Can't sync the carbs...

[Zenuwlijer]

A/F screws

As said, I went for a long ride yesterday.

A/F settings: 2 3/4 on all carbs.

I noticed very quickly that the bike was running hotter than it did before. Rode it all the same, because I had to and the oil temperature* didn't ever exceed 120 degrees Celsius. For about 80% of the time it ran in the 103-110 range.

*(Oil temperature sensor attached to oil gallery plug and inspected sensor and gauge with boiling water test.)

When I was back at home, I parked the bike and let it cool down overnight.

As a coolant system flush is due, this could be problem. It seems to me the "overheating" wouldn't occur from one day to another, so I will inspect the sparkplugs as I intended to do anyway.

Time to pull the spark plugs:












Found the problem. It's running lean. How is this possible with my current A/F settings? If any, it should be running rich...

 

[Parminio]

That actually doesn't look bad at all to me. Looks like it ran hot. Typically if you're running very lean you'll get that white residue on the sides of the core electrode. I don't see that at all. They look brand new.

 

[Zenuwlijer]

They look brand new.

They are. I only put 50 km on them before I started the whole endeavour with the synchronization of the carbs. Yesterday I put another 400 km on them.

 

[Zenuwlijer]

I'll proceed with the cooling system flush first. I didn't do that the last time when I renewed the coolant. Don't know if it's ever done by the previous owner.

 

[Parminio]

I'll proceed with the cooling system flush first. I didn't do that the last time when I renewed the coolant. Don't know if it's ever done by the previous owner.

Just make sure to follow the proper procedure. People that have not have wound up with air in the system that makes their bikes overheat.

 

[Zenuwlijer]

Thanks for the tip. Should be ok.

I'm the kind of guy that actually uses the Haynes manual or (veryfied) walkthrough procedures from forum members.

 

[patate657]

Just make sure to follow the proper procedure. People that have not have wound up with air in the system that makes their bikes overheat.

What is that procedure, please? On a car I'd crack open a heater line and it'd let out air. On my my bike I wasn't sure.

 

[Fire-medic]

What is that procedure, please? On a car I'd crack open a heater line and it'd let out air. On my my bike I wasn't sure.

The process for the cooling system black valve at the front of the engine is in the shop manual.

VMX12- Service-Manual.pdf (vmoa.net)

 

[Zenuwlijer]

 

[Zenuwlijer]

Expensive little buggers.. Together with the demi water, the flushing agent and the coolant.. I'm at 85 dollars.

 

[Parminio]

Take that chrome grill off your radiator and your temperature will drop 20 degrees.

 

[Zenuwlijer]

Take that chrome grill off your radiator and your temperature will drop 20 degrees.

The airflow would be better indeed.

 

[Zenuwlijer]

Overheating solved by using normal (specified) sparkplug gap.

 

[Fire-medic]

Hey, whatever works. I believe in most cases, 'factory knows-best.'

 

[sdt354]

I can't see how plug gap would? A flushing with an air purge more likely.

 

[Zenuwlijer]

I can't see how plug gap would? A flushing with an air purge more likely.

You tell me...

On the other hand I can only state the facts as I've observed them.

I did not change anything on the A/F side when I narrowed the gap and it started heating up. Didn't change anything either when I put the "factory spec" plugs in.

Overheating disappeared though..

Then again... Y'all could tell me anything and I'd believe it because of my total lack of knowledge.

As a noob, I'm just trying to make sense of it all.

 

[Fire-medic]

(17) New Vmax Owner FAQs....new members please read! | Yamaha Star V-Max VMAX Motorcycle Discussion Forum (vmaxforum.net)

Your weekend reading assignment.

 

[DreamV4]

The front sync screw on the right hand side (#4) syncs #3 & #4 to the left side carbs.

sync procedure:
-2 is the master carb, everything is sync'd to it
-sync 1 to 2 using the sync screw on 1
-sync 3 to 4 using the sync screw on 3
-sync 3-4 to 1-2 using the sync screw on 4

Based on dannmax post, you need to use only 2 gauges. If you use 4 of them, it means you didn't read manual synch procedure.
I made synch tool with $3 materials, it only has 1 gauge and works perfectly. At least 10 bikes synchronized.

 

[Screwloose]

Your weekend reading assignment.

Is there an exam next week?

 

[Fire-medic]

Is there an exam next week?

Proctologically-speaking, no.

Personal edification will suffice.