Hello,

I removed the throttle body+air plenum ensemble on my K100 for cleaning and inspection. The intake manifolds, I have kept bolted to the crankcase, as they appear in good condition.

Are there tips for re-seating the throttle bodies into the intake manifolds? I can align them and apply pressure onto the air plenum box to force them down but they won't go in far.

The plenum chamber is a RRPITA to get back on. My method is to

- use silicon grease around the inlets
- position the plenum chamber over the TBs
- push it down as far as it will go and sit it as level as possible
- using a hefty 10mm blade screwdriver (or similar) between the frame and the plenum chamber, lever the plenum chamber down hard
- protect the frame with a piece of cloth if wanted.
- rear first, followed by the front


I find they go on with a nice noisy pop! if done this way and it leaves you in no doubt that they are sitting fully on the TBs.

Hi, I've moved your post from Technical Repair & Troubleshooting to Technical Repair & Troubleshooting - Engine & Transmission because it's specific to your question. You chose the generic header which doesn't help much later on if someone's researching.

Try using the Forum's Search Bar. I typed in "refitting airbox" and some direct answers popped up with what you're asking. See what others before you have experienced. 

In my experience it requires patience, the right angle, and some form of lubricant. I start with a beer for me, then move on to silicone or soap for the airbox to TBs.

"Refitting Airbox"

Thank you both

Is petroleum jelly a bad idea for lubricant? Or dawn dish soap?
I have silicon lubricant (not grease) but it's quite thin and doesn't help much.

I provided you with a link - in blue - in my previous post. Press on that and it'll take you to one that's pretty clear. I dunno about Petroleum Jelly but I've used a healthy blast of silicone spray to ease in refitting them. Dai's particular technique works.

I see, in the link RT recommends a little bit of Vaseline, which is what I meant by petroleum jelly. Thank you.

Not sure if this is causing you issues but I temporarily zip-tie the wiring above out of the way to add clearance.