Bats62 Posted November 11, 2022 Share Posted November 11, 2022 Hi. She starts easily with no issues and rum perfectly initially. When a bit warmer the engine starts to sound a feel lumpy as if trying stall but just picks up at the last minute. Always been serviced changed the plugs twice to see if it helped. Could the cold start mechanism be faulty (feels like choke sticking ) dont even know what or how to change it if needed. Any help will be greatly appreciated thank you in advance Bats 62 Quote Link to comment Share on other sites More sharing options...
XXitanium Posted November 12, 2022 Share Posted November 12, 2022 What model year please? Pre1999 is carb, 1999 and after is Fuel Injected. Are there any noises along with it? 6 hours ago, Bats62 said: Any help will be greatly appreciated Quote Link to comment Share on other sites More sharing options...
Bats62 Posted November 12, 2022 Author Share Posted November 12, 2022 Hi it’s a 2007 so fuel injected 16000 miles Quote Link to comment Share on other sites More sharing options...
fizzy Posted November 12, 2022 Share Posted November 12, 2022 Could be a charging problem. What is the running voltage? Should be 13V (or a little more) at idle to 14.5V when revved. Quote Link to comment Share on other sites More sharing options...
Bats62 Posted November 12, 2022 Author Share Posted November 12, 2022 Never thought of that thanks Quote Link to comment Share on other sites More sharing options...
ironmike Posted November 12, 2022 Share Posted November 12, 2022 If the charging system is okay (good battery, etc.) and the symptoms persist, check out the fuel pressure regulator (FPR). Lift the tank, pull the vent lines, and look for raw fuel in those lines--even a trace is an indication of a compromised FPR diaphragm (a pinhole can do it). If that's the case, it'll only get worse--replace the FPR. That job is neither difficult nor too expensive. 1 Quote Link to comment Share on other sites More sharing options...
superhawk996 Posted November 14, 2022 Share Posted November 14, 2022 My first thought was FPR as mentioned, or maybe a bad O2 sensor. I don't know how much the O2 can mess with these, but because the sensor only starts working once warmed up it made me think of that possibility. I've had several experiences with cars where a bad O2 won't throw a code but will mess with the fueling a lot. Quote Link to comment Share on other sites More sharing options...
superhawk996 Posted November 14, 2022 Share Posted November 14, 2022 As far as I know, the cold start mechanism only holds the throttle open and doesn't change fueling so I don't think it's that. If it was sticking in the cold position I'd just expect a high idle. Quote Link to comment Share on other sites More sharing options...
tomek Posted November 14, 2022 Share Posted November 14, 2022 11 hours ago, superhawk996 said: My first thought was FPR as mentioned, or maybe a bad O2 sensor. I don't know how much the O2 can mess with these, but because the sensor only starts working once warmed up it made me think of that possibility. I've had several experiences with cars where a bad O2 won't throw a code but will mess with the fueling a lot. O2 doesn't do shit at idle. Cold or warm. At least not on anything made in 2007. Quote Link to comment Share on other sites More sharing options...
tomek Posted November 14, 2022 Share Posted November 14, 2022 11 hours ago, superhawk996 said: As far as I know, the cold start mechanism only holds the throttle open and doesn't change fueling so I don't think it's that. If it was sticking in the cold position I'd just expect a high idle. Wrong again. Cold start mechanism won't do shit with the throttle. It opens bypass circuit. What rpm is engine spinning when it happens? Quote Link to comment Share on other sites More sharing options...
tomek Posted November 14, 2022 Share Posted November 14, 2022 (edited) Perhaps something as simple as idle speed adjusted too low, that's why I asked. Cold start mechanism. That thing by #3, with pushrod sticking out. You may wanna remove it and clean it very well. Btw, "7" is idle speed adjustment cable. Edited November 14, 2022 by tomek Quote Link to comment Share on other sites More sharing options...
superhawk996 Posted November 14, 2022 Share Posted November 14, 2022 46 minutes ago, tomek said: O2 doesn't do shit at idle. Cold or warm. At least not on anything made in 2007. False, it does on cars/trucks from decades ago to today, but I've never checked to see if it does on bikes. 44 minutes ago, tomek said: Wrong again. Cold start mechanism won't do shit with the throttle. It opens bypass circuit. I was simplifying what it does by saying "throttle", there's no need to cunty. Another possibility is the engine coolant temp sensor, if it's stuck reading low it could make the bike run rich when warm. When they fail they usually fail so badly that it throws a fault code, but not always. Another possibility is corrosion in the 'test connector'. If you search "loom fix" it should show details on that. Quote Link to comment Share on other sites More sharing options...
tomek Posted November 14, 2022 Share Posted November 14, 2022 3 hours ago, superhawk996 said: False, it does on cars/trucks from decades ago to today, but I've never checked to see if it does on bikes. I was simplifying what it does by saying "throttle", there's no need to cunty. Another possibility is the engine coolant temp sensor, if it's stuck reading low it could make the bike run rich when warm. When they fail they usually fail so badly that it throws a fault code, but not always. Another possibility is corrosion in the 'test connector'. If you search "loom fix" it should show details on that. Wut? This motorcycle, not car. Narrow band O2, can't control mixture at idle, because it needs to be on relatively rich side. Quote Link to comment Share on other sites More sharing options...
XXitanium Posted November 14, 2022 Share Posted November 14, 2022 Quote Link to comment Share on other sites More sharing options...
superhawk996 Posted November 15, 2022 Share Posted November 15, 2022 7 hours ago, tomek said: Wut? This motorcycle, not car. Narrow band O2, can't control mixture at idle, because it needs to be on relatively rich side. Narrow band O2s on cars/trucks do control the idle mixture and have since WAY back. Whether the bike's ECU uses them at idle I don't know. Quote Link to comment Share on other sites More sharing options...
ptxyz Posted November 16, 2022 Share Posted November 16, 2022 does the temperature sensor also feed information to the digital guage? in other words, there's only 1, correct? apologies to the o.p. for piggybacking... my bird's always gotten horrible fuel mileage unless i'm riding like a granny... Quote Link to comment Share on other sites More sharing options...
fizzy Posted November 16, 2022 Share Posted November 16, 2022 1 hour ago, ptxyz said: does the temperature sensor also feed information to the digital guage? in other words, there's only 1, correct? apologies to the o.p. for piggybacking... my bird's always gotten horrible fuel mileage unless i'm riding like a granny... Hopefully, bats62 returns with an update. In the meantime, how horrible? Assume no dragging brakes, slipping clutch, silly rear sprocket, totally clogger air filter, etc. Check the FPR for a pinhole leak. Pull the vac line where it connects to the FPR after a brief (or long) start/stop. Vac line must be DRY. Note: I think there are 2 temp sensors. One sends info to the ECU, this controls the fan. Other does the gauge (Digital dash model). Quote Link to comment Share on other sites More sharing options...
ptxyz Posted November 17, 2022 Share Posted November 17, 2022 25-30 mpg on my regular commute, with full throttle pulls getting onto the freeway, traffic permitting. low 40's when riding sedately in a group on the highways. been like this for several years. been awhile since i checked the fpr, which i upgraded a few years back. fan comes on around at around 220 degrees. know the part# for the ecu temp sensor? Quote Link to comment Share on other sites More sharing options...
SwampNut Posted November 17, 2022 Share Posted November 17, 2022 20 minutes ago, ptxyz said: 25-30 mpg on my regular commute, with full throttle pulls getting onto the freeway, traffic permitting. low 40's when riding sedately in a group on the highways. been like this for several years. That is fucked. I had to try hard to get under 40. The only time I saw 25-ish was doing a top speed run for something like 15 minutes, then 145 for a while longer. I can't remember whether the XX has an air temp sensor in the airbox too, and what that could do if it was bad. Quote Link to comment Share on other sites More sharing options...
TFT Posted November 18, 2022 Share Posted November 18, 2022 5 hours ago, ptxyz said: 25-30 mpg on my regular commute, with full throttle pulls getting onto the freeway, traffic permitting. low 40's when riding sedately in a group on the highways. been like this for several years. 5 hours ago, SwampNut said: That is fucked. I had to try hard to get under 40. The only time I saw 25-ish was doing a top speed run for something like 15 minutes, then 145 for a while longer. My 1997 Alaska XX (now my AZ XX) never got close to 40, 36 tops. The carbs have a jet kit in them so that may be the reason. Quote Link to comment Share on other sites More sharing options...
XXitanium Posted November 18, 2022 Share Posted November 18, 2022 I get just above 35mpg pretty much all around? Quote Link to comment Share on other sites More sharing options...
blackhawkxx Posted November 18, 2022 Share Posted November 18, 2022 7 hours ago, ptxyz said: 25-30 mpg on my regular commute, with full throttle pulls getting onto the freeway, traffic permitting. low 40's when riding sedately in a group on the highways. been like this for several years. been awhile since i checked the fpr, which i upgraded a few years back. fan comes on around at around 220 degrees. know the part# for the ecu temp sensor? Have you changed you gearing? Quote Link to comment Share on other sites More sharing options...
fizzy Posted November 18, 2022 Share Posted November 18, 2022 8 hours ago, ptxyz said: 25-30 mpg on my regular commute, with full throttle pulls getting onto the freeway, traffic permitting. low 40's when riding sedately in a group on the highways. been like this for several years. been awhile since i checked the fpr, which i upgraded a few years back. fan comes on around at around 220 degrees. know the part# for the ecu temp sensor? " fpr, which i upgraded" upgraded? Quote Link to comment Share on other sites More sharing options...
SwampNut Posted November 18, 2022 Share Posted November 18, 2022 4 hours ago, TFT said: The carbs have a jet kit in them so that may be the reason. Carbs blow syphillitic donkeys. Quote Link to comment Share on other sites More sharing options...
blackhawkxx Posted November 18, 2022 Share Posted November 18, 2022 6 hours ago, SwampNut said: Carbs never turn on check engine lights. FTFY Quote Link to comment Share on other sites More sharing options...
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