slothman

bad news- finally rebuilt the top end today- and now it won't fukin start. On top of it all- did a compression test with the same guage, and I'm STILL getting 80 psi after the rebuild. I hope my gauge is just a POS .... Also- I kicked it over with the start plug grounded to the pipe, and I'm not seeing spark. WTF could have happened? Tomorrow I'm going to dig into it- plugs seemed bone dry as well (like they weren't getting fuel) ...

If the compression tester is roughly the same size as the threads on the spark plug, it's going to fairly accurate. I think you might want to pull the head and inspect for cylinder/piston damage. 110 psi requires a top end rebuild.

Rich Symptoms: •Poor power output •Starts too easily when cold - requiring little or no choke. Responds readily to the throttle when cold. Runs worse as it warms up •Hard starting when hot •Ragged idle...due to "loading up" of unburnt fuel •Idle that tends toward lower rpms than expected based on the setting of the curb idle screw •Easily settles to idle, but has tendency to dip below set idle speed then recover...sometimes stalls •Strong pungent odor of unburned fuel •Buildup of black, dry, sooty carbon deposits on spark plugs. Bad cases of this buildup will foul the plug completely and kill that cylinder. •Excessive buildup of dry sooty deposits in the exhaust system •Responds to throttle, but sluggish •When fully warmed up, runs much worse when choke is applied. •Poor fuel mileage •Black "puffy" smoke during hard acceleration •Temporarily removing air filter element makes the engine run better. •Runs worse as you climb to higher elevations •Fresh engine oil quickly turns black from excess fuel dilution Lean Symptoms: •Poor power output •Hard to start when cold - requires excessive choking. •Lengthy warm-up required. •Runs better (but not good as it warms up) •Spark plugs overly clean..with no deposits or slight glazed appearance •Rough, erratic idle that drifts toward higher rpms than expected based on the setting of the curb idle screw. Sometimes a lean condition will cause a "hanging" idle that is slow to settle down to set idle speed. •Backfiring •Sluggish...hesitates when the throttle is opened, then recovers (often accompanied by a slight backfire) •Vague throttle response •Surging at steady throttle cruise operation •When fully warmed up, runs better when choke is applied. •Engine runs hotter than normal. Headers can turn cherry red in extreme cases! •Temporarily removing air filter element makes the engine run worse. •Unusual "sucking" noises in the intake area. •Runs better as you climb to higher elevations •Slight back-firing on deceleration. This normal tendency is controlled by the air cut-off

Did you sync them with a vac carb sync ?

Leakdown test will tell you lots. The system should hold 10lbs. Common air leaks occur around the reed valve gasket area. The air intake boots can also leak. Compression should be at least 115 psi in both cylinders. Especially with a fresh top end.

also, did you compression test after the top end rebuild ?

Those plugs look rich. Drop the main jet one size and then do a plug chop.

According to the service manual, stock Shees came with different option main jets: 200, 220, 240 I am not sure which jets were model/year specific. My stock mains are 200. I am pretty sure all stock pilot jet are 25. You need to do a plug chop to determine if you are running rich or lean. Black/oily electrodes indicate running rich. White/burned electrodes indicate a lean condition.

I also agree with 27.5 pilots....adjust slides (make sure half dome is facing the air filter too)....make sure floats are in correct carb (yes they are different)....turn air screw all the way in until it lightly bottoms out and back it out 2 turns

You also need to sync the carbs, and check the vac pressure with a carb sync tool. Here is some help:

Did it run after you pulled it out of storage? If it did, then you messed something up when you took apart the carbs lol. Make sure the slides are installed correctly (half dome facing air intake)

Did you keep the stock 25 pilot jet? Or did you put in something different? It is kind of weird that your plugs look black, yet you are only running a 210 main with pipes. Most people are in between 270-330 with pipes and no intake box.

ebay strikes once again !

So you're running 64.5 pistons in 65.00 jugs? I can't imagine that being good....

I don't think he's running lean. Look at the electrode. Looks black and oily. If it was running lean, it would look white or burned. If he's at a high elevation he won't need as much fuel. To the OP: you have stock OEM carbs, right ?

Looks too rich. Turn the screws out another 0.5 What is your elevation? Are you using the stock air box? Did you have 200 mains before you installed 210s ?

Are you at a high elevation? Like 2,000 ft plus? If so, the motor will need LESS fuel, meaning smaller jets. Your plugs are wet, which means rich, put in some 270 jets and see if that helps. Keep the screw at 2.5 turns out. Then do a plug chop.

If your plug is "wet and washed" after WOT, your main jet is too rich. Running rich will cause that hesitation you are talking about. You can try a 270 main jet and see if that leans it out the right amount. Are you running the stock air box? Do you have pipes? What elevation are you at?

Also, tune it with a carb synch like this one : http://www.ebay.com/itm/150734678585?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649 If you haven't already

It seems like you are leaning it out with the air screw to compensate for large jets....6 turns is way too much. If you are at 2.5 turns and the plugs are showing rich (black and oily), then you need to go with a smaller jet. Can you post picstures of the plug? Also, what jet sizes are you using right now?

really? What are the average outside temps for winter vs summer?

lesson of the day: don't always assume the motor is blown when you hear metal noises Glad you figured it out !

Ya just use a light coat of sealant, maybe some high temp RTV.

as mentioned, make sure everything is torqued to spec. After the engine warms up (after new top end) and have to let everything cool, and retorque the bolts.

Post pictures. Are you SURE it's leaking transmission fluid ? Kinda hard to mistake gas for tranny fluid, lol.