Backfiring or popping on decel is usually a lean condition but you know how it sounds better than I do.
Congrats on the big cube engine, i'm going that way ASAP.
Enjoy.

 

Glad to see your on the road I've got 600mi on my 120 three oil changes last one to syn.
the only thing I've had to do is adjust the float Had fuel coming out the vent tube I also
hooked up a voes per mia's suggestion seems to run about 10 degrees cooler This motor is way quieter than my 113 with mods And the power is better seems smother less peaky
good luck have fun

 

Do not change the needle you are looking for trouble without a dyno and AFR meter, the needle basically comes into play during the transition phase/WOT not at closed throttle. One notch up or don from center will work on 99.9999% of all Ultima engines. Check for an exhaust leak. Remember if you are running straight pipes, the open end is getting more unburnt fuel(this is normal) than it saw before so you will get more decel popping. Hope this helps.
John

 

Do not change the needle you are looking for trouble without a dyno and AFR meter, the needle basically comes into play during the transition phase/WOT not at closed throttle. One notch up or down from center will work on 99.9999% of all Ultima engines. Check for an exhaust leak. Remember if you are running straight pipes, the open end is getting more unburnt fuel(this is normal) than it saw before so you will get more decel popping. Hope this helps.
John

 

Hi all. I now have 1500km on the new engine. It ripped out the clutch when i got the dyno tune. Started to slip at about 115 hp and 104 ft lbs torque at 4900rpm. I put in a barnet extra disk clutch but it just would not hold. Now I have ordered a Rivera Primo Pro Clutch Kit and hope it will hold up. The engine runs strong but do get a little noise rolling down the road at 3000rpm no load, quiet under load or decell. sounds like piston slap on the front jug. When I got it on the dyno it was rich from off idle to wide open, between 11 to1 at idle to 12.5 to 1 at full pull. when we changed the main jet needle clip and idle to about 13.7 to 1 it ripped out the clutch. I will have to take it back after the new clutch is in. Is the Rivera Primo Pro Clutch Kit a good kit or should i use something else? The noise is not getting worse but I am concerned about it . I was told it is lifter noise but that would be there all the time not just no load. any thoughts?

 

The pro clutch is a good choice That's what I run and have had no trouble I use B&M
trick shift oil My 120 has 127hp/126tq

 

Your gonna love that motor. I put a 113 El Bruto with the Ultima Open primary, 6 speed tranny and their starter in my 97 FLSTS a year and a half ago. I talked to a guy that stuffed a 113 in his and had problems getting a clutch to hold up so I decided to go all Ultima since the guy I talked to said it was made to stand up to the engine. I have just over 20K on her and shes a monster. Had her dyno tuned after break in and even with my Vance and Hines true duals she was putting down 118 torque and 100 HP. Guy that did the dyno said that different pipes could bring up the numbers but hell its a 97 springer not a cafe racer. As it is I can bring the front end off the ground at will if I band her off the line.

As for the popping on decel. I get that too. It is a sign of running lean usually but my dyno tune and my plugs say I'm tuned just perfect. I recommend changing to an Odyssey battery or one with the same specs. I couldn't find a battery to consistantly crank her til I jumped up to 550+ cranking amps.

Good luck and enjoy

 

Thanks for all the help, this thing rocks, fastest bike I have ever had. It just has so much torque the rpm jumps as fast as you turn the throttle.

 

That is an amazing springer. Makes me want to replace my motor right now.