Terrible fuel economy after reseal & new rings.

[Mark633CSi]

I just took out the 82 Trailfire LX after having it all apart when I did a full reseal and new rings. It fires up and runs great settling into about a 1800-2000 rpm idle. The problem I'm seem to have, and I don't know if this is normal, is when I'm riding across the field I have the throttle 2/3rd's down just to maintain any kind of speed. When it's at that point the slightest application of throttle has it take off like a rocket. It's got lots of power but after 6 miles today I dammed near burnt half a tank! The carb was rebuilt by a shop here in town that specializes in John Deere snowmobiles. Everything is sealed up but it sucks gas like I've never seen.

I should note that on the first start up after the engine was back in, I was flooding like crazy. I smacked the bowl to see if the floats were stuck, it seemed fine after that. If the floats were stuck, you would think it would flood on start up which it doesn't. It starts in 1/2 a pull.

I'm thinking maybe there is still some varnish somewhere that's maybe come loose. It sat for 30 years, albeit with an empty tank.

Here's a couple videos of it. I don't know if some of you guys can tell by sound...? It's a long shot I know...

https://youtu.be/BIMgie_TdYM

https://youtu.be/0TsdJiDtN9c

As always, any help or ideas would be greatly appreciated!

[Matt]

From your description, maybe clutches aren't shifting properly and it's not going into the higher gear ratio. If you have a tach, do you know what the RPMs are when you are cruising at 2/3 throttle? Did you remove/inspect/clean the driven clutch, and are the 3 little plastic shoes on it good?

It never hurts to pull the carb back off to check it again. I usually end up doing that a couple times on fresh rebuilds.

[Mark633CSi]

Thanks! I'll check the carb tomorrow and I ordered 3 of plastic shoes. I'll let you know how it works out!

Thanks again!
Mark