86 350x help

[dream3wheeler]

I got a new exhaust and carb for my 350x. Bought a brand new 400ex carb. Hard to start to say the least. When it finally does start it sputters and wont idle. Im assuming i need to jet it. What jet kit should i get?

Also when i took the original rusty head pipe off the two inner bolts ripped right off and are stuck in the cylinder head. I've heard this is pretty common. Any tips on getting those out?

[RIDE-RED 250r]

I got a new exhaust and carb for my 350x. Bought a brand new 400ex carb. Hard to start to say the least. When it finally does start it sputters and wont idle. Im assuming i need to jet it. What jet kit should i get?

Also when i took the original rusty head pipe off the two inner bolts ripped right off and are stuck in the cylinder head. I've heard this is pretty common. Any tips on getting those out?


Take it to a reputable machine shop! Don't try to take those out yourself. Steel bolts, seized into an aluminum casting are almost impossible for the average shadetree guys like us to successfully remove without ruining the head.

[jays375]

You need to go bigger on the pilot.Look for some posts on fixing exhaust studs.Need to pull the head to fix.Next time use a torch and be gentle.I even removed the front forks when taking exhaust off.

[barnett468]

Hello


Since this carb is new to you and jet sizes are unknown I would do the following on the carb.


If gas is a year old or more change it.

Install new std plug, no fancy tips.

Make sure air filter is clean.



GAS LEVEL TEST – Take a 12” clear tube and attach it to the float drain fitting, turn the gas on, hold the clear hose next to the carb with the open even with the top of the carb. Open float bowl drain screw and check gas level. It should be from even with the bottom of the carb body to around 3/16” below it.

If float level is incorrect then fix it and try again.

If it still runs poorly check the following.



NEEDLE POSITION - Test with needle lowered all the way [lean position] then raised all the way [rich position]. Make notes of the results then put needle clip in center position and proceed to next step.

If it burbles/sputters/misses upon acceleration it is rich so drop the main two sizes and try again.

If it does NOT burble/sputter or miss upon acceleration but simply fails to accelerate it is lean so raise main jet 2 sizes and try again.




PILOT JET – With the fuel mix screw properly set if the bike starts easily when the engine is cold and the air temp is around 58-68 degrees and it starts EASILY with 0- 1/4 choke, the pilot is too large and should be reduced 1 size.

If it requires full choke to start and is difficult to start the pilot is likely too small and should be increased by 1 size.

If it starts easily with full choke at 58-68 degrees the pilot jet size is anywhere from very close to perfect.