My old XN85

[lomsavage]

Given the number of joins in the exhaust, lack of boost (and "blobs" on gauge) could be one or more leaks between head and turbo.
Last "short" bit is favourite to go given its totally inaccessible position.

Also try checking "end float " on turbo spindle, they are prone to wear despite have a "constant loop" oil feed, however as they where an off the shelf turbo unit and not unique to bike there should be a specialist around that could rebuild it if necessary.

H

[lomsavage]

just in case you doubt my "credentials" for commenting on "obruts",

this one was my secoond (now living just outside Chicago)

first was 92/93

[mikefido]

When I get a chance I'll have a look at what you've suggested (and as I mentioned I need to take the clocks apart to remove before mentioned woodlouse) ... just enjoying riding one again at the moment