Starter valve sync

[jstehman]

 

Today I dove into the starter valves.

 

Took off the airbox cover and removed the filter.

 

Disconnected 2 electrical connectors I am guessing the IAT white connector cone shaped (comes through the housing tray), and the grey connector at the back of the lower airbox tray.

 

I did not block off the pair valve hoses but did disconnect them from the tray.

 

I fished out the 4 throttle body vacuum line manifold and connected my Carbtune. Started the engine.

 

Idle sat around 1200 rpm. FI light on assuming because connectors disconnected.

 

Cylinder 1 was pretty far out so I adjusted that to match #4.

 

2 and 3 were real close, so I adjusted those to 4 and examined the tools reading. All 4 dead straight across the board. Shut the engine off. Reconnected vac lines and electrical connectors. Reinstalled velocity stacks.

 

** My stacks were short in front and tall in rear. Pretty sure no one has been in there since the factory. **

 

Buttoned up the air cleaner housing, reconnected the flapper line, closed the tank and fired up the engine. Idle at 850rpm

 

Adjusted idle with screw under fairing to 1200rpm.

 

Checked throttle response:

Can hold steady throttle up to 3000rpm without surging. Drop to idle and raise to 3000 slowly.. no surge to 3500-4000. Steady rpm!

 

Went for a road test. Had to re-acquaint ourselves with the bike.. she was a little different without the surging. Second gear in the neighborhood was much more delightful without the bucking bronco snatchy jerkiness before.

 

She feels a bit peppier too. Exhaust note sounds different.. more pronounced I guess is the word.

 

Can someone double check my work and see if I did something incorrectly?

 

 

 

Sent from my SM-N950U using Tapatalk

 

 

[Grum]

Great job. Sounds like you've done a good set up per 6gen. The two sensors you unplug are the IAT the white cone shaped thing you mentioned and the MAP sensor. And yes it's normal during the process for the ECM to flag up a fault code for these devices.

 

Your intake funnels have definetly been previously tampered with... At the front two cylinders 2 and 4 you should have a Short (left) and a Long (right). The rear two cylinders 1 and 3 you should have a Long (left) and a Short (right).

 

Cheers.

[jstehman]

So bizarre about the intake funnels!

 

All the Gen 1 V4s have identical length intake funnels.. but some of the carb setups have richer jets and needles at the rear carbs

 

I had a Heck of a time getting one of the mounting screws out.. makes me think it was that way from the factory.

 

So weird that there's so much conflicting information about the orientation of the intake funnels..

 

**I wish Honda would be able to give info on this subject**

 

On mine there was a painted yellow dot on the #2 funnel and the tray beneath it.

 

I replaced the funnels in the position they were removed

 

Sent from my SM-N950U using Tapatalk

 

 

 

 

 

 

[Grum]

6 hours ago, jstehman said:

So bizarre about the intake funnels!

 

All the Gen 1 V4s have identical length intake funnels.. but some of the carb setups have richer jets and needles at the rear carbs

 

I had a Heck of a time getting one of the mounting screws out.. makes me think it was that way from the factory.

 

So weird that there's so much conflicting information about the orientation of the intake funnels..

 

On mine there was a painted yellow dot on the #2 funnel and the tray beneath it.

 

I replaced the funnels in the position they were removed

 

Sent from my SM-N950U using Tapatalk

 

 

 

 

Well at least you had No2 correct with a short funnel.

The way I see it, is its all about fine balancing of the air intake pulses, or something like that!

Your engine firing order is 1-3-2-4.

So. Between 1 to 3 = 180deg of rotation and the funnels are a Long to a Short.

Then 3 to 2 = 270deg of rotation and the funnels are a Short to a Short.

Then 2 to 4 = 180deg rotation and the funnels are Short to a Long.

Then 4 back to 1 = 90deg rotation and the funnel are Long to Long.

 

So now you can see that the greatest crank angle between firing is 270deg having the two Short Funnels AND the smallest crank angle between firing is 90deg having the two Long Funnels.

The other two firing angles are both 180deg and have a Long and Short Funnel combination.

Cheers.

Service manual picture also shows the funnel length and position info.

 

 

[Mohawk]

Rear cylinders on all V4's run richer because they run hotter than the front bank due to less air flow over the rear bank. 

[jstehman]

Looking back at my sync, I was unsure if the PAIR valve connector being unplugged.

 

Is it better to have blocked off the valve at the cylinder head, or just unplugging the solenoid have the same effect?

 

Also I noticed the engine seemed to run cooler since the sync? Temp gauge used to read 190-220 after a good hard throttling ride and come down to 25-35mph and she's running 180ish? Kinda weird

 

Sent from my SM-N950U using Tapatalk

 

 

 

 

[Grum]

4 hours ago, jstehman said:

Looking back at my sync, I was unsure if the PAIR valve connector being unplugged.

 

Is it better to have blocked off the valve at the cylinder head, or just unplugging the solenoid have the same effect?

 

Also I noticed the engine seemed to run cooler since the sync? Temp gauge used to read 190-220 after a good hard throttling ride and come down to 25-35mph and she's running 180ish? Kinda weird

 

Sent from my SM-N950U using Tapatalk

 

 

 

 

Really don't think the PAIR system has much of an effect. I've had good results from either blocking the PAIR hoses or just leaving the PAIR system as it is.

The PAIR solenoid is a normally Open device so when energised the air flow to the exhaust ports is Closed off. Not sure at what state the valve is at idle, open or closed?

In other words, just unplugging the electrical connector of the valve will certainly ensure air is available to the system. 

It would be easy just to block off the air inlet hose from the air filter housing to the PAIR Valve, that would do the same thing as blocking off both reed valves.

[Mohawk]

The Pair system has NO effect at idle, it is only activated during overrun when you shut the throttle. 

[Grum]

6 minutes ago, Mohawk said:

The Pair system has NO effect at idle, it is only activated during overrun when you shut the throttle. 

Strange why Honda would suggest blocking the reed valve air inlets while doing a SV Synch.

Must admit my last SV synch I never bothered with the PAIR system disable per the manual.

[Dutchy]

3 hours ago, Mohawk said:

The Pair system has NO effect at idle, it is only activated during overrun when you shut the throttle. 

And after a few years the will be clogged up anyway.

I asked my dyno guy if I should have  PAIR blocked off on my RC51. He told me not to bother as per the above.

If I insisted, he would do the work and charge me gladly he said 

[jstehman]

I'm very impressed how the sync darn near fixed the jerky small throttle openings. It's now possible to creep around in first and second gears without the bucking. Shifting gears is much smoother as well.

Sent from my SM-N950U using Tapatalk

[MisterBill]

Hi JSTEHMAN,

I have the same motorcycle ('07 VFR800 RWB), bought in '08. I also have the same problem with surging at idle. It just started this year. I was going to look into it this week. Excellent article and assistance from everyone.  Thanks, will save me a lot of time.

 

[ducnut]

Had a friend, and longtime Honda tech, sync mine, a couple weekends ago. It definitely smoothed out the low-speed running of my 5th Gen. In a few weeks, I’m headed to another friend’s shop for a tuning touch-up, after the newly added VFRD header.

[Warnzie]

So, this topic is about to get interesting. You may of seen from my posts ive been having a few low idle problems with the odd stumble since filling up from a dodgy servo. Hopefully it just some left over water in my tank and the treatment im using will evaporate it. So to cut to the chase, i thought i would do my starter valves and to check for any vacuum leaks whilst i was there, so i could at least eliminate a set of problems. My 2011 VFR has only had 2 owners, myself and my brother who had it as new. The airbox, apart from replacing a filter has never ever been touched. To my surpise while i was with my mechanic, watching him doing the work / sync - best way to learn;) the velocity stacks were not staggered!!! The 2 smaller stacks where at the front (left and right) and the longer stacks were at the rear (left and right). This bike has never been touched so this is how it has come from factory. Now looking at the service manual it definitely shows a staggered layout.....my thoughts on this as some are finding their stacks the same as mine from factory, are 2006+ models different to whats in the manual??? Did the 2006 update - which really was only minor adjustments to the vtec transitioning mean they went to a none staggered approach with the stacks???

 

Only other explanation would be Mr. Bonzai at the factory at the time got a little confused whilst on the factory line??????? 

 

Whatever the case, my 2011 from factory didnt have the stacks staggered???

[Grum]

Glad you have confirmed that it was bad fuel or water condensation that has caused all your issues. Good news.

 

It's very interesting that your funnels where incorrectly installed from new, must admit I'm surprised this could happen, certainly not impossible I guess.

Definitely no changes from 2006 onwards as the funnel length and position are relative to crank angles and firing order, and that has not changed. Even for the 8gen 2014 onwards it's the same as per 6gen. It appears the short/long funnels came in with the 6gen from 2002 onwards.

 

Wonder if there is any factual evidence as to the importance or non-importance of the staggered short/long intake funnels?

 

So did the mechanic install the funnels to their correct position? And what was his thoughts?

[Warnzie]

37 minutes ago, Grum said:

Glad you have confirmed that it was bad fuel or water condensation that has caused all your issues. Good news.

 

It's very interesting that your funnels where incorrectly installed from new, must admit I'm surprised this could happen, certainly not impossible I guess.

Definitely no changes from 2006 onwards as the funnel length and position are relative to crank angles and firing order, and that has not changed. Even for the 8gen 2014 onwards it's the same as per 6gen. It appears the short/long funnels came in with the 6gen from 2002 onwards.

 

Wonder if there is any factual evidence as to the importance or non-importance of the staggered short/long intake funnels?

 

So did the mechanic install the funnels to their correct position? And what was his thoughts?

Well, i hope this is the issue as it hasnt done it again since...but as with all these intermittent probs, it may just rear its head again. To be on the safe side i will do the earth mod at the front of the bike to eliminate another possibility, but also for my own confidence as it really is a problem that will come along at some stage!

 

Well, my mechanic did see the service manual and admitted they certainly weren't according to the manual, but conceded if it has been running fine since ive had it and it from factory just replace as was? Im very curious about this as it seems alot of us have them not per manual and they haven't been touched before??? on a lighter note, got everything synced up and to my surprise only one valve was out a touch, the rest pretty good;) and no vac leaks so that's confirmed that

[jstehman]

I went back under the tank to re-arrange the funnel placement.

Figured while I was there, let's check the valves again to be sure.. couple turns of this one and that one and good to go.

Upon removing the hose from the sync tool, I pulled off the vac line from tb#1! Wayyy too easy to pull those lines off!

13 year old vac lines being baked in the Vee of Honda are nice and brittle. I found a section of correct vac line at my dealer, enough to replace all 4 TB lines and the MAP sensor line and probably the vac line for the flapper for about $10

Next time I'm down I'll be changing those.

Sent from my SM-N950U using Tapatalk

[ducnut]

When I had mine down to the frame, I replaced every hose except the 4 with the tight 90° bends, because they’re molded. A company like AS3 could probably make those. 
 

Blue are FPR, red are MAP, and black are the TB vacuum hoses.