Running rough...

[Norway Max]

Hello guys!

I've finally put my 88 MAX back together, and it's been running good since i calibrated the carbs. Yesterday i was out riding, after a hard accellereration, it started to sputter. I drove it back home, and found that i didn't run on the aft cylinder on the right side. Did the "shotgun" and it's back running on all four on idle and up to about 2000 rpm's. But when i drive it, it starts to stutter and run like crap. Once the V-boost kicks in in runs like hell, but from about 2000 and up to 6000 i can hear that one cylinder isn't firing... Any ideas? Rebuild carbs..? Shotgun once more..??

Thanks in advance,
Norway MAX

 

[Rhoy Carter]

Sounds like you have the low speed idle circuit plugged

 

[DMAN999]

Have you checked the Diaphram and needle alignment on that carb ?

 

[The Beekeeper]

I would do the shotgun again before you tear into the carbs, I flush them a couple of good times each when I do it...................Tom.

 

[Norway Max]

Thank you guys.

The Diaphram and needle alignment looks ok.
One more thing i have noticed, is that it's sounds louder in a way... Like the engine is running harder... Difficult to explain, but it's like a harder sound of the engine.... I don't know... :ummm:

Anyway, i'll try to do the shotgun routine again tomorrow and see.

 

[Norway Max]

New day, new possibilities...

Tried the "shotgun" again today with carbcleaner. Started up, and it runs smoth and nice on idle. Syncro on the carbs are dead on. But... When i start driving it, it starts to sputter and it clearly runs on only three cylinders all the way up to 6000 rpm's. Then it takes off like a rocket... The strange thing, is that it behaves the same way when i drive with the v-boost open. (I pulled the plug out when turning the ignition on). I'm starting to think it must be something else...? Have also measured the coils and they're giving around 13.4V.

I'm out of ideas... :ummm:

 

[The Beekeeper]

Have you tried a fresh set of plugs?...........Simple things first..........Tom.

 

[Norway Max]

Hi all,

Yes, brand new plugs are in... Did a third cleaning now, and it's much better. Strange thing is that the sputtering cylinder is now good, but the one in front of it has started to act up. Looks like i've managed to move the problem forward... :clapping:I'm leaving for work now for 5 weeks anyway, so i'm leaving it like this for now... Good thing is that it must be a carburetor problem, and not something more serious. Maybe a a/f adjustment is needed...

 

[jfeagins]

Perhaps one or more carbs starving for fuel - UNTIL - Vboost opens, allowing fuel mix to be pulled from another carb? Vent tubes unrestricted on all four carbs?

 

[one2dmax]

Are you running an airbox (and faux tank cover)? Possibly CDI issue (if you have those other parts in place).

Sean

 

[TurcoLoco]

How clean/fresh is the fuel? Perhaps a 1/3-1/2 can Seafoam wouldn't hurt?
I'd definitely check the a/f adjustment but also perhaps the float levels are off, at least on that problematic carb?
It sounded like it is running either too rich or too lean on that carb.

 

[Norway Max]

Yes "jfeagins" feels like it's starving for fuel, i will have a closer look when i'm back home from work.

one2dmax: The bike is completely original, so i have an airbox and faux cover. But i'm not sure what you mean by CDI...?

TurcoLoco: I don't think we have something called seafoam here in norway, maybe something similar, but don't really know what it is...? Sorry... :confused2:

Anyway, i'll do some more research in 5 weeks. Thank you all for your help. I really appreciate it.

 

[Norway Max]

Hello Guys!

Came back from work two weeks ago, and started to faultfind my carb probs again. I took off the air-filter and was standing there looking down the intakes. I saw something was wrong, but couldn't put my finger on it. But then.... i saw the problem... :eusa_dance:
The needle seat on the carb having problems, had loosened and slid about 2mm into the intake... :bang head:

I took off the carbs, managed to take the one carb out and get into the float chamber. The screw holding the needle seat was loose of course, so tightening it pulled the seat back in place again. Mounted everything back together, synced the carbs again, and VOIL?!! Runs perfect! :biglaugh:

I'm complete again...

Thank you guys for all your help, and have a trouble-free season.

Norway Max