CARB BALANCE

[Herb]

I took the bike out for a rid yesterday, jsut didn't have what it should and it was rough, a lot of vibration. I got to figureing and decided it had been 8 years since I did a carb balance, it is a wonder that it ran as well as it did.

A few weeks ago I replaced my broken balance check system with a set of vacuum gauges.

This morning I got out in the shop and did the balance. It was so far off that I thought I would never get it right. Finally got the idle spot on and started on the high speed. I was getting close and then no matter what I did the front cylinder vacuum stayed the same. Started looking and found that the vacuum hose had fell against the cylinder and melted. when it melted it it sealed both ends keeping the vacuum at one point.

After letting it cool down I cut the hose and reattached it, I included a wire to hold the hose away for everything hot.

When I restarted I had the high speed so far out it was pathetic. Seemed to take forever to get it dialed in but finally got there. both low and high speed are spot on.

Let it cool down and put the tank back on, fired it up and it sits there ticking over at 700 rpm. Took it out for a 50 mile run down highway 50, hit the 70 mph speed limit and it was so much smoother than yesterday... Ran it up past the limit and it was sweet to ride.

So nice to have it right again...

[hillsy]

Carbs in sync make bikes behave a lot better in the real world than you would think.

I remember having a nightmare of a time balancing the z13 carbs (3 x dual throats) - and one pair was WAY out as well.

Took ages but once I got the "odd" one close to the others the bike just started to sound better all round.

[Herb]

I was talking to my son this evening about the bike and the sync. He just laughed, his Busa is fuel injected and has never needed any thing but one new set of plugs in over 60,000 miles.

The hardest bike I ever had to keep in sync was the GT 380. 3 carbs with seperate cables and 3 sets of points.

let the points get out of adjustment by even 2 thousands and it ran like shit. On top of that the 3 seperate cables seem to get the carbs out of sync on a regular basis. I had to resync everything about every 4-500 miles.

When the bike was running right it was a blast to ride but just a little out and wouldn't keep up with the Yamaha R5 350.

The GT 500 was a little better, the carbs were all linked with a shaft so they were good for a long time but it still had 3 sets of points that had to be set exactly the same or it lost power and every time I reset the points, like the 380, the timing had to be reset.