Having trouble with new FX250 SSR

[Desert Rider]

What’s up everyone I read a little through the forums and thought this would be the best place to post about my troubles. The bike only has about 570 km and I will be doing the first oil change soon but I let the bike sit for a while with gas from last seasons camping and trying to get it started again. It is not my daily and I didn’t realize I should’ve properly stored it away. so recently in the last week or so I started working on getting it started I drained all the fuel and cleaned the carb, also changed the battery to get it started much better. So an hour ago I tried to run it, started with the full choke to get it a little warmed up, went half and later no choke, once it’s idling it’s sitting around 2000rpm but feels choppy? So I go to pull the throttle lightly and shuts off instantly, I try again with the throttle pulled back fast, shuts off again, so I let it idle a little bit longer and tried to slowly pull the throttle 1mm at a time and rpms finally went up but very choppy and weird again so I pulled throttle even further and rpms went up but very delayed and died again. ( I didn’t let it go above 5000 rpm as per the manual for before 600 km 1000km mark) so I’m wondering if I didn’t clean the carb well enough? Or what can I trouble shoot next. Note I am very new and willing to learn more about my bike and would love to learn to fix my self. Could I have put too much carb cleaner in the carb? Idk what to trouble shoot next any help would be appreciated

[Megadan]

How in depth was the carb cleaning? If the carb was varnished up enough it may need to be soaked/boiled/ultrasonic cleaned and then some air blown through every orifice to get any stuck varnish/crud out of the small air and fuel passages.

[culcune]

What desert are you in? Member dh has an XF250 and lives in the high desert above the inland empire of the greater metro Los Angeles area. You guys could compare notes down the road, but as far as the carb issue--Megadan has given you a place to start.

[paulsstag]

Originally Posted by Desert Rider

What’s up everyone I read a little through the forums and thought this would be the best place to post about my troubles. The bike only has about 570 km and I will be doing the first oil change soon but I let the bike sit for a while with gas from last seasons camping and trying to get it started again. It is not my daily and I didn’t realize I should’ve properly stored it away. so recently in the last week or so I started working on getting it started I drained all the fuel and cleaned the carb, also changed the battery to get it started much better. So an hour ago I tried to run it, started with the full choke to get it a little warmed up, went half and later no choke, once it’s idling it’s sitting around 2000rpm but feels choppy? So I go to pull the throttle lightly and shuts off instantly, I try again with the throttle pulled back fast, shuts off again, so I let it idle a little bit longer and tried to slowly pull the throttle 1mm at a time and rpms finally went up but very choppy and weird again so I pulled throttle even further and rpms went up but very delayed and died again. ( I didn’t let it go above 5000 rpm as per the manual for before 600 km 1000km mark) so I’m wondering if I didn’t clean the carb well enough? Or what can I trouble shoot next. Note I am very new and willing to learn more about my bike and would love to learn to fix my self. Could I have put too much carb cleaner in the carb? Idk what to trouble shoot next any help would be appreciated

So today, after working graveyard shifts i decided to try a different jet in my new carb (vm26 mikuni clone). I pulled the carb from its mount and put in a 108 main jet (was 105). Reassembled the bike and now had the exact conditions you've got ??? WTF i only changed one thing??. tried adjusting the air fuel screw etc ,no go. Eventually i pull the whole card assy off and put it on the bench thinking maybe i broke the tip of the air mixture screw in the carb body as adjusting it made no difference. I,m such a dumb ass i was puting it on full choke when i thought i was turning it off I put the carb back together and she is running great. I'm embarrassed to say but i've been working on bikes for a very long time with lots of carb experience but the proof is right there that it is the simple stuff that gets you.

So pull off the carb intake boot and make sure the choke is off and you have fuel flowing to the carb

If its not that we can go back over the carb issue.

[dh]

Hi DesertRider and welcome! This carb works a bit differently than the Mikuni. It's a CV carb and it works using vacuum pressure. I don't know if you live in the desert or just frequently ride there, but we experience extreme cold and extreme heat. In the Mojave desert, temps in an uninsulated garage or shed can reach close to 200 degrees. This style of carb is sensitive to changes in air pressure and temperature. If you parked the bike after a cold winter day and you wait a few months to start it again after marinating in the hot garage, you will experience some difficulty starting which make one think a carb cleaning is in order.... Given my experience with this particular carb and the age of your bike, I doubt your bike needed serious carb cleaning to begin with but it is possible.

1. Did you fully disassemble during cleaning? If so I suspect you have a reassembly issue relating to the rubber vacuum diaphragm and cap or needle/spring. The rubber diaphragm should be reinstalled clean, dry, and not pinched or folded. It is a delicate part and if you sprayed it with carb cleaner it might be warped or stretched which would make it difficult to seat properly.

2. There is a reed valve/egr device on the exhaust header to make the bike run lean and pass emmissions- make sure the hose coming off of that is not blackened or crunchy which would indicate the valve is bad and you have hot exhaust being pumped into your airbox. FYI This valve sucks and needs to go in the trash and you need to plug the hole. It will fail soon if it hasn't already.

3. Check for air in fuel lines, fuel in vacuum lines or just try and ride the bike and clear any of that out. If you added an aftermarket fuel filter it might be bad.

4. Make sure your airbox boot is still attached to the carb. My stock airbox liked to separate from the carb occasionally.

[dh]

Fuel sipping carbs, vacuum lines and EGR's... I gave myself flashbacks to the less enjoyable aspects of owning 1980's ford trucks. I wish I could buy my Bronco back though.