Tyco announced that they acquired Schaper on Sept 5th, 1986. The funny thing is that the 1985 Tyco catalog (see page here) includes the US-1 STOMPER Electric Trucking "high adventure set" (No. 3211). It's your basic electric car racetrack but you get one vehicle that looks like a Stomper pickup and one that looks like a Stomper Blazer.

Tyco sold Stompers for three years. From what I can tell, Tyco did not make any major changes to the various stomper lines. It seems like the changes were more cosmetic than anything, basically different paint schemes and "stickers". My limited examples include a Mini for land, 6 Water Demons for land & water, and 2 (of 6) Diving Devils for land, water, & underwater (plus they came with a little guy). It's also interesting to note that the special McDonald's Stomper that you had to send away for was manufactured by Tyco! Below you find a list of manufactured items for 87 and 88, courtesy of Rex.

 

1987

Stomper Speedsters twistrack Gator Rally Set	No. 60586
Speedsters Twistrack Set	No. 60567
Speedsters Stunt Set	No. 60577
Stomper R/C	No. 61047
Stomper Diving Devils	No. 61017
Water Demons	No. 60697
All Terrain Vehicle	No. 60827
Off Road Hopper	No. 60927
Mini 4-wheel Drive	No. 60837
Bully	No. 61097
Stomper 4x4s with Road Blocks	No. 60867

 

1988

Speedsters Stunt Set	No. 60577
Speedsters Twistrack Set	No. 60567
Stomper 4x4s	No. 60868
Stomper R/C	No. 61047
All Terrain Vehicle	No. 60827
Off Road Hopper	No. 60927
Mini 4-wheel Drive	No. 60838
Bully	No. 61097
Stomper Diving Devils	No. 61018
Water Demons	No. 60698

 

1989

I stumbled on the two stomper pages (seen here) from the 1989 Tyco catalog and can verify that Stomper 4x4s (60868), Stomper R/C (61047), Stomper Diving Devils (61018), and Water Demons (60698) were all still very much a thing. It's a little strange that the part numbers changed from 87 to 88 but not from 88 to 89, but I'm guessing that's a sign that they were giving up on them.