EFI Throttle Body Advise Needed

[tatt22er]

A couple of weeks ago coming home from a local watering hole for the first time ever the Dog kind of hiccuped, which it has never done since I've owned it, especially since I have the EFI. After it warmed up it wouldn't do it again and would run fine, the next time I rode it, same thing happened but it seemed to happen only when I would get on the throttle, I'm thinking it has to be spark or the fuel. I checked the plugs, they looked good but I replaced them anyway, rode it again, same thing, same symptoms, so I got on BDB and started to do some research and read someone who was having similar problems with a carb mentioned maybe there was a air leak in the intake manifold, I thought maybe that could be the problem. So today I took the the air filter cover off to check the backplate so see if anything might have vibrateed loose, as I checked the backplate screws to make sure they were all tight I noticed that the top screw was very loose and tried to tighten it, it would not tighten, I thought this can't be good, so I removed the backplate to find that where the screw threads into the throttle body had broken. Here is the photo. Is there anyway to repair this or am I just screwed and going to have to buy another one, if having to buy another one should I replace all the sensors or is there an upgraded unit to replace this one. Any thoughts would be greatly appreicated.

 

[RCAdd1ct]

Not good, but not where you would cause a leak that could cause your issue.


Where the normal issue is where the manifold connects to the heads. Now if that being loose has messed up the seals at the head it might be the cause.

A good welder might be able to fix that, but more than likely you are looking at a new tb.

 

[chacha]

Pull it off the bike and check with a local machine shop--they may be able to fix you up. If not, the part comes "naked" so you'll have to pull the sensors and fit them on the new one -- not hard.

 

[RCAdd1ct]

you might be able to red loctite a stud on the top hole.....but then you would have to space out the nut inside the air cleaner.

If you do this make sure you drill the end of the stud for safely wire to make sure it does not come loose and make it into the engine.

In fact you might be able to pin the stud in the TB and secure it there, too.

 

[Hillsidecycle.com]

Looks like that mounting hole, needs to be welded, machined, and drilled/tapped to repair correctly.
Scott

 

[tatt22er]

Thank you all for the input, most likely buy a replacement and change over the sensors and check the intake manifold for any possible leaks. Curious, read on here that there is a way to change to a wide band injectors or is that got something to do with the map readings in the ECU, things needed to properly do performance upgrades.

 

[08mastiff]

I have the same problem on mine also. Not that it's problem but you just can't get on it for a couple of miles when it starts from cold. It feels like it has a missfire. Just let it warm up good and be easy in the beginning.

 

[erldawg]

I have the same problem on mine also. Not that it's problem but you just can't get on it for a couple of miles when it starts from cold. It feels like it has a missfire. Just let it warm up good and be easy in the beginning.

Ditto...Mine did it with the original ECU and the new unlocked one. I'm wondering if it may be a tad lean on cool starts. It usually clears in a couple of blocks after it warms up. Not good to throttle to hard when it's cold anyway.

 

[RCAdd1ct]

Wide and O2 sensors.

Injectors are measured by flow rate.

 

[erldawg]

Thank you all for the input, most likely buy a replacement and change over the sensors and check the intake manifold for any possible leaks. Curious, read on here that there is a way to change to a wide band injectors or is that got something to do with the map readings in the ECU, things needed to properly do performance upgrades.

You would have to change the ECU if you wanted to go with wide band o2 sensors.
I recently made an adjustment to the ECU in the "Accel" feature in the Pro II software. It changes the sensitivity to throttle openings and adds a burst of fuel upon acceleration. This seems to have eliminated the hesitation / misfire when the engine is not fully warmed up. I've only taken one ride since the change so time will tell. Please note I changed my ECU to an unlocked version of the S&S if you have the stock S&S ECU it cannot be changed.

 

[RCAdd1ct]

And from what I am told the S&S ECU locked or unlocked will only accept Narrow band O2 sensors.

You would need to swap to like a thundermax to use the wideband sensors.

Not sure how difficult the total ECU swap...wiring and all would be.

 

[Nomad2day]

And from what I am told the S&S ECU locked or unlocked will only accept Narrow band O2 sensors.

You would need to swap to like a thundermax to use the wideband sensors.

Not sure how difficult the total ECU swap...wiring and all would be.

I run a Thundermax wide band with auto tune in my 07 Bulldog....
Had it in for a few years... No issues at all..
Neil