1991 150 carbs

cowboyup

Petty Officer 2nd Class
Joined
Aug 5, 2004
Messages
155
While my powerhead is at the machine shop, i'd thought i would tackle rebuilding all 12 carbs (I've got twins). She's been on the hill awhile so i'd rather not take a chance on clogging a jet. Speaking of which, my jets are 57D (high speed), 44 intermediate and 34 (idle air bleed). My parts manual suggests using 57D, 47 and 36. Why the difference? Would i notice a performance difference? Also, my manual says to level the float to within +/- 1/32" from the top of the bowl gasket. Is there a jig or maybe a tool i can use to discriminate 1/32"? Thanks for your help.
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: 1991 150 carbs

Sounds like someone has richened up the motor for some reason. Assuming we are using the original 1991 6V6 carbs, I would take that as a red flag that the carbs have been richened, probably to offset a lean condition, and now the motor has to be rebuilt. <br /><br />On the floats you have a 1/16" to play with from up to down. Usually a straightedge will work to hit it in the middle.<br /><br />Good luck!
 

cowboyup

Petty Officer 2nd Class
Joined
Aug 5, 2004
Messages
155
Re: 1991 150 carbs

Thanks for the reply. The VRO has been disconnected (not by me). I've looked at the black oil hose but did not see a plug. Maybe this is allowing air to be sucked in and leaning out the carbs?
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: 1991 150 carbs

Either the oil inlet nipple on the pump, the oil inlet nipple on the lower cover or the hose must be plugged.<br /><br />If the hose from the tank is still connected to the lower cover inlet and that inlet is connected by a hose to the pump, it was still trying to pump oil. If there was no oil in the tank it'll pull air for sure.
 

cowboyup

Petty Officer 2nd Class
Joined
Aug 5, 2004
Messages
155
Re: 1991 150 carbs

Thank you sir. Should I concern myself with disassembly of the VRO for inspection? Is there any maintenance concerns i.e. float valve, vapor separator? Thanks again.
 
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