Would you buy an 8 valve with flat tappets?

[Jdcooper]

I charge 3-4hrs, any more is gouging.

If a "C" kit is required, the heads need to come off to install the valve shims. This complicates matters some.

[tris]

There are some 8V flat tappet bikes I like better than the later roller models.
A Griso SE for instance.

But I'm reluctant to purchase a flat tappet bike for obvious reasons.

Just gathering some thoughts on rather to purchase and what the cost would be to convert.

Mike

When I was looking for a replacement bike last year (Breva or Norge being the options) I decided to definitely NOT go for an 8V flat tappet bike following some discussion on this forum

The risk was too high for me to accept

[Wayne Orwig]

A new addition to the line of tin foil hats I sell.

[Waltr]

I would. Two caveats however:

Pre purchase inspection required by a dealer of your choice. If the tappets look like this:




Plus there is a service history? Say yes with the cost of the kit and labour factored in.


If they look like this:





Run away.

THAT IS UGLY!

[Waltr]

Has anyone actually found bearing damage as a result of failure?

[Wayne Orwig]

but who's really to blame.  a 2v is plenty fine. and will work for the next 50 years... but we need more power.  more.  the guzzi is weak.  a bwm spits in its face.  so lets add valves squeeze out a few more hp.

And that is why I'm keep hold of my 2004 EV with hydraulic lifters. No issues there.

Oh, wait!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[canuguzzi]

The flat tappet 8V bikes are projects. If you like projects, then maybe its something for you.

The efforts and costs to convert them vary as depending on the damage, more than just fitting the proper kit could be involved. All that info can be found on WG.

Getting the costs paid for vary according to the route you take. If the word "can't" is a favorite, then ante up and get the best deal you can.

So far, there are no similar issues with the roller 8V bikes.

When it comes to the extra power that the 8V bikes have, has anyone read any posts where owners where trying to lower the power output because the engines made too much?

[Wayne Orwig]

Has anyone actually found bearing damage as a result of failure?

Maybe. Maybe not.
Seriously, it gets complicated.

Looking at the photos that Beetle showed. That second photo shows a LOT of HARD metal missing. Some of that would have bypassed the filter on cold start. I would not buy that used unless it was the deal of the century and I fully expected to replace a lot of the bottom end, or even the entire block. See the edit below....

Mine looked worse then the first photo that Beetle showed. I pulled the rod bearings to inspect them, and basically I replaced them while I was there. The bearings measured fine using plastigage, and did not show damage due to contamination. But they didn't look new either. The crankshaft was pretty clean.

EDIT: I take back what I said a bit. The first photo below is my tappet. It had a bit more metal missing then I had remember from many beers/bourbons/merlots ago. The second photo is my rod bearing. The photo isn't all that great, but there is no obvious 'damage'. I suspect I replaced them because I had on the tin foil hat and was paranoid. And since I was touching them to inspect them, I replaced them.

[molly]

It is nice to see a bit of honesty and realism appearing on this subject, all we need now  the same from the dealers.

[beetle]

Just to confuse things a bit more, the 1200 Sport that had these:



Was found to have a pristine bottom end. That being said, I would still run away.




Pete's bottom end failed shortly after getting rollerized, but he's convinced it was from doing too many wheelies and starving the bottom end.

Now, what really concerns me is what some dealers consider a failure? If the tappets looked like the ones in Jdcooper's pic, a less experienced or somewhat ignorant dealer might think they're OK. That's a bit scary.

[pete roper]

Just to confuse things a bit more, the 1200 Sport that had these:



Was found to have a pristine bottom end. That being said, I would still run away.




Pete's bottom end failed shortly after getting rollerized, but he's convinced it was from doing too many wheelies and starving the bottom end.

Now, what really concerns me is what some dealers consider a failure? If the tappets looked like the ones in Jdcooper's pic, a less experienced or somewhat ignorant dealer might think they're OK. That's a bit scary.

This bike the sump was pristine but I didn't drop the rod caps. The crazy thing is it was the worst I've seen and I heard it coming from the end of King St! Sump was fine, and I've bunged the roller top end off Ralf's bike in as a stopgap and it's as quiet as a mouse!!! Go figure!

Pete

[Chuck in Indiana]

Welcome back, Pete. 
Oil filters are wonderful things..

[guzzisteve]

+1 on welcome back Pete!!!

[MotoG5]

I have one of the infamous early 12' Stelvios and rollered it myself. I will just keep it and ride the crap out of it until it fails or I do. Its just a motorcycle, there are plenty more where it came from and they are making new ones every day. As far as buying a older flatty, at the right price I would buy anything. If you want one get it, fix it and ride it. If you are totally adverse to doing any mechanical work or anything other than routine stuff get a new bike of your choice from a good dealer near home. Buying used is always a risk, life is a risk, take it from an old guy one phone call from your doctor can make your bike issues the least of your problems.

[Chuck in Indiana]

take it from an old guy one phone call from your doctor can make your bike issues the least of your problems.

  Absolutely. Life is short, don't sweat the small stuff.

[Yeahoo Whoyah]

If you want one get it, fix it and ride it

Yes indeed.   :1:
This topic seems like a modern day version of the chrome bore problem on the V700,750,850 Loops and early Tonti bikes.  Enthusiasts have been buying and rebuilding those old bikes for years.  I hope the flat tappet bikes get fixed instead of being scrapped, they deserve a better fate.  Current owners that want to sell must adjust their asking price downward to make it worthwhile. Recent eBay and CL prices don't seem to reflect that yet. 

[hauto]

Great thread,now I can buy a flat tappet Stelvio time bomb for  under 2K.

[hauto]

I posted this over in adventure rider in the stelvio thread.Really didn't get any feed back,hoping for more in WG     
"I want to move up from my Quota to a Stelvio.I've read all kinds of posts about flat tappets.After looking closely at the design I question it.The load of two valve springs on one tappet transferred down the rocker shaft.I don't believe the flat tappets ever had a chance to survive.I also think it was a cost consideration.The roller conversion came to be fairly quickly.Almost like the design was there and already produced.So lets say I buy and convert a flat tappet or buy a roller Stelvio,the extreme load of two valves on one tappet is still there.Will the failure now be in rocker box bearings(if it has bearings).Now talk me off the ledge and tell me how the earlier 4V mid cam motors do not seem to have this issue."

[Daniel Kalal]

...the extreme load of two valves on one tappet is still there...

Is it an extreme load?  I'll assume, then, that you've calculated (or measured) what the load is.  If so, what would you consider a moderate and therefore acceptable tappet design load?

[pete roper]

I posted this over in adventure rider in the stelvio thread.Really didn't get any feed back,hoping for more in WG     
"I want to move up from my Quota to a Stelvio.I've read all kinds of posts about flat tappets.After looking closely at the design I question it.The load of two valve springs on one tappet transferred down the rocker shaft.I don't believe the flat tappets ever had a chance to survive.I also think it was a cost consideration.The roller conversion came to be fairly quickly.Almost like the design was there and already produced.So lets say I buy and convert a flat tappet or buy a roller Stelvio,the extreme load of two valves on one tappet is still there.Will the failure now be in rocker box bearings(if it has bearings).Now talk me off the ledge and tell me how the earlier 4V mid cam motors do not seem to have this issue."

Yup, you're absolutely right, the whole design is terrible. Everything about it is beyond awful. If you were to buy one it would not only destroy itself but would climb in through your bedroom window at night and murder you in your bed!

Far better stick with the Quota.

[jackson]

Yup, you're absolutely right, the whole design is terrible. Everything about it is beyond awful. If you were to buy one it would not only destroy itself but would climb in through your bedroom window at night and murder you in your bed!
Far better stick with the Quota.

BWAAAAAAAAAAAAAAAAAAAAAAA HAAAAAAAAAAAAAAAAAA AAAA HAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAA

[beetle]

Here be trolls.

[beetle]

Thread, I spit at thee. From hells heart I stab at thee.

Die thread, die.

[hauto]

Forget I asked

[motoman]

I am sorry to say, I will not be buying another Moto Guzzi.

Current owner of the ill-fated Griso 8V, getting ready to rollerize.  Approx total cost P&L:  $1700

Previous Guzzi:  2003 California Aluminum.  Oh yeah, the 'Hydro Valvole'   How many recalls?  5?

Then Piaggio lowered the MSRP, thus destroying my resale.  Took a bath.

Sorry, Done for now.  If I can get this Griso right, I'll be happy.  But not going there again.   Too many Ultra-reliable bikes out there.

 

[Bulldog9]

To the OP, NO, not at this point, MAYBE 5 years ago, but not at the 10+ year mark. Plenty of roller 8V motored bikes out there.

I will never understand the issues over 4V/8V identification.

It is simple 4V motor means 2V head, 8V motor means 4V head.  As some as someone identifies head or motor, it is easy.

I have had two 'go's' at Guzzi 8V motors, a 1200 Norge and 1400 MGX,  I didn't like either, and far prefer the older 4V motors.  YMMV

[Motormike]

Not only would I, but I did.  Wanted a Tenni Green Griso so found a low milage one and did the roller swap myself.  The flat tappets had very minimal wear at 4000 miles.  Bike runs like a champ all these years later.  Like anything in life, you place your bets and takes your chances. 

[OldMojo]

Another zombie thread arises!

[Two Checks]

Inconsistencies.... like tappets vs lifters.
If your lifters are tapping anything you have a problem.
The tapping is done at the rocker arm/valve stem interface.   

[Kiwi_Roy]

Realistically do you think any Griso owner is going to let his bike be torn apart so you can look at the tappets? They might let you take the cover off if you were lucky.
I would buy a nice looking example knowing it needed rollers but only after I had determined that the appropriate kit was available and factoring in the cost.
I don't see how the metal can end up in the bearings, its scrubbed off the tappets, ends up in the sump, one trip through the pump and it should be safely locked in the filter.
It does have the possibility of destroying the pump however.
You can say on a cold start it might bypass the filter but wouldn't it have been trapped last time the bike was running hot?