XJ650 Start up rev issue

k-moe · Apr 18, 2018

Did you let the bike fully warm up before blipping the throttle?

And MERGED.

Daniel Diblasi · Apr 18, 2018

XJ550H said: ↑

ok thanks for the history as well.
is your tank full or at least have 2 gallons of fuel in it? you have a 3.4 gallon tank with .8 gallon reserve
the second line is a vacuum line is it connected? it connects to the nipple on manifold boots. if it is not connected fuel will not flow.
test you petcock. fuel is gravity feed and not sucked into carbs.

turn petcock to prime and run fuel hose into a mason jar see if it flows well. or just see if the bike runs well on prime
then turn to on or reserve.
do you have a vacuum pump/bleeder if so apply vacuum to petcock vacuum port see if fuel flows from petcock in the on and reserve position

if you do not have a pump just attach a hose to vac port and suck on it fuel should flow

if i understand you correctly you are siphoning from tank to carbs. if this is the case I would look at the petcock and vacuum line there is also a vent in gascap that should be cleaned out but if this is happening on start up cap should not be the problem but clean it any ways. unlock it to break the seal
you could have a bad vacuum line replace it. size is 4mm id
Your Gas Cap and You
. if you have non vacuum petcock plug the vacuum line a cap on the nipple on manifold boot would be best.

you will need to rebuild or replace your petcock if it fails the above tests

will the bike run with out the pods and respond to throttle? could be you over modified them.

your bike is an XJ650 correct?
Click to expand...

Yes its an xj650 but i think the guy I bought it from put a xj750 tank on it. The vacuum line is connected to the manifold boots. I will test he petcock and gascap filter to see if that does anything.

Daniel Diblasi · Apr 18, 2018

k-moe said: ↑

Did you let the bike fully warm up before blipping the throttle?

And MERGED.
Click to expand...

yes

Daniel Diblasi · Apr 18, 2018

XJ550H said: ↑

in your other post you say "It started idling at about 1-2 for a little but realized the fuel was shut off." , do you have a manual petcock?

XJ650 Start up rev issue

moderators would you merge these threads for clarity?
Click to expand...

yes i have a manual petcock, i have a xj750 tank on a xj650.

XJ550H · Apr 19, 2018

Daniel Diblasi said: ↑

Yes its an xj650 but i think the guy I bought it from put a xj750 tank on it. The vacuum line is connected to the manifold boots. I will test he petcock and gascap filter to see if that does anything.
Click to expand...

you should put caps on the ports not run vac line from port to port. and by manual I mean not vacuum operated.
gas cap has a vent not a filter but clean it.
750 has 1.8 reserve tank you need to have 3 gallons (over 1.8) in there for to run on on.

k-moe · Apr 19, 2018

There's also about a quart of gas that sits below the petcock, and will never get drained unless you tip the tank over.

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XJ650 Start up rev issue

k-moe Pie, Bacon, Bourbon. Moderator Premium Member

Daniel Diblasi New Member

Daniel Diblasi New Member

Daniel Diblasi New Member

XJ550H Well-Known Member Premium Member

k-moe Pie, Bacon, Bourbon. Moderator Premium Member

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