The group moved from Helsinki to Stockholm in 1980 and then to London in 1982 and continued to gain fans and influence the music scene there.

In London, Yaffa, along with Hanoi Rocks bandmates Nasty Suicide and Razzle, as well as Knox of the Vibrators, recorded an album under the name Fallen Angels.

Knox continued to perform as Fallen Angels after, though the Hanoi Rocks members including Yaffa never played with the band on stage.

After Razzle's death in 1984, Yaffa left Hanoi Rocks and formed Chain Gang with Pelle Almgren in Stockholm.

The year 1987 saw Yaffa doing a couple of gigs with then London-based Johnny Thunders and Jerry Nolan, both of the legendary group New York Dolls.

He was credited as Ulan Bator for contractual reasons with Jetboy who was at the time signed to MCA records and was asked not to use his real name.

Yaffa moved to New York City in 1990 to join Hanoi Rocks frontman Michael Monroe and started a new band Jerusalem Slim.

From 1990 to 1993 Yaffa played frequently with a band called Love Pirates with Gass Wylde of the Pretenders and Manish Boys.

Earlier in 1993 Yaffa and Monroe recorded Steppenwolf's song "Magic Carpet Ride" with Guns N' Roses guitarist Slash for the movie Coneheads.

Along with drummer Eric Kuby, this trio released one CD, titled "Two Songs" Sami also played on, produced and recorded Ricky Bacchus's first solo album "Luckiest Girls".

In the sixth episode of season eight Yaffa travelled to Helsinki with Anthony Bourdain to show him all his favourite culinary spots and other strange places Finland.

The second solo album titled "Satan's Helpers War Lazer Eyes And The Money Pig Circus" was released in March 2024 through Vallila Music House and Cargo Records.