Engine Rebuild? What exactly does it entail? or Replace with Wreck Engine.

[ab]

So as my monster 620cc 2004 is just chugging along and not purring as it used to at 46K miles, I was wondering what exactly does engine rebuilding entail?  At 25K, I had replaced my pistons with ferracci kit.  Is that considered rebuild?  Can some knowledgable person here explain it to me. 

is it cheaper to rebuild or buy a low mile engine from a wreck?

Ideally a higher cc engine would be great?  Has anyone in the forum done it?  S4R type of deal or 749.

Looking for a winter project and plan and see if it is within the budget.

Thanks

[Raux]

wow. i've seen bikes on here with a lot of miles, what are you doing to yours or not doing that you think it needs rebuilding again basically?

how much was the ferracci setup? I would  think you would need to do as least as much for a good refreshing if it needs it.

[1KDS]

It would be a hell of a lot easier to go with a bigger 2V motor than a 4V, ie 900 or 1000DS.  SBK has a different case width at the swingarm pivot, S4R is doable but more of a headache than a 2V.

[Howie]

Depends what's wrong, first step is an evaluation.  You may just have a tuning problem.

[ab]

Yep, I contacted my mechanic about rebuilding it.  When I inquired about why she is chugging and not purring, he suggested that the engine may be tired.  Mind you, I ride the crap out of it still.  He always said, take it out in the back and shoot it  L
LOL.

I may consider 1000ds or 900cc if it is easier to work with the existing setup.  I need to find more info or anyone that may have already done it.

OR

I guess get it tuned this winter and see if she gets some life back into her again.  Last valve adjustment was at 30K and is overdue.

off-topic.
In the meantime, the stupid Triumph S3 has been in the shop about 3 weeks now and had to have the engine dropped to fix a bushing pressed into one of the gears started to move out of position and make the trans. tight.  Another couple of weeks without the S3.  I already put 4K miles on it since April.  I got to say that S3 is awesome for the twisties but man if you not careful comes up on you so easily.  So easy to lean, really easier than the dm620 believe it or not.

I am starting to get reputation with friends that I have no luck with bikes.

[Howie]

I would seriously suggest a different shop if your mechanic cannot give you specifics.  Low compression?  Leaking valves?  The engine may be tired is NOT a diagnosis.

[El Matador]

So as my monster 620cc 2004 is just chugging along and not purring as it used to at 46K miles,

 

Last valve adjustment was at 30K and is overdue.

This right here is your problem. I'm surprised the engine hasn't blown up yet.

[ab]

True.  She has had all her maintainance at all intervals.  A bit late this time.  Reason, my Triumph is in the shop so I need the duc and mechanic is way too busy to squeeze in the duc   .  She will get some loving soon.  Right after this Saturday long ride to South Eastern Ohio twisties  :-)

I tightened the spark plugs, that seemed to have helped last night.  She was not backfiring like 4th of July fireworks now.

(sick of this - the side panel broke off again. wtf)

This right here is your problem. I'm surprised the engine hasn't blown up yet.

[ab]

Still waiting on explanation on what engine rebuild entails exactly ?  Can someone knowledgeable break it down for me ? 

Thank you

[1KDS]

Usually its just a topend check/rebuild.  Pistons and rings, tolerance checks etc..  As others have said you probably don't need a rebuild and just need to get the valves adjusted and motor checked over.

[Howie]

Re manufactured is rebuilding an engine and replacing all wearing components, in short, all except the block (specific to your bike) cases are either replaced or machined.

Overhauled is replacing all worn components in the engine.

Rebuilt is somewhere between re-manufactured and overhauled, all common wear components are replaced or machined.

On a Duc engine 1KDS about sums it up, since going into the lower end is usually cost prohibitive.

Again, if your compression is good, there are no unusual noises from the engine internals, an unusual amount of metal chunks of metal on the screen, excessive smoke from oil burning or excessive oil consumption you do not need a rebuild.

[ab]

Re manufactured is rebuilding an engine and replacing all wearing components, in short, all except the block (specific to your bike) cases are either replaced or machined.

Overhauled is replacing all worn components in the engine.

Rebuilt is somewhere between re-manufactured and overhauled, all common wear components are replaced or machined.

On a Duc engine 1KDS about sums it up, since going into the lower end is usually cost prohibitive.

Again, if your compression is good, there are no unusual noises from the engine internals, an unusual amount of metal chunks of metal on the screen, excessive smoke from oil burning or excessive oil consumption you do not need a rebuild.

Thanks for the info.

Ouch, I am burning oil fast.  To the point where I have started carrying quart of oil on the back to top it off.   She is going for maintenance as soon as my Triumph comes out from maintenance work. 
Sorry what is "1KDS" ?

[Howie]

Thanks for the info.

Ouch, I am burning oil fast.  To the point where I have started carrying quart of oil on the back to top it off.   She is going for maintenance as soon as my Triumph comes out from maintenance work. 
Sorry what is "1KDS" ?

I don't know what 1KDS is, but I assume he is human since he is a DMF member.

Burning oil fast?  If the nikasil took a crap look for a used engine.

[badgalbetty]

if you dont know what nikasil is it is the coating on the cylinder lining.
Engine rebuilds usually include the following on most engines: Complete teardown,cleaning and inspection. All wearing surfaces must be within the MFR's specifications.
Commonly done are grankshaft regrinds, con-rod big end resizing, and small end re sizing with new bushings fitted, new main bearings, new oil pump, Cylinder liner bored and oversized pistons fitted. Cylinder head machined flat if needed, new valves, guides and seats cut if required.New camshafts and related valve train depending on wear.Al transission parts inspected for wear ,bushings replaced as needed, shift forks checks for starightness and wear, Clutch usually gets new plates if needed and all new seals gaskets etc upon reasembly.
An engine rebuild is about 15 hours labor.........so figure $1500.00 before you buy any parts.
At least that has been my experience. I was a mechanic back in the 1980's for Suzuki.
BGB

[1KDS]

Basically, if you're burning oil then you have oil in the combustion chamber.  This could be caused by the cylinder wall coating being worn down of the piston rings not sealing.  You are looking at a top end rebuild with new jugs or a new (to you) motor and ancillaries.