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TrailBlazer 250 Oil Bypass

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I don't think you will see oil flowing.   Its a slow flow plus the dark color. 
Most of the oil tanks are a light plastic color so you can see the oil level.  If you have doubts the oil is not flowing you can mark the tank's oil level  with a marker and monitor it. If your sure its not working then yea you can pre mix and be done.     

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Is there a reason to block it off? I’m positive it’s dead, I replaced the line from the pump to the carb and see nothing. And that working the pump at idle. Can I just leave it and run 40:1? See how it goes? Get it magically starts working again, I guess I’ll know quick.

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Ok so here’s where I’m at. I bypassed the Oiler and went to 40:1 mix. Pulled carb and cleaned because it wouldn’t idle. Runs perfect now, but hangs rpms.... if you rev it slowly revs back down. Normal on these old 2 strokes? I checked to make sure nothing was sticking on the throttle. It drops right jack down. Also what is the air mixture screw setting suppose to be? I’ve seen mixed thoughts from 1 turn to 2 1/2 turns..... would sucking air cause it to hang rpms? Doesn’t do while riding that I notice just when you free rev it.

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Slow return to idle generally is caused by a lean condition.  Lean condition can be caused by either too small of a main jet or too much air rushing in.  I'd check for vacuum leaks personally.  When you bypassed the oiler, did you block off that port?  I would seriously doubt it's caused by too small of a jet, but i guess could be a partial obstruction.  May also check the throttle butterfly closing without the cable attached.  I had one a bit ago that had a bit of stickiness in the throttle just enough to not slap shut the way it should.  Ended up needing a good soak and some light oil and it slapped shut afterwards and stopped the slow return to idle.

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I pulled belt cover and sprayed starter fluid behind the clutch while it was running, with no effect in rpms. Also sprayed all of the carb and intake boot, along with pull start start of the crank. Nothing caused a spike in rpm. Would the muffler having the end cut off cause the rpms to hang from lean condition? I know on 4 strokes, specially cruiser bikes if you cut the pipes you usually have to rejet it....

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Have you actually looked into the back of the carburetor and opened the throttle and let off to see that its just not a cable issue? 
Leave the engine off and look into the back of the carburetor with no air filter on.   Press the throttle all the way and let it go quickly.  See if it slowly closes.  If so it could be a throttle cable that has a worn lining or I've seen a throttle cable not routed properly and to close to the engine head. It melted causing the inner liner to melt and bind the cable.   

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Pull the slide back out and try it while its out of the carb.  See if it moves freely that way 

If so  then its internal to the carburetor and may be the main jet port where the needle slides in could be scuffed or damaged. Also check the needle and make sure its not bent. 

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I had a carb apart recently that had a bit of sand through it (mud/water 4x4) and it scarred the slide and throat.  Just had to take it out and work the slide and throat real good with a brown paper bag.  Slid up and down flawlessly afterwards.

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