Major back fire happening

I

imncrxtc

XS650 Enthusiast
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Boys, last year before i parked the xs650 for the winter (Toronto), the bike ran fine. I didn't use any additives in the gas. This season after my bar and tank change/swap (i dont think this is related), i went to start it and it has trouble staying on when the choke is closed, and it back fires like a mother father. Any idea what it can be? Any suggestion will be greatly appreciated.
Thanks
 
My money's on the carbs. That gasohol was giving me constant problems (after extended pauses between riding), until I started using the 'treatments'.

Clean/check/set the points (if equipped) couldn't hurt...
 
imncrxtc said:
Do you guys think that carb cleaner in a bottle works?
Click to expand...

Hey imncrxtc, I'm up in Maple; Don't see too many other XS650s up here. Everytime I've watched someone clean carbs it's with an aerosol type can. You can pick up a can at Crappy Tire in the automotive section. Just don't ask any questions because the staff will drive you nuts.
 
I have had good results with SeaFoam, but if your carbs are really gunked up they will need a good manual cleaning first.
 
uhlaf...let me know if you want to get together, id love to see your bike...
as for the carbs, how much should i expect to pay from a bike shop?

and they arent gummed up, i mean the bike was running find last season.
 
imncrxtc said:
Boys, last year before i parked the xs650 for the winter (Toronto), the bike ran fine. I didn't use any additives in the gas. This season after my bar and tank change/swap (i dont think this is related), i went to start it and it has trouble staying on when the choke is closed, and it back fires like a mother father. Any idea what it can be? Any suggestion will be greatly appreciated.
Thanks
Click to expand...

I'd say your problem has come from doing the tank swap. If the tank (was it a used tank?)had rust or sediment of any type in it, that crap is now in your carbs, and may have partially plugged up the pilot jets.

Don't send your carbs to a shop. This is your chance to learn about how carbs work. There is a good info about carbs in the Tech section.
 
I'm a young guy who's had his bike a grand total of 2 weeks. I'm still fiddling around trying to get her in a condition where the mechanic won't sigh and shake his head, she's nothing special.

It's unlikely that the carbs are gummed up but after the last crazy winter a couple of other things may have happened, especially if your bike was stored in a non-heated garage or dare I say "outside". I had problems back firing through the carbs and I found that my vacuum wasn't plugged into my LH carb barb. It also explained why I had to run the bike on perma-prime. Go figures.

As for bike mechanics there are only a couple I would bother going to with this vintage, one is a crazy genius in brampton who you can contact on the GTAmotorcycle forums, everyone swears by him, goes by the handle "frekeyguy". He quoted picking up and dropping off my bike 60$ one way which is not bad at all. The second is Rosey Toes down by Weston and 400, you'll have to get your bike there by yourself but I've heard nothing but great things, a little rough around the edges though, but no bull. I plan on taking my bike to Rosey to have a quick once over and safety some time this week. I can't imagine a carb job being crazy expensive.

Reviews here: http://www.gtamotorcycle.com/vbforum/forumdisplay.php?20-Reviews
 
I know rosey toes, il check him out....BUT
you have peaked my interest, my bike has always run on PRIME,
but after you mentioned the vacuum, i remember when i was hooking up the new (used) gas tank, there was a vacuum hose which i had no idea where it came from, so i plugged it into the only area i deemed proper...i may be wrong, can you send me a pic of your left side carb/tank area? Or i can drop by one of these evening and have a look, or if you have a minute, maybe you can drop by to have a look.
 
Let me get home. I'll describe it first and get some pictures going when I'm back from work.

Look at your left hand carb and follow it to your engine, there should be a 1/8th inch metal barb coming out if the carb boot RIGHT before the engine. If you look on the right hand side you'll see the barb is blocked off with a rubber dome and a clip. So that's a huge vaccum leak that's sucking air into the mix on the left hand side. What should be on the open barb is the vacuum hose from your petcock, don't forget to turn it off prime.

Alternatively you could do what I had done a block the barb with something and use good ole gravity.

Send me a PM, maybe we can help each other out in this cruel reality of vintage bikes
 
Here ve zee de barb in it's free and naked stake, please note the location close to the engine.
ae4js2.jpg


And here we see the barb all friendly with the petcock. Note the large tube running from the barb to the back of the petcock
29xtf02.jpg


And here we see the lonely barb on the right side, capped and bound.
2eclons.jpg


PAY NO ATTENTION TO THE GIANT LEAKS IN THE BOOTS
 

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