87 Spree - No power

[Dragonfish42]

I have had my spree for a couple years now and last season it ran great. When I first rode it this year though, it was hard to start and would die under heavy throttle so I did the following:

Replace battery
Replace bystarter
Full carb cleaning
Replace slow jet with brand new

After that it starts easy and runs and revs really nicely while on the center stand, but as soon as the back tire hits the ground it wants to die. If I keep the RPMs up I can kind of putter around but it gets worse as it heats up.

First I thought maybe drive belt or clutch issue so I pulled it all apart, cleaned the bendix in an ultrasonic and lubed it (it didn't work very smoothly so I did this just because it was already all pulled apart) Cleaned/lubed the clutch and hit the shoes with a bit of 80 just to deglaze them. None of that helped.

Next I cleaned the exhaust out because people were telling me clogged exhaust but it never really seemed clogged but I went through it with heavy duty oven cleaner a bunch of times until nothing more came out. That still has not improved my issue.

What's next? I suspect maybe blown head gasket or maybe an issue with the rings but I'd love to hear suggestions. The only other symptom I've noticed is that it's smoking a lot more than it used to.

Thanks!!

[noiseguy]

Your bottom end may have filled up with oil over the winter. Check your plug for fouling. For rings, you just need to check compression.

The "dies under WOT" is often air leaks around the intake / airbox. So check those. I'll let other chime in about the main bearing seals, which I've heard are starting to fail on all these bikes due to age.

[Dragonfish42]

I'm betting you're right about oil in the crank case. I just rented a compression tester and got 120 psi so that should be good. Also, I think I might have just bought a reed and gaskets from you unless the username is a huge coincidence