what did you wrench on today??

[dgates1]

I sometimes feel I do more harm than good when syncing. It's so difficult getting access and tightening without throwing them off. Both bikes idle fantastic and my old Motion Pro mercury set shows them looking pretty even. It could be better and more proper per spec, but I don't think I am skilled enough.

I did end up changing out my Carb Sync Screws for hex-head cap screws with a washer and spring on them. Found the M5x0.5 pitch screws on eBay from China (search for "M5 fine thread"). Had ordered 20mm length and they were too long and interfered with the choke rail. The 16mm length ones I ordered next were just right. Also ordered 7mm OD x 5mm ID x 15mm Long SS springs. These were good on the 20mm screw but too long for the 16m screw. Ended up cutting them to about 10-11mm length and installed with a SS M5 washer at the top of the screw.





I had done a vacuum sync right before this with the 11" long "special tool" that is suppose to work and it was difficult to get them balanced really good. Used a micrometer to crudely "measure" where the throttle valves were. I installed the new screws/springs and tried to match with the carbs still on the bike. It started but was not very happy... might be better to pull the carbs and do a bench sync.

After they were installed and I did the sync again, it was really easy to dial them in to be just about perfect with a 4mm ball end bit on a 6" bit holder. Yes.. I know everything is really dirty right now (she just woke up from an 8 year nap) and I did replace my O-rings in the boots.

Time will tell if they hold their position.

[oldGSfan]

I did end up changing out my Carb Sync Screws for hex-head cap screws with a washer and spring on them. Found the M5x0.5 pitch screws on eBay from China (search for "M5 fine thread"). Had ordered 20mm length and they were too long and interfered with the choke rail. The 16mm length ones I ordered next were just right. Also ordered 7mm OD x 5mm ID x 15mm Long SS springs. These were good on the 20mm screw but too long for the 16m screw. Ended up cutting them to about 10-11mm length and installed with a SS M5 washer at the top of the screw.

I had done a vacuum sync right before this with the 11" long "special tool" that is suppose to work and it was difficult to get them balanced really good. Used a micrometer to crudely "measure" where the throttle valves were. I installed the new screws/springs and tried to match with the carbs still on the bike. It started but was not very happy... might be better to pull the carbs and do a bench sync.

After they were installed and I did the sync again, it was really easy to dial them in to be just about perfect with a 4mm ball end bit on a 6" bit holder. Yes.. I know everything is really dirty right now (she just woke up from an 8 year nap) and I did replace my O-rings in the boots.

Time will tell if they hold their position.

Oh that's a clever idea. I should try that. I was tuning my son's friend's DR-Z400 carb the other day and the idle mixture screw (fuel adjustment type) is impossible to get to, it's under the carb and very little clearance. What a bugger! They sell extended screws with a knurled knob (eek!) and I recommended he get one, because I simply couldn't adjust it. I had put it to a setting that I read was about right, 3 turns - it was out 5 - and the bike runs good. But I like to fine tune if possible.

That got me thinking 'why do they do that?' and all I can figure is that the carb maker and the bike maker aren't on the same page, they aren't designed specifically for the bike. Old boxer BMWs are so simple to adjust, and overall I remember never having an issue swinging a wrench on them. None of that 1/8 turn, flip the wrench, another 1/8. They seemed to be built to work on. Unlike the modern ones. This pic is funny, must be a joke. Right?

[Baatfam]

This pic is funny, must be a joke. Right?

Maybe not. This is my K1100RS getting a spline lube....

BMW Spline Lube 20 by R John Thieda, on Flickr

[alke46]

Ridiculous.......fine German engineering eh?

[johnod]

Maybe not. This is my K1100RS getting a spline lube....

BMW Spline Lube 20 by R John Thieda, on Flickr

Well that looks like fun.
Had a K1200RS, great bike, but too complex to enjoy working on imo.