Throttle Body balancing

I don´t think so, because in Beetle map the O2 sensors are switched OFF.

Side question on this same topic ...

So if a GRiSO runs great, owner is happy happy with all running performance ... any real need to check this?

I just did my 900 mile first service, bike runs awesome so I kind of skipped the throttle body balancing part.

Hello, i have made a camshaft modification, and adjusted the throttle valve and TPS as mentioned in this topic, but still i have higher revs while idling, when i start the engine, it goes directly to 2000 rpm. after 15 seconds it falls back to 1400, but the early 1100 it does not do that anymore.: i was wondering by changing the camshafts with roller types, is there a change in valve lift, or another speed in lifting or closing that explains why the idling revs are so high ? for the rest it seems to that fuel consumption is lower from 6.3 ltr/100km and now its about 6 ltr/100 km. it gives more backfiring noise when closing the throttle, and acts a little bit more nerveuce on the throttle engagement. For the rest its still a great bike to drive. Greetings Jos

What year model?

Josv. I have a Beetle map in my 2013 GRiSO and when I start it, it sometimes (not always) goes straight to around 2000, 2500 rpm and then drops down to around 1500 and then again down to 1100. It usually only happens when the engine is warm though.

Hello Pete, i have a GRiSO from 2009 with 41000 km. with K en N filter and Akrapovic exhaust, i noticed that the air bleed valves were open while adjusting the TPS etc. i was sure that i did make a good job by cleaning the surfaces of the air intake gaskets, and perhaps i have to check the gauges ? Gr. Jos

Get rid of the K&N, it does nothing but upset things. The bike will require remapping. The factory GRS8V03 map is the last factory GRiSO map, it's OK but pretty pedestrian. Dunno if Mark has anything suitable for a Krapovic pipe? Has it got a dB killer? If not stick one in. The 8V does not like an open pipe.

Pete

wyno wrote:

Josv. I have a Beetle map in my 2013 GRiSO and when I start it, it sometimes (not always) goes straight to around 2000, 2500 rpm and then drops down to around 1500 and then again down to 1100. It usually only happens when the engine is warm though.

Exactly the same with my 1100 GRiSO. When warm, when I start it goes to 2000 and then back to normal after few seconds.

usedtobefast wrote:

Side question on this same topic ...

So if a GRiSO runs great, owner is happy happy with all running performance ... any real need to check this?  

I just did my 900 mile first service, bike runs awesome so I kind of skipped the throttle body balancing part.    

+1...looking to buy my first GRiSO but seems a bit high strung vs the V7III Milano I currently own (and will keep). Is this a factory recommended maintenance item with a set interval or just an enthusiast's way of fine tuning performance?

Thanks...

"Highly strung" isn't how I'd describe it, but the 8V is sensitive to a misbalance, especially the GRiSO with the asymmetric exhaust.

If you feel your bike is running OK, no one here will take offence if you don't balance your TB's at the first service, but you're really doing yourself a disservice if you don't. A well tuned 8V is a lovely thing, and simply can't be compared to a single throttle body V7 engine.

So, assuming the TB's are balanced at the first service, how long should the adjustment be good for?

Thanks.

Theoretically a long time. Having said that if the valve clearances are changed, even slightly, it affects the cam timing, (Well, the valve timing to be accurate.) and therefore the breathing so the procedure should be repeated. It's so easy I can't see any reason not to.

Pete

If you are looking for 6mm hose nipples look no further than a couple of 6mm grease nipples.
File the tip off the threaded end to let out the spring and ball.
Note:
If you make your own oil filled manometer you really need to finish off the hoses with a short piece of rubber as the plastic will get soft when warm and drop off. I did just use a band of heat shrink around the plastic for a while but rubber hose is better.

I use a couple of Amal needle jets. Screws straight in, and fits the hoses on my Twinmax balancer perfectly.

OK, so I finally got what I needed to connect to Guzzidiag and got it to work and can set the TPS etc.
Now, I'd like to be able to check and tweak (if needed) the throttle bodies. Plan to buy a Morgan carbtune. I checked the TB's with a friend who used to have a GRiSO and they were looking pretty good so we didn't do anything but that was 2 years ago.
I've read the great tutorials and here are some questions I have; does the position of the air bleed valves effect the balancing? For example if I check to see if they are open or closed today, can I screw something up? And, when I go about checking them and go thorough the procedure (where they are closed to start) do I need to open one at the end? and how much etc. I read Pete's write up at the beginning of this thread and looked at Beetle's pictures (invaluable) but no mention about opening one back up at the end of the procedure.
Many thanks.

I'm sure the threads explain it like here [You must be registered and logged in to see this link.] .

Basically you open ONE of the bleeds at the end of process to balance the vacuum at idle (if they are matched then you don't )

Thanks Paul. I guess I missed this from Pete's info:

"Re-start your engine and look at the manometer. Whichever side has the highest manifold depression use the air bleed on that side to lower it until both sides are running identically."

My Morgan carbtune showed up this week. Is it possible for me to check the throttle body sync without having to close both air valves? So, can I just check them the way they are in hopes that they are still good from last time?
Thank you.

Well yes, you can check it but what's the point if you can't complete it? It's a 15 minute task. Do you have Guzzidiag working John?

Hi Pete,

Yes I do. I was planning to follow your procedure. And I’ve been able to reset the TPS. I’m just a virgin to all of this and don’t want to screw something up went it seems like it’s running fine.

Got it done this morning. Never would have been able without this site and “youse guys”.
I’m hours from the closet supposed Guzzi dealer. Probably Guzzi Steve is closest at 4 hours.
Many thanks again.

He's been known to make house calls (a.k.a. road trips).



(Not volunteering you Steve, just impressed that you will travel for wrenching).

Pete

Pete Roper wrote:

Whatever form of manometer you use it connects to the two ports on the manifolds just forward of the throttle bodies. In the US these have small spigots that attatch to the charcoal canister/vapor recovery system. In most markets they are simply blanked off with dome head 6mm screws with alloy washers.

The only step you missed is after you have done the high speed balance and re-set the TPS you then balance at idle by opening the air bleed on whichever side has the highest manifold depression until both sides are equal.

Pete

PS. An oil filled manometer will work and can even be reasonably accurate as long as the balance isn't initially so far out as to allow the fluid to be sucked into the engine. The thing that I always find a trifle strange is that anyone who can afford a $20,000 motorbike would baulk at paying a few bucks to get a simple, accurate, clean and risk free tool to tune it!

Thats how rich f*ckers become rich by being tight f*ckers.
Can I use two guages off a 4 analogue gauge setup as us ex jap owners have lots of these things laying around unused?

[You must be registered and logged in to see this image.]

No. That's why tight fuckers always ride around on poor running, badly tuned pieces of shit.

Yes, a pair of dial gauges are fine although most of them tend to be less than accurate so cross check them.

Dial Gauges are notoriously inconsistent. I had about 6 at one stage and found two that matched, two that were pretty close. The other problem is that they pulse badly. I found that by soldering up the aperture into the gauge and then drilling a tiny hole (say 0.2 mm dia) the pulsing is much diminished. Also cramming paper towel in the hole helps but it needs to be secure for some reason and is a "desperate and dateless" solution.