Re-cleaning the carbs...remove o-rings? Best carb sync gauge?

[giganticflying]

Hey everyone,

So I had a decent go with my bike after I tore apart the carbs, dipped, cleaned and replaced the o-rings, bench synced, changed oil/gear oil, resealed airbox, and got new points. The bike started up and ran for a bit (a little puttery on the acceleration), but now it hardly idles without choke. I also noticed that cylinders #3 and #4 take a lot longer to warm up, but many signs point to them working (spark plugs, heat from exhaust after riding), just not so much in idle.

I'm assuming there is still somethings I missed with the carb. I didn't check float height and I didn't do an actually carb sync with a gauge. I also didn't check the valve clearance, so I'm taking it back apart to do it all over again, thoroughly this time. .


Question: Since I have brand new o-rings on the carb parts, should I take them off before I clean them? I'm only going to dip the carb bodies but I want to spray the small parts just in case there is some crap in a some small hole or crevice that may be messing with the bike. Also, what carb sync gauges should I get on a budget? I've see the Morgan Carbtune mentioned a lot on here...any cheaper options?

I'm also going to replace the petcock (oil smells a little like gas, that'll be a whole different thread I'm sure), and check the valve clearance.

As always, thanks for your help!

 

[giganticflying]

Some other things to note about my running issues:

The boots still seem rubbery so I didn't replace them. I did replace the o-rings for the boots on the engine side.

I did replace the gaskets and screws on the carbs.

I have a new head gasket for the engine. There seems to be a very slow oil leak at the top left from around that half moon thing. Does anyone know where to get those?

I am getting spark on all 4 wires/plugs but I didn't check the sync since I haven't done anything to mess with the timing.

Any tips appreciated.

 

[Guest]

Sounds like you still have some issues with the carbs on the idle/slow speed circuit. And yeah pull ALL the orings out before dipping them. There is a VM carb rebuild tutorial on BikeCliff's website http://members.dslextreme.com/users/bikecliff/

 

[giganticflying]

Awesome. Thanks for the advice.

Just to add to the picture, that is the carb rebuild guide I followed the first time around, I just skipped the part on syncing with a carb gauge since I'm naive and didn't have one.

 

[eil]

All of the things you said you skipped can cause issues with running at idle.

I would do the valve clearance first. New valve cover gasket from Z1 or an OEM vendor. Then do the carbs. You can clean them again if you're not sure you did a good job the first time. If you followed the instructions in the tutorials you shouldn't have to do them again. Though it certainly won't hurt. Yes, set the fuel height. Yes, remove the o-rings before letting carb cleaner anywhere near them.

Vacuum sync is highly recommended and often solves idling issues. The Morgan Carbtune is recommended because it's best in its class and if you plan to keep owning motorcycles going forward, you'll certainly use it again.

 

[2BRacing]

Some other things to note about my running issues:

I am getting spark on all 4 wires/plugs but I didn't check the sync since I haven't done anything to mess with the timing.

Any tips appreciated.

These two things, synch and timing, are completely unrelated. Synching the carbs with the proper gauge on a warmed-up engine will ensure that all 4 carbs work perfectly together, BUT this should only be done AFTER you have adjusted all the valve clearances.

Incorrect timing (as in ignition timing) means that the spark occurs at the wrong time in relation to Top Dead Centre (TDC) of the crankshaft, corrected by adjusting the plate inside the round ignition cover on the right hand side. Incorrect valve timing means the relationship between crankshaft and camshafts, linked together via the cam chain, is not correct and is corrected by ensuring the marks and arrows on the cams line up correctly and have the correct number of cam chain links between the relevant arrows.

 

[giganticflying]

Sorry, a little misworded. I didn't check the timing on the points because I didn't mess with anything that had to do with timing or the crankshaft. The spark/timing on the points appear to be correct, and I read in a couple of places that if the crankcase hasn't been dissembled then its probably fine to just replace the points/condensers and set the gap without checking the timing.

 

[Big T]

Sorry, a little misworded. I didn't check the timing on the points because I didn't mess with anything that had to do with timing or the crankshaft. The spark/timing on the points appear to be correct, and I read in a couple of places that if the crankcase hasn't been dissembled then its probably fine to just replace the points/condensers and set the gap without checking the timing.

No, and no again

Always verify your timing with a strobe

Order a valve cover gasket and half moons - I use Beaverton MC, as I only live a mile away, and it's not worth waiting for the online vendor to ship parts to you and then have to pay shipping.

You wait twice as long and save 1.75

You'll need a shim tool and the right feeler gauge to check the valves. Get a spread sheet from Steve while you're waiting.

Go back and read the Top 10 Newbie mistakes and see where you stand. Your shortcuts are becoming longcuts