Wilsons Sandbox

On Thu, 24 May 2012 20:59:53 -0700 (PDT) Larry Ostrom writes:

> I have two KLR's and one of them, when I have a strong tail wind, > will start to > miss and even backfire. It seems to happen when I have rolled out > of the > throttle a little because the Kansas wind is strong enough to just > about coast. > It takes awhile for it to start to do it, but it continues to get > worse unless I > open the throttle or slow down more. This happens at about 65 to 70 > MPH. Does > anyone think it is possible that when it is almost coasting at about > half > throttle, with the wind, that the vacuum is shutting off the petcock > valve and > it is staving it of fuel? With a 40 MPH tail wind it wouldn't take > much > throttle to keep it running at 65 MPH. These conditions are the > only time that > it happens. I have never had the same problem with my other KLR but > it is > geared differently and I don't ride highway with it very much. Has > anyone else > had a problem like this? > > BigO

<><><><><><> <><><><><><> Larry, Bob, I don't think the petcock vacuum line will be subjected to any significant changes just because of wind. That gets it's vacuum from the intake stroke (piston going down) and a restriction from the carb throat. When the petcock vacuum is less, fuel delivery will be less too. But it would have to be a sustained decrease in vacuum for you to notice. An experiment you can make is to go for a ride. While moving along at maybe 4,000-5,000 rpm turn off the petcock. Count how long it takes for you to notice a change in engine performance. I bet you get at least a count of 20 and maybe more like 40. If the petcock diaphragm is leaking and you already have a fuel delivery issue then it could be much quicker than a count of 20 to see negative performance. That could, kind of, maybe signify a low fuel level in the float bowl. You can check fuel level with a short, clear tube put on the float bowl drain and held upwards along the side of the carb. Open the drain on the float bowl and with the engine running the fuel level will be shown in the clear tube. It should be +/- 1mm of the junction of the float bowl and carb body. You can also check for a torn petcock diaphragm by taking a ride on the bike. After a few miles do a little closed throttle deceleration and then stop the bike. Immediately remove the vacuum hose from the back of the petcock and see if it drips fuel or is wet/damp inside. It should be bone dry and anything else indicates a leaking diaphragm. You can also put a Mity-Vac on the back of the petcock and apply vacuum. Watch the clear hose from the Mity-Vac and if fuel moves into it the diaphragm is leaking. Repairs are a new diaphragm, convert to a manual petcock by either replacing the petcock with I believe a Raptor petcock or replace the back of the petcock with a solid gasket. I sell a blockoff plate setup that has been available for over a year. I did recently have a guy tell me he installed it and a high speed surge immediately went away. That is the first time I've heard that result. Best, Jeff Saline ABC # 4412 South Dakota Airmarshal Airheads Beemer Club www.airheads.org The Beautiful Black Hills of South Dakota 75 R90/6, 03 KLR650 . . ____________________________________________________________ 53 Year Old Mom Looks 33 The Stunning Results of Her Wrinkle Trick Has Botox Doctors Worried http://thirdpartyoffers.juno.com/TGL3141/4fbf948185ce617188dbst06vuc

This isn't the case with mine. When the engine cuts off with a strong crosswind, I can twist the throttle further open and it doesn't respond. When the wind goes away my engine responds like normal. It is happening when the gust of wind comes from the left. The tachometer doesn't change RPM, so I believe its a fuel issue. I have adjusted my air screw at 1.75 turns. Also, I removed the snorkle. -David ________________________________ From: Eric J Foster To: DSN_KLR650@yahoogroups.com Sent: Saturday, May 26, 2012 6:49 AM Subject: [DSN_KLR650] Re: High Winds and Coasting Issue Too lean a pilot setting? Tail wind lets him let off the throttle to the point a lean condition is being created at that rpm. E [Non-text portions of this message have been removed]

David, Is it possible something like the plastic choke attachment (or anything else) on the left side is badly cracked/broken/loose allowing forced air (high wind from the left) into the mixture? Randy Sent from my Verizon Wireless Phone -----Original Message----- From: David Nichols Sent: Tuesday, May 29, 2012 8:42 AM To: Eric J Foster ; DSN_KLR650@yahoogroups.com DSN_KLR650@yahoogroups.com> Subject: Re: [DSN_KLR650] Re: High Winds and Coasting Issue This isn't the case with mine. When the engine cuts off with a strong crosswind, I can twist the throttle further open and it doesn't respond. When the wind goes away my engine responds like normal. It is happening when the gust of wind comes from the left. The tachometer doesn't change RPM, so I believe its a fuel issue. I have adjusted my air screw at 1.75 turns. Also, I removed the snorkle. -David ________________________________ From: Eric J Foster To: DSN_KLR650@yahoogroups.com Sent: Saturday, May 26, 2012 6:49 AM Subject: [DSN_KLR650] Re: High Winds and Coasting Issue Too lean a pilot setting? Tail wind lets him let off the throttle to the point a lean condition is being created at that rpm. E [Non-text portions of this message have been removed] [The entire original message is not included] [Non-text portions of this message have been removed]

I have a Stead alloy choke fitting. The rubber boot is sealing it as well. Good thought, thanks. ________________________________ From: SniperOne To: KLR List DSN_KLR650@yahoogroups.com> Sent: Tuesday, May 29, 2012 1:34 PM Subject: [DSN_KLR650] High Winds and Coasting Issue David, Is it possible something like the plastic choke attachment (or anything else) on the left side is badly cracked/broken/loose allowing forced air (high wind from the left) into the mixture? Randy Sent from my Verizon Wireless Phone -----Original Message----- From: David Nichols Sent: Tuesday, May 29, 2012 8:42 AM To: Eric J Foster ; DSN_KLR650@yahoogroups.com DSN_KLR650@yahoogroups.com> Subject: Re: [DSN_KLR650] Re: High Winds and Coasting Issue This isn't the case with mine. When the engine cuts off with a strong crosswind, I can twist the throttle further open and it doesn't respond. When the wind goes away my engine responds like normal. It is happening when the gust of wind comes from the left. The tachometer doesn't change RPM, so I believe its a fuel issue. I have adjusted my air screw at 1.75 turns. Also, I removed the snorkle. -David ________________________________ From: Eric J Foster To: DSN_KLR650@yahoogroups.com Sent: Saturday, May 26, 2012 6:49 AM Subject: [DSN_KLR650] Re: High Winds and Coasting Issue Too lean a pilot setting? Tail wind lets him let off the throttle to the point a lean condition is being created at that rpm. E [Non-text portions of this message have been removed] [The entire original message is not included] [Non-text portions of this message have been removed] [Non-text portions of this message have been removed]

Is it possible the snorkle acts as a baffle to prevent overly lean conditions when the intake is subjected to wind pressure? eddie

> -----Original Message----- > From: David Nichols >(snip) Also, I removed the snorkle. > > -David >

The only other thing I can think of is if you've rerouted the carb vent line to the left side or done the T-mod and air pressure is pushing in the hose and messing with the carburation. I rerouted mine with the inlet behind my 09's starter relay cover. To keep critters out of the hose, I fitted a plastic lawn mower fuel filter on the end. The carb "breathes" perfectly with it in place. It's not often I encounter a strong crosswind of any duration. But, it's never lost power on me, either. eddie

> [Original Message] > From: eddie > Subject: Re: [DSN_KLR650] High Winds and Coasting Issue > > Is it possible the snorkle acts as a baffle to prevent overly lean > conditions when the intake is subjected to wind pressure? > eddie > > > -----Original Message----- > > From: David Nichols > >(snip) Also, I removed the snorkle. > > > > -David

My carb vent is routed down and the end of the tube is right next to the airbox drain just to the right of the rear shock linkage. No T mod has been done...yet. ________________________________ From: eddie To: KLR650 list DSN_KLR650@yahoogroups.com> Sent: Tuesday, May 29, 2012 1:58 PM Subject: Re: [DSN_KLR650] High Winds and Coasting Issue The only other thing I can think of is if you've rerouted the carb vent line to the left side or done the T-mod and air pressure is pushing in the hose and messing with the carburation. I rerouted mine with the inlet behind my 09's starter relay cover. To keep critters out of the hose, I fitted a plastic lawn mower fuel filter on the end. The carb "breathes" perfectly with it in place. It's not often I encounter a strong crosswind of any duration. But, it's never lost power on me, either. eddie

> [Original Message] > From: eddie > Subject: Re: [DSN_KLR650] High Winds and Coasting Issue > > Is it possible the snorkle acts as a baffle to prevent overly lean > conditions when the intake is subjected to wind pressure? > eddie > > > -----Original Message----- > > From: David Nichols > >(snip) Also, I removed the snorkle. > > > > -David

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In this picture, you can see the two hoses to the right of the kick stand. The longer one is the carb vent. I tried to make the engine stall by plugging it with my finger at idle and it ran for about 30 seconds before I gave up. I guess I could try plugging it longer but I think if it's air pressures affecting it at speed in a cross wind it would be a completely different scenario. I guess I need to get a leaf blower... Photo: http://i1248.photobucket.com/albums/hh482/nichodr/C360_2012-03-28-12-17-35.jpg ________________________________ From: eddie To: KLR650 list DSN_KLR650@yahoogroups.com> Sent: Tuesday, May 29, 2012 1:58 PM Subject: Re: [DSN_KLR650] High Winds and Coasting Issue The only other thing I can think of is if you've rerouted the carb vent line to the left side or done the T-mod and air pressure is pushing in the hose and messing with the carburation. I rerouted mine with the inlet behind my 09's starter relay cover. To keep critters out of the hose, I fitted a plastic lawn mower fuel filter on the end. The carb "breathes" perfectly with it in place. It's not often I encounter a strong crosswind of any duration. But, it's never lost power on me, either. eddie

> [Original Message] > From: eddie > Subject: Re: [DSN_KLR650] High Winds and Coasting Issue > > Is it possible the snorkle acts as a baffle to prevent overly lean > conditions when the intake is subjected to wind pressure? > eddie > > > -----Original Message----- > > From: David Nichols > >(snip) Also, I removed the snorkle. > > > > -David

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--- In DSN_KLR650@yahoogroups.com, SniperOne wrote:

> > Thanks Jeff. > I'll start at the cluster and work my way through each item until I find the issue. BTW, '00 year model. > Randy

There is the real problem: YTK. That bike is so ugly it repels being ridden. wink. revmaaatin. who wonders, 'who picks these colours'.