2000 st1100 knocking noise and oil coming out of one carb

Hey guys,

I'm new to honda V4 world (been everything but that for past 15 years) anyways I got a st1100 with 6k miles yes believe it or not that is the actually millage anyways bike runs kind of rough it quiet when under load but once you roll the throttle back it makes noise almost like valves were suuupppperrrrrrrrrr lose or timing was off ( i checked the timing and everything seems to line up properly) I checked the plugs 3 r dry one is wet I think that would be cylinder that somehow pisses oil into the carb maybe (with would maybe explain engine bogging at 4-5k rpm)? Anyways any help would appreciated if someone is local in Bay Area CA then maybe we could meet up and somebody could take a look at it.

Thanx guys

is the bad plug from the rear right cylinder? If so, it may have gotten fouled by a failing vacuum fuel shutoff valve. If that's the case, its an easy fix.

dwalby said:

is the bad plug from the rear right cylinder? If so, it may have gotten fouled by a failing vacuum fuel shutoff valve. If that's the case, its an easy fix.

Click to expand...

Right front

Not sure I understand how oil from the engine gets into the carburetor???

As for the noise, there have been a few reports of the timing gear pulley bearing in the head going bad. When that happens the seal goes with it.


Sent from my iPhone using Tapatalk

Check the oil level, if it is over half in the sight glass it could cause noise and oil into the air cleaner and carbs.

Slydynbye said:

Check the oil level, if it is over half in the sight glass it could cause noise and oil into the air cleaner and carbs.

Click to expand...

I will check that tomorrow hopefully that is the problem
Thank you

Be sure to check the oil sight glass with the bike on the center stand.A

Also if that bike sat for a while you might have to go through the carb bowls - make sure needles are clean and fuel needle valves are not stuck.

Thanx guys I will check all this stuff later tonight also I ordered owners manual should be here by the weekend

polishadam82 said:

Thanx guys I will check all this stuff later tonight also I ordered owners manual should be here by the weekend

Click to expand...

I hope you ordered the Service Manual, as the owner's manual won't be of any help.

A little oil mist in the airbox is normal, there is a crankcase vent pipe that connects to the underside of the airbox on the right side; lots of oil there is not normal and may be a sign that the engine is over-full of oil.

My ST11 had a bad misfire from 4K upwards that turned out to be due to weak voltage reaching the ECU, in turn due to some corrosion around pins in the red connector that feeds power to/from the right bar switches. I also found a weak connection in one spark plug lead to the coil. With new plugs (cheap insurance) my problems disappeared. There are a number of such connectors right in front of the airbox, behind the steering head.

I wonder if your engine noise might actually be a rusted baffle in the exhaust?

yes that's what I mean Clayton service manual

alright so I did drain some oil like you guys suggested and it helped it runs better there is still some oil mist coming from the engine crankcase tho but it does run way better only thing now is that weird knocking noise I checked timing and everything lined up so any other ideas?

polishadam82 said:

alright so I did drain some oil like you guys suggested and it helped it runs better there is still some oil mist coming from the engine crankcase tho but it does run way better only thing now is that weird knocking noise I checked timing and everything lined up so any other ideas?

Click to expand...

Well, hopefully to keep the 'fix' simple, change ALL four plugs for new ones. Also, to keep it simple again.....if idle is under 11-1200rpm when totally warmed up from riding, that knock will exist at idle. Also will exist if carbs haven't had idle mixtures re-set and THEN a carb - sync done. Ooopps....forgot...oil level NEEDS to be just below the full mark, checked when cold, after sitting preferably overnite on centerstand).

Brant said:

Well, hopefully to keep the 'fix' simple, change ALL four plugs for new ones. Also, to keep it simple again.....if idle is under 11-1200rpm when totally warmed up from riding, that knock will exist at idle. Also will exist if carbs haven't had idle mixtures re-set and THEN a carb - sync done. Ooopps....forgot...oil level NEEDS to be just below the full mark, checked when cold, after sitting preferably overnite on centerstand).

Click to expand...

Sounds good Brant I will order some new plugs tonight

Wanna bet new spark plugs won't make a difference ??

Jim Van said:

Wanna bet new spark plugs won't make a difference ??

Click to expand...

he did say earlier that he had one fouled plug, so either cleaning it up or replacing it would make sense. If the knock goes away with the new plug, that's good info. But then he will need to determine why the plug fouled in the first place.

Jim Van said:

Wanna bet new spark plugs won't make a difference ??

Click to expand...

No bet Jim, but new plugs prior to bike possibly needing a carb sync IS all good

Carbs that are out of synch, improper idle mixture settings as well as having a bad plug or weak spark on one cylinder can cause a knocking sound particularly at idle on the St1100's.

Also the exhaust header heat shields can make quite a racket when rolling off the throttle as a harmonic can develop and cause the shield to resonate at different rpm's and loads. Sometimes the screws are loose or the shields are cracked around the screw holes. I have also seen the header nuts become loose where the header fits up into the cylinder heads. With such a low mile bike I think that taking a look at these points may lead you to the problem.

Dan

thanx guys new plugs should be here Wed I will keep you guys posted on progress thanx again this is great group of people here