Member Contributer Skids Posted March 6 Author Member Contributer Share Posted March 6 Thanks guys, will take an in-depth look at this soon. Quote Link to comment Share on other sites More sharing options...
vfrgiving Posted March 6 Share Posted March 6 FYI, the physical copy of the service manual I have says DO NOT mess with the lock nut. MOTWYW 1 1 Quote Link to comment Share on other sites More sharing options...
Member Contributer bmart Posted March 7 Member Contributer Share Posted March 7 I have this strong desire to mess with the lock nut. Is this a don't cross the streams kind of thing? 🙂 Quote Link to comment Share on other sites More sharing options...
Member Contributer Terry Posted March 7 Member Contributer Share Posted March 7 There's a balance involved between the starter valves, the idle stop screw and the wax unit nut. If you mess with one, you may mess up the other inadvertantly. Another member unwisely messed with the "unadjustable" starter valve screw (#4?) when synching the throttle bodies and closed those down more than they should be (but they were all nicely in balance 🙂). That resulted in the idle stop screw having to be wound in in much more than usual to get the warm idle correct to hold the starter valves open enough. And that resulted in the starter valve opening mechanism being held unnaturally open when the engine was cold to the point where the wax unit wasn't adding any cold opening to the SVs at all. Which means the cold start idle speed was unpleasantly low. If you can verify that the wax unit is changing it's length as the coolant temperature is changing but just not by enough to lift the SVs open when cold, then I would have a crack at changing the unadjustable nut, but at the very least mark the "factory" position before you start so if/when it all goes tits-up, you can return to the original setting. 3 Quote Link to comment Share on other sites More sharing options...
Member Contributer raYzerman Posted March 7 Member Contributer Share Posted March 7 IF one messed with starter valve #1, one has changed the reference.... best not mess with that. Idle speed can be adjusted normally, provided the wax unit isn't affecting it. I wouldn't hesitate to move the lock nut if I had to. You should be able to tweak the high idle with it, meaning, no affect on regular idle speed, yet getting a good high idle for warmup. However, I'd take the earlier advice to ensure everything is not corroded and free to work properly. Quote Link to comment Share on other sites More sharing options...
Member Contributer Skids Posted March 7 Author Member Contributer Share Posted March 7 I haven't messed with anything yet, certainly not #1 or any other SV, which is why I'm suspecting the wax unit as the bike was fine last year. There not a spot of corrosion on her either so I'm struggling to see how any of the SV or wax unit could have corrosion. Quote Link to comment Share on other sites More sharing options...
Member Contributer Presson Posted March 7 Member Contributer Share Posted March 7 Galvanic corrosion between the brass part and the steel actuator arm. If possible examine operation of the wax unit actuator arm by sight. When the engine is warm and the idle has risen, can you move the SV actuator arm using a screwdriver or pliers to apply pressure to overcome any corrosion induced 'sticktion'? If the wax unit has failed there should surely be some evidence of leakage via one of the o rings...? The rationale in the manual for not touching the wax unit locknut is to avoid fiddling with a number of settings and upsetting the relationship Terry describes above. If you only touch one setting you should be able to get back to where you are now Quote Link to comment Share on other sites More sharing options...
Member Contributer Presson Posted March 7 Member Contributer Share Posted March 7 Look at the photos you posted on Tuesday. Evidence of corrosion between the brass part and the steel actuator that might cause sticking Quote Link to comment Share on other sites More sharing options...
Member Contributer Presson Posted March 7 Member Contributer Share Posted March 7 Or is that calcified deposits from washing with hard water? Perhaps that could cause sticktion Quote Link to comment Share on other sites More sharing options...
vfrfuzzywuzzy Posted March 20 Share Posted March 20 I had a similar experience after using Risolone coolant flush. After bringing temp up to about 160 degrees,idle went and stayed around 2500 to 3000 RPM. Repeating shutdown and restart again and again,I immediately let cool a bit and drained/flushed entire system and restarted with plain water. I did this 3 times before normal RPM operation returned with clean anti freeze. The wax unit must be very sensitive I concluded especially after reading this post. Scared the living crap out of me. This may not pertain exactly to this post,but has some similarities. 1 1 Quote Link to comment Share on other sites More sharing options...
Member Contributer Skids Posted March 20 Author Member Contributer Share Posted March 20 Thanks fuzzy. Thing is the bike ran fine last summer, albeit only a couple of hundred miles, after I changed the coolant.🤔 Quote Link to comment Share on other sites More sharing options...
Member Contributer Skids Posted March 31 Author Member Contributer Share Posted March 31 On 2/3/2024 at 2:15 PM, Presson said: I confess I've no actual experience of the wax unit, but could a stuck wax unit piston cause the problem you describe by keeping the SVs wide open? From reading around it sounds as though the wax units normally last over 100k miles. Well, I think the prize goes to Presson. I removed the airbox and was looking to take the wax unit apart but then thought I'd just give it a proper warm through first whilst the tank was raised and with much of the gubbins out of the way so I could watch it and it looked like the piston/rod was sticking so I sprayed it with WD40, moved it around by hand a little then tried again and it idles fine when warm. I have yet to take her out on the road to try her out but that will have to wait. Balanced SVs whilst I was there too. Can folk confirm this is the correct way now we all realised we were doing it wrong for 20-odd years? So thanks Presson, much obliged! 2 Quote Link to comment Share on other sites More sharing options...
Member Contributer Presson Posted March 31 Member Contributer Share Posted March 31 A lucky guess on my part; KISS! Glad you got it fixed. Quote Link to comment Share on other sites More sharing options...
Member Contributer Bren Posted April 1 Member Contributer Share Posted April 1 19 hours ago, Skids said: Balanced SVs whilst I was there too. Can folk confirm this is the correct way now we all realised we were doing it wrong for 20-odd years? That's how I've always interpreted the manual description and set mine. More vacuum (= a minus in the settings relative to no. 1 the base setting) raises the Mercury in the tube. Hoping I understood it correctly too! 1 Quote Link to comment Share on other sites More sharing options...
Member Contributer Bren Posted April 1 Member Contributer Share Posted April 1 Difficult to get 100% right due to the fluttering even with the dampeners adjusted. Quote Link to comment Share on other sites More sharing options...
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