balancing the throttle bodies

[kblahetka]

So I took off the plumbing and balanced thr throttle bodies. They were all 610, 630, 620 in tune ecu.

I put everything backtogether and must have disconnected a vacuum line so I had to pull it apart and do it again. Now the throttle bodies all read 820, the bike doesn't pop on decal anymore and it seems to run fine, but why the big jump in that number? Do I have an air leak or something?

 

[scot in exile]

Someone will come along and answer your main question but when you had all the plumbing off you should have installed the K&Ns.

 

[kblahetka]

I'm throwing this out there, the bike popped on decal when I got it in August. I added a map from @HansO to fix that and it still popped. I took it down the street with no plumbing and it still popped. When I put everything back together it stopped. I hooked up the PC again and cyl 1 is a bit off, I read on the other forum that it usually happens when piecing this back together.

So my thought is that they are close now and the bike runs good, I'm wondering if I had an air leak before I did this and that's why I had all the popping. And that's why the cyl reading numbers jumped. Any thoughts?

 

[warp9.9]

Sounds like a viable reason. Now ride it a while and make sure she holds in there.

 

[kblahetka]

Someone will come along and answer your main question but when you had all the plumbing off you should have installed the K&Ns.

Believe me, the next time I have to do this I'm taking all that crap out of there.

 

[Speedy]

Something is wrong! The higher the number, the higher the manifold pressure, or put in different terms, your bike is running with a lot of throttle just to keep running (very low vacuum), or you have the vacuum lines incorrectly connected or one line is loose or disconnected.

The tubes running to each throttle body are the same length and the one from the connector to the sensor is shorter. When running and warm the manifold pressure will read in the low 600's at idle on a stock bike, in the mid-500's with a richer tune and changes to the timing tables, and in the low 500's with a header and less restrictive muffler. At wide open throttle the manifold pressure should read about 960 at sea-level. All three throttle bodies should be within 10 millibars.

The ECU uses the throttle position sensor, rpm sensor and manifold pressure to determine engine load and hence fueling requirements, so even if it idles and appears to run right, it isn't and will throw a check engine light soon. Don't ride until you find the problem and resolve it. IMHOP

 

[kblahetka]

Something is wrong! The higher the number, the higher the manifold pressure, or put in different terms, your bike is running with a lot of throttle just to keep running (very low vacuum), or you have the vacuum lines incorrectly connected or one line is loose or disconnected.

The tubes running to each throttle body are the same length and the one from the connector to the sensor is shorter. When running and warm the manifold pressure will read in the low 600's at idle on a stock bike, in the mid-500's with a richer tune and changes to the timing tables, and in the low 500's with a header and less restrictive muffler. At wide open throttle the manifold pressure should read about 960 at sea-level. All three throttle bodies should be within 10 millibars.

The ECU uses the throttle position sensor, rpm sensor and manifold pressure to determine engine load and hence fueling requirements, so even if it idles and appears to run right, it isn't and will throw a check engine light soon. Don't ride until you find the problem and resolve it. IMHOP

Thanks, I went and looked at it and I think the vacuum lines were crossed, it's now in the low 600s. I have D&D pipe, a stock airbox, and a tune from Hanso. It's currently about 30F degrees out. Sound reasonable?

 

[Speedy]

Yes, Glad it was that simple. Good riding.

 

[HansO]

Just saw this and Speedy is right on the money in both posts, as far as it still poping you must have an exhaust leak somewhere, put some very soapy water on all exhaust connections while cold an start mottor and quickly observe for bubbles for it get hot that includes the flanges on head too, I had slight leak on my bike when it was new caused popping with std exhaust fixed with hi temp silicon

 

[kblahetka]

Actually the popping has died down dramatically. I assume no more than what you would have with a stick pipe. I'm thinking I had some leak at the intake and it was leaning it out which explains why it would pop with no filters and stop when the intake was back on?