petcock diaphragm x 2?'s

[Jeff Saline]

#ygrps-yiv-2050522386 .ygrps-yiv-2050522386ygrp-photo-title { TEXT-ALIGN:center;WIDTH:75px;HEIGHT:15px;CLEAR:both;FONT-SIZE:smaller;OVERFLOW:hidden;} #ygrps-yiv-2050522386 DIV.ygrps-yiv-2050522386ygrp-photo { BORDER-BOTTOM:black 1px solid;BORDER-LEFT:black 1px solid;BACKGROUND-COLOR:white;WIDTH:62px;BACKGROUND-REPEAT:no-repeat;BACKGROUND-POSITION:center 50%;HEIGHT:62px;BORDER-TOP:black 1px solid;BORDER-RIGHT:black 1px solid;} #ygrps-yiv-2050522386 DIV.ygrps-yiv-2050522386photo-title A { TEXT-DECORATION:none;} #ygrps-yiv-2050522386 DIV.ygrps-yiv-2050522386photo-title A:active { TEXT-DECORATION:none;} #ygrps-yiv-2050522386 DIV.ygrps-yiv-2050522386photo-title A:hover { TEXT-DECORATION:none;} #ygrps-yiv-2050522386 DIV.ygrps-yiv-2050522386photo-title A:visited { TEXT-DECORATION:none;} #ygrps-yiv-2050522386 DIV.ygrps-yiv-2050522386attach-table DIV.ygrps-yiv-2050522386attach-row { CLEAR:both;} #ygrps-yiv-2050522386 DIV.ygrps-yiv-2050522386attach-table DIV.ygrps-yiv-2050522386attach-row DIV { FLOAT:left;} #ygrps-yiv-2050522386 P { PADDING-BOTTOM:3px;PADDING-LEFT:0px;PADDING-RIGHT:0px;CLEAR:both;OVERFLOW:hidden;PADDING-TOP:15px;} #ygrps-yiv-2050522386 DIV.ygrps-yiv-2050522386ygrp-file { WIDTH:30px;} #ygrps-yiv-2050522386 DIV.ygrps-yiv-2050522386attach-table DIV.ygrps-yiv-2050522386attach-row DIV DIV A { TEXT-DECORATION:none;} #ygrps-yiv-2050522386 DIV.ygrps-yiv-2050522386attach-table DIV.ygrps-yiv-2050522386attach-row DIV DIV SPAN { FONT-WEIGHT:normal;} #ygrps-yiv-2050522386 DIV.ygrps-yiv-2050522386ygrp-file-title { FONT-WEIGHT:bold;} Mark, Listers,   You are correct the vacuum line has nothing to do with fume recovery.  The vacuum is created when the engine is cranking or running.  The vacuum overcomes spring pressure on the automatic shutoff and allows fuel to flow from the petcock if the selector is in on or reserve and the fuel level in the tank is above the selected draw straw.  When the vacuum stops, spring pressure closes the shutoff and fuel flow stops.   I had a leaking petcock diaphragm on my 2003 KLR in maybe 2009 or so.  It was allowing fuel to be sucked into the intake tract and caused a rich air/fuel mixture.  That was causing a stalling issue at idle when the engine was hot although under running conditions all seemed fine.  Turning the idle speed up opens the throttle valve and allows more air and leans the mixture.  That often allows the engine to run at idle but now the speed is too high.  The fix is to replace the petcock diaphragm or convert to manual operation using the blockoff plate setup or changing to a manual petcock.  At the time of my failure I had a vacuum diaphragm RevMaaatin had given me that he bought from Fred at Arrowhead Motorsports.  That fixed the problem in about 20 minutes.   One other issue that happens with the vacuum shutoff is the vacuum line can be old, hard, cracked etc and not seal well.  If the vacuum isn't consistent and at full (negative) pressure the shutoff valve may not open all the way or operate correctly.  Two weeks ago Martin replaced the vacuum line on his KLR as his old one was very hard.  He bought a new part from Kawasaki and it was very supple and longer than needed.  This is the bike we used to do a fuel delivery test getting one gallon of fuel in three minutes.  He has had very good engine performance since making sure the fuel system is working well.   I don't know how often the vacuum diaphragm fails but I know when it does it can cause some hard to figure out problems.  For the cost of parts I don't think it would be tough to change it after 6-8 years of use and maybe half that time if you are using fuel with ethanol.  It is usually easier to fix in the shop than on the side of the road.  But even the side of the road isn't too hard.   Since this is Vendor Friday I'll mention I do sell the blockoff plate setup.  The setup includes the blockoff plate with gasket and bolts, a cap for the carb vacuum port and an allen wrench for the bolts.  If someone wants one the cost is $20 US in the states and $24 US for Canada.  Sorry, postage is expensive to Canada.  : (  If you want one send me an e-mail at salinej1@... and include your mailing address.  I'll send the setup and include a stamped addressed envelope for return payment.  For Canadian orders you have to stamp the envelope.   Best, Jeff Saline The Beautiful Black Hills of South Dakota 75 R90/6, 03 KLR650 . . . . . .     ____________________________________________________________ [b]Do THIS before eating carbs (every time)[/b] 1 EASY tip to increase fat-burning, lower blood sugar & decrease fat storage info.fixyourbloodsugar.com