CB650 Spark Splug Problem PLZ HELP

If it's broken or just needs tweaked

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WiseTurtle
Posts: 39
Joined: Wed Aug 17, 2016 2:06 am
Location: California :(

Re: CB650 Spark Splug Problem PLZ HELP

Postby WiseTurtle » Sat Apr 07, 2018 10:33 am

The fuel filter is my doing. I just put that pic to show how I routed the gas line in order to fit in there, as its almost horizontal.

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WiseTurtle
Posts: 39
Joined: Wed Aug 17, 2016 2:06 am
Location: California :(

Re: CB650 Spark Splug Problem PLZ HELP

Postby WiseTurtle » Sun Apr 08, 2018 12:19 pm

Hows my needle?
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IMG_7774.JPG (1.04 MiB) Viewed 1019 times

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GeorgeSweety
Posts: 323
Joined: Tue Aug 08, 2017 11:47 am
Location: UK.

Re: CB650 Spark Splug Problem PLZ HELP

Postby GeorgeSweety » Sun Apr 08, 2018 1:27 pm

Hi WT, I can't really tell from that picture if there's a washer in there or not, but if there is then it shouldn't be. If your other three needles look ok then that one dented / chipped needle isn't gonna cause your other 3 plugs to foul up. I had one needle that had been damaged and filed sort of back into shape by a PO and I just could not get that carb to sync the same as the others until I changed the needle.
Have you always had this same rich running problem with this bike while you have owned it?
Can I suggest at this point, if you haven't already then invest in a set of JIS (Japanese Industrial Screwdrivers) if you want to keep your screw heads good and keen, once in the cross head they will not move or slip (unless a butcher has already been at them with a Phillips).

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WiseTurtle
Posts: 39
Joined: Wed Aug 17, 2016 2:06 am
Location: California :(

Re: CB650 Spark Splug Problem PLZ HELP

Postby WiseTurtle » Sun Apr 08, 2018 2:08 pm

Good news, I was able to seperate the slide from the arm and needle and there was no washer but only a circular horsehoe washer attached to the needle and no grooves to adjust the needle height (non adjustable). The bad news, I destroyed that big philips screw so i need to go get the another metric from my local hardware store. So the needles I got with my carb kits would have been wrong anyway. After I replace this screw and put the carbs back on Im going to try the bike with the new float heights I set for 2,3,4 and see how it goes. The height is similar to #1 which is lean and within spec.

I didnt take any pics since I didnt want to touch my phone with oily hands but it looks exactly like this

https://www.ebay.ca/itm/CARBURETOR-LEFT ... Wx&vxp=mtr

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GeorgeSweety
Posts: 323
Joined: Tue Aug 08, 2017 11:47 am
Location: UK.

Re: CB650 Spark Splug Problem PLZ HELP

Postby GeorgeSweety » Sun Apr 08, 2018 2:32 pm

WiseTurtle wrote:Good news, I was able to seperate the slide from the arm and needle and there was no washer but only a circular horsehoe washer attached to the needle and no grooves to adjust the needle height (non adjustable). The bad news, I destroyed that big philips screw so i need to go get the another metric from my local hardware store. So the needles I got with my carb kits would have been wrong anyway. After I replace this screw and put the carbs back on Im going to try the bike with the new float heights I set for 2,3,4 and see how it goes. The height is similar to #1 which is lean and within spec.

I didnt take any pics since I didnt want to touch my phone with oily hands but it looks exactly like this

https://www.ebay.ca/itm/CARBURETOR-LEFT ... Wx&vxp=mtr


Did you actually read the Item Description in the link? :lol: :lol: :lol:

"YES, I TAKE. YES, THESE PARTS ARE USED AND NOT SHOW QUALITY."

wtf? :roll:

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WiseTurtle
Posts: 39
Joined: Wed Aug 17, 2016 2:06 am
Location: California :(

Re: CB650 Spark Splug Problem PLZ HELP

Postby WiseTurtle » Tue Apr 10, 2018 7:14 pm

Finally got around to starting up the bike and that thing revved like crazy. It started out at 2000rpm then rose fast to over 5k and had to readjust the idle screw to quite a bit. One things for sure is it definitely feels lean because it got pretty hot fast. The acceleration was nice and even with no stuttering and I was able to rev high past 6-7k without any resistance or surging. The floats for 2,3,4 were readjusted for the 12.5mm height and looked like they were level with the #1 float which is lean. After different throttle positions and riding for about 8miles :( the plug for #4 was fouled but not as sooty as before. All the carbon wiped off with a paper towel, even the insulator which I could never get clean before. #1 looks good still and I havent checked the other 2 yet cause I have yet to remove the tank.

#1 Plug still looks great
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If the other plugs are still fouled then Im going to look at replacing the cables and caps.

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WiseTurtle
Posts: 39
Joined: Wed Aug 17, 2016 2:06 am
Location: California :(

Re: CB650 Spark Splug Problem PLZ HELP

Postby WiseTurtle » Mon May 21, 2018 11:27 pm

SOLVED!!!!!!!!!!!!!!!!!!!!!
Air cutoff valves on 2,3,4 carbs were toast and just replaced them all for only $30. The only good one was on the #1 cylinder which is why it was lean. All is good now and no more black plugs. :mrgreen:


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