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Discussion Starter #1 (Edited)
Hello,

My name is Jeroen and I'm from the Netherlands. I have been reading some threads over here for a while but haven't made a lot of posts.

I wanted to share the problem that occurred on my f4 750 EV 02.
A while back I started to hear a slapping/ticking noise from the engine. After some research I found out it had something to do with the cam chain. Manually gave the tensioner a slight push while rotating the crank by hand. The tensioner extended one tooth. Started the engine and the slapping sound seemed to be gone.

Had my doubts about the old tensioner and decided to buy a new cam chain tensioner. After installing the new tensioner I checked the timing and it was fine.

Have been riding for a couple of 100 km like this. The sound it made was consistent and didn't change over time. Have been watching (listening) some youtube videos of other 750's to listen if they made the same sound and they did.

But the first of July has been an unforgettable day.... In a bad way.
We were passing a small village with 30-40 [km/h], low revs. I started to hear a rough noise from the engine, pulled my clutch and I could barely hear it anymore. Let the clutch go again and the sound continued. Wanted to stop but before I could do anything a scraping/slapping noise followed by a soft tick. Engine died, end of story.

Took the bike apart at home.... what I saw was rather a confirmation of what I thought than a surprise. At least 2 bent inlet valves.


Still had to find the cause of the problem.
-Timingchain was in one piece
-Timing fine
-Sparkplugs, fine

Everything was fine till I saw this....:wtf:



What I think happened:
The bolts form the inletcamshaftsprocket came loose.
Allowed some play in the sprocket which eventually snapped the bolts.
Timing gone bad
Valves hit the piston
Resistance from the valves on the piston made the sprocket fully rotate on the camshaft
Inlet valves didn't open anymore, engine died

Question remaining... what is the smartest thing to do.
Fix this engine or search for a replacement engine?
 

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Hi Jeroen,
Sorry to hear that, my best advice is as follows, take the head off and inspect the pistons and remaining valves for damage, I suspect the damage is going to be too expensive to fix, the gaskets set is costly as is.

A replacement engine may be a cheaper option, if you stretch your budget maybe a 1000cc conversion, but these donor engines are getting harder to source.

Good luck with your engine, hope its not so bad.

jimboF4
 

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Discussion Starter #3 (Edited)
Hi Jeroen,
Sorry to hear that, my best advice is as follows, take the head off and inspect the pistons and remaining valves for damage, I suspect the damage is going to be too expensive to fix, the gaskets set is costly as is.

A replacement engine may be a cheaper option, if you stretch your budget maybe a 1000cc conversion, but these donor engines are getting harder to source.

Good luck with your engine, hope its not so bad.

jimboF4
Is it an easy job to take the head off while the engine is still in the frame?
I haven't really got a clue what the price of a head rebuild would be.
Probably the total costs depend on the pistons and other 6 valves, which are visually fine but that doens't guarantee a thing.

What are the main components required for a 1000 conversion?
Engine ofcourse, larger injectors, different eprom
 

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May not be too expensive. Valves, camshaft bolts, head gasket...depends on what you find.
I have an entire head assembly I bought on a whim when I got my SPR. Just to have spares, but it is an EVO head, not SPR, so doesn't have the Ti valves my engine uses.
I would sell it to you for what I have in it, but shipping to you may be a lot.

You should pull the head off and see just what the damage is. Look carefully at the valve guides as they may have been cracked when the valves bent. Besides the guides, the seats would be a concern. If seats and guides aren't damaged and you only need a handful of valves and some gaskets the repairs will not be too bad.

CAG may or may not have some engine bits like valves. He usually didn't part out engines, but can't hurt to ask him.

At least the valves are intact. Had a valve head come off the stem you would be looking at much worse damage.

Good luck.
 

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Oh...I believe the engine will need to be dropped to get head off. Not that hard a job really.
 

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I would drop the engine, much easier than you think, look in the maintenance thread and get a copy of the manual from Donsy's site.

You will need to get the head to a competent bike machine shop and get all the valves checked, if it is only two then buy new from MV, you may have a good wait on your hands, check the cams for wear and find where the bolt has gone. You will need to price up all the parts and gaskets and work. That will then be the decider.

Don't think about the 1000cc conversion for now, if you do go that route there are differing bits you will and won't need depending on what year engine you find, even a Brutale 910 etc can go in.

jimboF4
 

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Discussion Starter #7
May not be too expensive. Valves, camshaft bolts, head gasket...depends on what you find.
I have an entire head assembly I bought on a whim when I got my SPR. Just to have spares, but it is an EVO head, not SPR, so doesn't have the Ti valves my engine uses.
I would sell it to you for what I have in it, but shipping to you may be a lot.

You should pull the head off and see just what the damage is. Look carefully at the valve guides as they may have been cracked when the valves bent. Besides the guides, the seats would be a concern. If seats and guides aren't damaged and you only need a handful of valves and some gaskets the repairs will not be too bad.

CAG may or may not have some engine bits like valves. He usually didn't part out engines, but can't hurt to ask him.

At least the valves are intact. Had a valve head come off the stem you would be looking at much worse damage.

Good luck.
Thanks a lot for the quick response!
Yes, it could have been a lot worse. Valve guides of the 2 valves on the picture are both cracked.
 

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Discussion Starter #8
I would drop the engine, much easier than you think, look in the maintenance thread and get a copy of the manual from Donsy's site.

You will need to get the head to a competent bike machine shop and get all the valves checked, if it is only two then buy new from MV, you may have a good wait on your hands, check the cams for wear and find where the bolt has gone. You will need to price up all the parts and gaskets and work. That will then be the decider.

Don't think about the 1000cc conversion for now, if you do go that route there are differing bits you will and won't need depending on what year engine you find, even a Brutale 910 etc can go in.

jimboF4
Was just curious about the 1000.

Thanks, will take a look at it as soon as I've got some time.
I'll keep you guys up-to-date in this thread.
 

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oof, that's a tough one to take. Weird place for an engine failure for the Agusta motors. Hopefully you can get away with a a head rebuild for cheap.

Don't know if i would have what you need, but i do have a bunch of valves(25mm,29mm,30mm) should you be able to renew the head. Sounds like the speed was slow enough that you didn't damage the piston(s) to bad.
 

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Discussion Starter #11
oof, that's a tough one to take. Weird place for an engine failure for the Agusta motors. Hopefully you can get away with a a head rebuild for cheap.

Don't know if i would have what you need, but i do have a bunch of valves(25mm,29mm,30mm) should you be able to renew the head. Sounds like the speed was slow enough that you didn't damage the piston(s) to bad.
Thanks, I'll remind that.

What you are saying was the thing I still wanted to ask.
Is this a common known failure?
I quess not, just bad luck....
 

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A swap to a 1000 engine would also require the correct wiring loom and matching 1000cc ECU either 1000s or 1000R, 312R

Does the 750 header bolt up to the larger motors? If not, then he'll need exhaust too.

The good thing about a rebuilt head is he can get the head shaved, and/or use a thinner headgasket to bump compression. Not only that but could get some light porting done at the same time. And wondering if 1000cc cams fit the 750 motor??? Might be able to get some bigger lift and longer duration from the larger cam if its not to much trouble to fit em.
 

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Thanks, I'll remind that.

What you are saying was the thing I still wanted to ask.
Is this a common known failure?
I quess not, just bad luck....

I haven't been around agusta for as long as some others on this site, but this is the first one i've come across that failed like yours. Guessing you where just unfortunate enough to get a motor with a bad bolt, or someone at the factory was sloppy that day when assembling that motor.
 

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Discussion Starter #14
Does the 750 header bolt up to the larger motors? If not, then he'll need exhaust too.

The good thing about a rebuilt head is he can get the head shaved, and/or use a thinner headgasket to bump compression. Not only that but could get some light porting done at the same time. And wondering if 1000cc cams fit the 750 motor??? Might be able to get some bigger lift and longer duration from the larger cam if its not to much trouble to fit em.
In case I'm going to fix this engine, which seems like it if I won't find anything badly damaged underneath the head, the head will be completely overhauled.
 

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Discussion Starter #15
I haven't been around agusta for as long as some others on this site, but this is the first one i've come across that failed like yours. Guessing you where just unfortunate enough to get a motor with a bad bolt, or someone at the factory was sloppy that day when assembling that motor.
It has done about 35k [km] Done the maintenance myself since I bought the bike but never touched those bolts. Can't imagine that it is a standard precedure to torque check those bolts.
 

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Discussion Starter #16
Could be complete blindness but I can't find a thread about removing the engine from the chassis.:errr:
 

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Well... I don't know if it is an option for you, but you can loosen the frame and then lift the complete front end to work on it. If that works... I am sure that someone here knows more than I do :)
 

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Download the manual for the bike from the sticky at the top of this section, listed on Donsy's site.

It is a very easy job, to drop the motor read the manual and follow the steps, if I can do it so can anyone.

jimboF4
 

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Discussion Starter #20
Already had a look at the manual. Guess you are referring to the FRAME section where they "remove" the engine bij taking away all the other components?
 
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