw at the throttle linkage...

I have one of those laser temp guages. In posts of old I was told 2 things -
1. Chrome surfaces do not give you an accurate reading.

B. The temperature at the exhaust headers is probably much hotter than 267 degrees. I believe I read somewhere it can get up near 2000 degrees on some bikes under some conditions.

Draw your own conclusions...

Yeah, I wasn't having much faith in the dealers doings. I think they were looking at it from more of a "pipes blueing evenly" point of view rather than a carb synch point of view, now that I think about it.

Exactly. And that really has more to do with the screws than the actual vacuum balance between the carbs.

Tried balancing my carbs last night, couldn't get them to balance at idle and part throttle at the same time. Was monkeying with D-screws, idle, sync screw, got so confused I gave up. First time was a piece of cake.

They can be finicky little bastards. Comeone correct me if I'm wrong, but aren't you supposed to do it with an elevated idle? Like 1200 rpm-ish?

Does your dealer do that for free? Nice folks

I installed the Iridiums with a thin coating of anti seize compound on the threads, but can't feel a seat of the pants difference from the factorys almost 5,000 mile plugs. Maybe on a dyno, some gain could be realized, but the carb balancing made more difference on the America. A double manometer, (got my carb balancer from Brent) whether homemade or not is an essential tool for our bikes.