HELP!!! What do I do know? I am stuck.

[XS400D]

So I put my bike back together yesterday after replacing the battery, draining the tank, changing the oil and filter, cleaning the carbs and putting some cleaner in the fuel. I tried to start it up and no luck although it was a cold day so i was not too bothered.

So today, I tried again and its getting close but the idle was thumpy and wouldn't hold past a few seconds. It seems like the right cylinder has better compression but I do get pressure out of the left exhaust. I am also seeing some kind of light smoke coming from the crankcase breather filter. WHY WON'T MY BIKE START!?!?!?

-Taylor

 

[XS400D]

no one has any advice =(

 

[drewpy]

try servicing the bike; timing, adjust valves check for sparks.

check compression if you feel that is an issue.

having a "thumpy" bike is not a lot of info to diagnose

 

[HoughMade]

Hate to say this, but I would venture you only think your carbs are clean. I had mine off and disassembled about 5 times before they were clean enough to run right.

 

[XS400D]

Hate to say this, but I would venture you only think your carbs are clean. I had mine off and disassembled about 5 times before they were clean enough to run right.

sadly that is what i am worried of... it seems there is a little bit of fuel leaking from the left carb out the filter end and now for the first time it seems there are small drips coming from the petcock. since the left is the side it leans on that was the dirtier carb when i cleaned them. i was able to run a carb cleaning wire through all of the jets and crevaces but perhaps i need to boil them.

 

[XS400D]

try servicing the bike; timing, adjust valves check for sparks.

check compression if you feel that is an issue.

having a "thumpy" bike is not a lot of info to diagnose

I know thumpy is a poor word choice. The bike ran well til I let the battery die last winter which I then let the carbs get gummy. Would sitting around really be enough to mess up the timing?

 

[drewpy]

really need to service the bike to eliminateany of those issues. then you can start on those carbs

 

[dabearded1]

the bike im working on wouldn't run when we got it. Carbs were relatively clean but I cleaned them anyway. Bike still would not run. I checked the static timing and the left side was way off. I set it and it fired right up. Bike was last inspected in 2001/2002, p.o. said he had it for 2 years and couldn't get it running. I also drained the tank and put fresh gas in it.

After you get the fuel leak fixed make sure you have spark on both sides. Locate the video on this forum for setting static timing and give it a check. HTH. Best of luck

 

[XS400D]

the bike im working on wouldn't run when we got it. Carbs were relatively clean but I cleaned them anyway. Bike still would not run. I checked the static timing and the left side was way off. I set it and it fired right up. Bike was last inspected in 2001/2002, p.o. said he had it for 2 years and couldn't get it running. I also drained the tank and put fresh gas in it.

After you get the fuel leak fixed make sure you have spark on both sides. Locate the video on this forum for setting static timing and give it a check. HTH. Best of luck

i just watched the video and it seems easy enough to do that it wont hurt. do i need to drain the oil before timing? the only reason i am unsure of it being the timing is that i had the bike running well from the PO

 

[dabearded1]

No you do not have to drain the oil. Some may spill out from the points cover but it shouldn't be much. These bikes use a points system that's almost identical to classis cars. Doesn't take much for it the points to move. P.o. could have set them and not tightened the screws enough. It's worth a check and it only takes maybe 5-10 minutes. Have you checked the air boxes for a rodents nest? Spark plugs could be bad as well.

 

[XS400D]

No you do not have to drain the oil. Some may spill out from the points cover but it shouldn't be much. These bikes use a points system that's almost identical to classis cars. Doesn't take much for it the points to move. P.o. could have set them and not tightened the screws enough. It's worth a check and it only takes maybe 5-10 minutes. Have you checked the air boxes for a rodents nest? Spark plugs could be bad as well.

Pulled the carbs the other day which have uni pods so no worries on the air boxes. Plugs was the next thing to check. Unfortunately I don't get to spend long spans of time working on the bike just handfuls of time here and there, that's why the guidance form the forum is greatly appreciated. Hopefully after work today I can take some time to check the plugs and points.

 

[XS400D]

Soooooo.... Weird update, tried again to start the bike today, i noticed fule leaking form the left carb and out the air intake at the filter as well as fuel on the left fins. I decided to disconect the fuel line from the carb and let some excess fuel drain out and then tried to start the bike with the fuel line disconnected and lo and behold THE BIKE STARTED UP! so I hooked the fuel back up and it ran for like 4-5 minutes and then when i reved the engine it died out again

 

[hmusket]

Seems like running too rich to the point of flooding. Pull the carbs, check the float levels, should be 26mm. If I remember correctly 32mm is incorrect. Also, check your float needles and seating for any debris.

 

[XS400D]

Seems like running too rich to the point of flooding. Pull the carbs, check the float levels, should be 26mm. If I remember correctly 32mm is incorrect. Also, check your float needles and seating for any debris.

I checked the needles and the float height. 26mm and the needles looked good but I didn't have something to look at them closely with. Has anyone ever done different float heights?

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[hmusket]

Check out the threads by a member by the name of Bcware. He did a lot of work on getting his bike, which may be the same model as yours, tuned and going, he focused on carbs. If you haven't changed the plugs, I would probably try that, along with new plug wiring, (solid core non resistor), and new caps, you want to get as much spark as possible. Recharge your battery if you haven't done that.