Good day, gentlemen!
I have a potentially big problem with my throttle body. While cleaning it, I removed the molybdenum coatings and I really want to fix this issue and not discard the throttle body as a whole. I have purchased some molybdenum disulfide, only to find that it has to be dilluted with another unknown compound to be able to use it.
I found a video on YT with someone sealing a carburettor butterfly valve with some compound he says it's really hard to find, called DHE213...google search shows no relevant infos.
Can someone enlighten me and others who made this mistake?
Thanks in advance!
Zoltan
Why bother ? The coating it jjst to stop corrosion. Degrease & paint with alloy etch primer & a top coat.
2 hours ago, Mohawk
Why bother ? The coating it jjst to stop corrosion. Degrease & paint with alloy etch primer & a top coat.
No Sir. The coating is there to seal the butterflies when closed. If the coating is damaged or removed greater bypass air increases idle speed which the starter valves can't properly compensate for. End result is high uncontrollable idle speed.
The one person I've heard that experienced this had to replace the whole throttle body if I remember correctly!
Makes you wonder if there might be some specialist engineering business out there that could professionally repair or replace the Molybdenum Coating??
Mr Google found me a Patent application for a novel form of application equipment for the moly coating, but had the following words:
"Over time, during use of the fuel system, a carbon-based sludge seal will form between the plate member and the wall member to close the annular gap. This seal will be formed by the fuel system component byproducts.
If this seal is allowed to form during the use of the fuel system, the amount of air introduced, and thus, the operating conditions of the fuel system, will have varied overtime. Accordingly, it is desirable, and has been industry practice, to form a seal in the throttle body assembly to cover the annular gap during production of the throttle body assemblies to provide a throttle body assembly which can have continuous and stable use.
Typical sealant compositions comprise a Molybdenum disulfide/MEK solution, such as Molydag® from Acheson, which is further diluted with an additional 10-20 weight percent of MEK."
I thought he said he lost the coating from an avid bath some such so no loss of material. Over bored throttle bodies work just fine in bare alloy & as the VFR does not rely on the throttle plate for idle speed control due to the starter valves (that is what leads to the snatch off idle) either way I don't believe that coating is required. Alternately buy a second hand set of TB's they are cheap enough.