Won't Start

sickle44 · Post by **sickle44** » Sat Jul 04, 2009 7:20 pm

Hey Fellas(Fellettes)

Perhaps some of you have been plaqued with the same issues from the same old XJ 750 Seca as I have. I'm fixing one for a friend and for the life of me the damned machine will not start whatsoever. All I can get it to do is backfire for me the odd time. I've got spark at each plug, I've got fuel in the tank, petcock is on, and travelling down to carbs, float bowls are being fed and full. Now from float bowl to cylinder, something shits the bed. Carbs have been cleaned several times now and air comes out of the other end of every orifice I've cleaned on the damned carbs. Aside from little friggen 1/2 inch tall gas eating alien monsters sucking up fuel in the intake tract, I am clueless and fed up.

A little help, anybody?

Post by **FZRDude** » Sat Jul 04, 2009 7:27 pm

You didn't mention compression readings. Do you smell fuel in the cylinders? Use a turkey baster to suck some air out of the cyl through the plug hole and squirt it in you face gently.

That's about all the help I can provide.

sickle44 · Post by **sickle44** » Sun Jul 05, 2009 3:37 am

sorry compression is good across the board although a little lower in 1 and 2 but within spec

Yoniboi · Post by **Yoniboi** » Sun Jul 05, 2009 3:51 am

Timing out.....????

J

creed12r · Post by **creed12r** » Sun Jul 05, 2009 9:50 am

Coils connected up the wrong way around?

1 and 4 coil going to 2 and 3 plug and visa versa

sickle44 · Post by **sickle44** » Sun Jul 05, 2009 1:24 pm

Timing - Good
Coils and wire connections, Good

Not getting fuel from float bowl to cylinder, that's the real issue.

Outlaw · Post by **Outlaw** » Sun Jul 05, 2009 5:25 pm

sickle44 wrote: Not getting fuel from float bowl to cylinder, that's the real issue.

So you've tried priming it, and it starts that way? (for a few seconds)

I had an 88 FZR1000 that wouldn't start unless you pointed a torpedo heater
at the motor for about a half an hour before you tried to start it...
Turned out to be the valves were badly out of adjustment..... just a thought.

hmmmm ... on second thought, that would screw up the compression readings, wouldn't it.... nevermind....

...

sickle44 · Post by **sickle44** » Sun Jul 05, 2009 11:59 pm

Valve job had fixed the previous non-starting issue, however, I think I might have stumbled upon the errors through pouring over threads for xjBikes.

Float levels were out from 2 - 4 mm across the board due to incorrect measurment of where the beginning point for measuring began. The wide variance is due to the fact that it's an old machine and non of the floats are the same by any means, then again, I guess no floats really are?

Secondly, the butterflies were right friggen closed off, not to good if you'd like to pass an air/fuel mixture by them I suppose. DOOOohhhh

Suppose that's my own fault for having stayed up for 48hours straight to work on it.

Well not sure if these issues are all just yet, but I sure am hoping so. I'll get the carbs back in tomorrow and see then, here's hopin'

ace of spades · Post by **ace of spades** » Mon Jul 06, 2009 11:20 pm

Aside from little friggen 1/2 inch tall gas eating alien monsters sucking up fuel in the intake tract, I am clueless and fed up.

:ha

Know the feeling. My Fizzer is also struggling to start. Eventually, after cleaning and checking everything fifty or sixty times over, I think I might have found the probs: The Carb boots. There are some slight cracks on them. I don't know, will see when I change them. Don't get me wrong, the bike starts, but only after cursing that sounds worse than the Boondock Saints'.

Hope you are good on the starting

hotcam · Post by **hotcam** » Mon Jul 06, 2009 11:59 pm

How fresh is the fuel in the tank? If it's more than a week old, i'd be
changing it. Otherwise, yes air getting in past the carb boots
and leaning things out is definitely possible too, like Ace said.

sickle44 · Post by **sickle44** » Tue Jul 07, 2009 11:03 am

both good suggestions Cam, but Nope n' nope. Fuel's brand new and was changed the minute I was having issues. Boots, while beat to hell looking they are, surprisingly enough, they are good.

I believe I may have found the errors as I was sayin' earlier the butterflies were completely closed off and the float levels were out to lunch.

hotcam · Post by **hotcam** » Tue Jul 07, 2009 6:11 pm

Float levels will make a difference I agree.

I am surprised that the closed butterflies make a big difference as I
would have expected these carbs to have bypass jets for idle
which feed a minimal amount of air and fuel past the butterflies
when the throttle is off.

Then again, I sync'd my carbs 20,000km ago by using the thinnest
feeler gauge I had, and sticking it under the butterflies. I just re-sync'ed
with mercury tubes and it's all perfect. So maybe a .02mm gap is
a big difference to idling.

Good luck with them!

sickle44 · Post by **sickle44** » Wed Jul 08, 2009 12:35 am

They do have the by-pass thingy Cam but you still need some form of air getting by, or through the butterflys, otherwise, in theory, all you're really running on is fuel which of course is not possible. If the butterflies are completely sealed, all your left with is a vacuum and no fresh air coming in, someone correct me if I'm wrong.

I got her started now, now I've just get to fine tune it. JOy!!

hotcam · Post by **hotcam** » Wed Jul 08, 2009 2:36 am

I guess I'm used to the Keihins like on Kawasakis (had 4 bikes
with those), they have a seperate bypass circuit for air as well as
one for fuel.

got her started now

Excellent!

EXUP Worldwide

Won't Start

Won't Start

coils