MOTOBRICK.COM
TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: carlhook on August 21, 2018, 03:30:52 PM
-
I'm having a mystery issue with k75.
Had a blown fuel pump, replaced the whole kit, all the lines, everything except the injectors and fuel pressure regulator.
Cleaned the injectors via compressed air and petrol (there was rubber type of slushy in the fuel rail) They seem to spray ok, spark plugs are all showing the same, so injectors might be bad, but equally bad then :D So not like one cylinder works and others don't.
replaced the spark plugs, air filter, maf seems to work ok aswell.
Power wise the bike pulls strong, the TPS has been set correct, same issue with it unplugged aswell.
Fuel pressure is held at steady 36-38psi.
Fan kicks on so the temp sensor works.
I have not taken all the throotle bodies apart, but whilst spraying the whole engine with brake cleaner it did not react, so it should not be it then?
Pretty much whilst driving the bike has 1 second delay and then it pulls strong.
What am I missing?
<iframe width="560" height="315" src="https://www.youtube.com/embed/9EUpUEltitg" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>
-
https://www.youtube.com/watch?v=9EUpUEltitg
-
plugs
-
I have not checked the valve clearance (they sound loose to me, not tight)
And have not touched the MAF regulation.
The throotle bodies have been synced up nicely.
-
hesitation for a half second or so is normal, especially when you whack open the throttle like that. Mine has done it since day one. Stalling out is not, as at the end our the vid, but try less aggressive throttle. That's the nature of the beast.
-
hesitation for a half second or so is normal, especially when you whack open the throttle like that. Mine has done it since day one. Stalling out is not, as at the end our the vid, but try less aggressive throttle. That's the nature of the beast.
I will try to make another video, as this does not show it fully, it totally stalls out and even pings when warmed up and giving it throttle.
Poor throotle response is ok with me, but not 1 second lag and misfire/bog.
-
greetings..
4 pin... trust me on this... sounds whack... cause it is whack... trust me on this...
j o
-
greetings..
4 pin... trust me on this... sounds whack... cause it is whack... trust me on this...
j o
The 4 pin to the gas tank? it had a sketchy connection but I fixed it
-
Better video
https://www.youtube.com/watch?v=CKsaOR0sjR0&feature=youtu.be
-
Throttle response is normal, they all do it because of the lag from the MAF flapper signal to the Jetronic. The Motronic desn't have the lag because the throttle position is used to dose the fuel.
-
Throttle response is normal, they all do it because of the lag from the MAF flapper signal to the Jetronic. The Motronic desn't have the lag because the throttle position is used to dose the fuel.
So the MAF flapper could be bad? as it bogs and dies also in the video, and lags way more than normal.
-
. . . spark plugs are all showing the same, . . .
I have not taken all the throotle bodies apart, but whilst spraying the whole engine with brake cleaner it did not react, so it should not be it then? . . .
I have not checked the valve clearance (they sound loose to me, not tight)
Are you asserting here that you can distinguish the sounds made by each of the six valves in the engine? That's what I call intimacy. :clap:
Spraying the whole engine with brake cleaner to check for intake leaks isn't the way to go, especially if the brake cleaner is the non-inflammable type. Carefully directing a spray around each manifold with carb cleaner or propane works better. Is the z-tube running from the air box to the crankcase in good condition?
The middle plug's electrode in your photo doesn't look like the others to me.
Checking valve clearances is a nothing-burger of a task. It's appropriate to do it before the synch. Don't get involved with an MAF that you have already asserted was ok until you've checked your clearances then reset your idle.