Can't find it...

[planedick]

I know that somewhere here there is a chart to recomend jetting for various modifications like exhaust and pods... I can't find it and the search doesn't seem to find it either.. Does someone know where it is and can point me..

Bike is running good, but after riding that XJ I decided that mine wasn't running as good as it could. Today I did the fast run under load and chopped the ignition and looked at the plugs. White, no color at all. I tried changing the mains from 137.5 to a set of 110's I had and now it's a little better color, but much stumbling on hard exceleration. The 110's were only a few thousands of an inch larger than the 137.5's and I probably need to go at least one more step bigger. I was also wondering about the air jets.

[nutwister]

The 110's were only a few thousands of an inch larger than the 137.5's

How do you figure 110s to be bigger than 137.5s

Bigger # bigger jet.

[dbeardslee]

Jetting Recommendations

[tinman905]

You are going the wrong direction , #140 is the next bigger size . #110's are used in the later 80/81 carbs.

[planedick]

Bigger

I measured the hole in the jets with wire guages. They were a set I took out of another set of old carbs. Maybe they had been drilled out. They were only .003" bigger than the 137.5's

[planedick]

Thanks

Thank you dbeardslee for the link. One of the other problems I have is when I synch the carbs I'm able to get them right on at idle, but cracking the throttle just a little makes them go WWAAAAAY off so when it's running at throttle nothing is balanced at all.

[dbeardslee]

I think they all pretty much do that. You can only really sync them at idle. You could always try a poor mans YICS - after you sync, tie the vacuum taps together with 'T' connectors and vacuum line. Some members say it makes them run smoother, and some say it makes them run like crap. I haven't tried it yet, but I'm thinkin' about it.

[planedick]

I did

I tried that, but the lines are too small to make it work and it did run worse. I figure that if the ports were around 3/8" Dia like the YICS head it would probably work better.

[madmax-im]

A word to the wise about those jetting reccommendations...that formula will get you in the ballpark...but it has been my experience that this is not exact. In using this formula for what I thought I needed for jetting only to find that the bike was still too lean...so if you find after all this that your bike craps out at WOT then you're prolly still too lean. FWIW YICS sucks..I have the YICS eliminator tool permanently installed blocking off all the YICS ports and the bike runs sooo much better.