82 650L losing power at top end

[Guest]

Hey guys, my Gf's GS runs great but recently on our last two rides she loses power gradually at 70mph+ She describes it as if shes ran the fuel tank dry. Once she pulls over the bike fires up instantly and is totally fine until she gets back up to Hwy Speed.

My thoughts either an obstruction in the fuel lines/filter or perhaps a clogged jet?
Electrical system is original Spark plugs are gaped to manual spec

Any advice ??

[habsdoc]

Sounds like your tank vent could be clogged. If you have a spare key available, you can try loosening the gas cap when you start to loose power and see if everything returns to normal. Is your tank clean??? Petcock screen clogged??? Do you have an inline filter installed???

[tom203]

Yes, and check petcock for good fuel flow,both on "PR" and "ON" (for latter,attach some tubing to petcock vac fiting and suck). Consider just getting new petcock for about $50 and rule it out as an issue.

[jdcarr21]

great info! there is an inline filter. i may just replace it since im going to look into the petcock valve. Much thanks, Happy and safe riding!

[fastbysuzuki]

great info! there is an inline filter.!

Here could lie your problem, if you have an inline filter other than the petcock is not a good idea as the system is gravity fed and does not cope well with an inline filter as they slow down the fuel flow.

[tkent02]

Don't replace the filter, remove it.

[Nessism]

When was the last time you measured valve clearances?

Is the bike stock or modified?

Just for kicks you might want to check the Newbie Mistakes thread linked in my signature to see if anything applies.