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I picked up a 2002 SV650s last week for $900 and I knew it needed work. It doesn't idle, runs like crap and won't rev over 7000. It sat for a while and I know I'm going to need to rebuild the carbs. I took it to a shop so they could go over it and check everything. They told me yesterday that the rear cylinder has 210 and the front has 145.

Basically, the shop said they could do a valve adjustment and see if that fixes the compression issue. If it does then I can move on to the carbs. Are the chances fairly high that it's just the valves? I'm unfamiliar with SV's in general so I don't know if that's a common issue.

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with the front down that far I suspect it needs more than a valve adjustment
 

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Do a Leak down test. It will show exactly what your problem is. Easy to do, basically takes an air chuck that screws into the spark plug holes and an air compressor. It's nice to have the gauges but you can tell a lot by listening for the air leaks.

Mad
 

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Would it be burning oil if it was the piston rings? It's not smoking at all.

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Also, I just spoke with the shop. They're thinking that if the valves are too tight it would be causing this. Makes sense but I would think the valves would get looser over time. Maybe I'm just not familiar with how they wear.

I'm really hoping it's just the valves because otherwise I'm looking at new piston rings or worse. Which the shop said would be $2000+. I may just dive in and do it myself at that price.

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With a bike of that era and price range, it's probably cheaper to throw the bike away and buy something newer vs paying a shop to do everything for you.

DIY is the way to go.

Not trying to be negative, just realistic.
 

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You could work out whether it is the piston rings yourself with a dry and wet compression test. You will need a compression tester (a cheap one is only about £20 and would be perfectly adequate). Test each cylinder as they are now first (should be about 150PSI per cylinder - about 10.5:1 CR), then squirt a slug of 10W40 in through the plug and repeat the test. The oil forms a temporary seal around the piston, so if the CR suddenly increases in either cylinder then the piston rings are at fault (re-bore, pistons and rings required). If the CR doesn’t change appreciably then it is the top end at fault: either the valve clearances or valve seats.

You could easily check the valve clearances yourself - it is a trivial job (the clearances do tend to tighten up with age as the valves wear into the valve seats). That will tell you whether the issue is with the clearances or the valve seats. If it is the valve clearances you could do that job yourself - just be methodical, it is a fiddly rather than difficult job that involves taking the cams off to access the followers, measuring the shims and replacing them with correct ones. You could do that much in a day, get the new shims by mail and put it back together another day.

If the issue turns out to be the valve seats or the piston rings then you will have to work out for yourself whether it is worth fixing or not. Either way you would need a machine shop to re-bore the cylinders or re-cut the seats plus lots of expensive engine parts - and after all that you will still have to adjust the valve clearances (as above).

Junkie is absolutely right: if you have a garage do any of the work listed above it will cost you more than you paid for the bike, and in the case of piston rings or valve seats far more. You would never recoup the cost of paying a workshop to do any of it, so that leaves either doing it yourself (plus the boring or re-seating) or scrapping the motor for parts - and perhaps looking for a replacement used engine.

If you leave the bike at a garage for more diagnosis the costs will very quickly escalate - and you still may get to the point where it is not worth fixing but you have spent $1000 finding out. I’d suggest doing the dry and wet compression test (cost about $25 and you get to keep a useful compression gauge afterwards) to eliminate the bottom end problem, and then check the valve clearances to see if that is the issue. Those two jobs will only take an hour or so if your time and cost a few gaskets to put it back together. At that point, and having worked out the cause by elimination decide whether to fix the issue yourself or start looking for a better motor - even if you do it yourself I don’t think either rings or valve seats are worth fixing on a $900 bike unless you just want a challenge.

Good fortune,

Alan




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You could work out whether it is the piston rings yourself with a dry and wet compression test. You will need a compression tester (a cheap one is only about £20 and would be perfectly adequate). Test each cylinder as they are now first (should be about 150PSI per cylinder - about 10.5:1 CR), then squirt a slug of 10W40 in through the plug and repeat the test. The oil forms a temporary seal around the piston, so if the CR suddenly increases in either cylinder then the piston rings are at fault (re-bore, pistons and rings required). If the CR doesn’t change appreciably then it is the top end at fault: either the valve clearances or valve seats.

You could easily check the valve clearances yourself - it is a trivial job (the clearances do tend to tighten up with age as the valves wear into the valve seats). That will tell you whether the issue is with the clearances or the valve seats. If it is the valve clearances you could do that job yourself - just be methodical, it is a fiddly rather than difficult job that involves taking the cams off to access the followers, measuring the shims and replacing them with correct ones. You could do that much in a day, get the new shims by mail and put it back together another day.

If the issue turns out to be the valve seats or the piston rings then you will have to work out for yourself whether it is worth fixing or not. Either way you would need a machine shop to re-bore the cylinders or re-cut the seats plus lots of expensive engine parts - and after all that you will still have to adjust the valve clearances (as above).

Junkie is absolutely right: if you have a garage do any of the work listed above it will cost you more than you paid for the bike, and in the case of piston rings or valve seats far more. You would never recoup the cost of paying a workshop to do any of it, so that leaves either doing it yourself (plus the boring or re-seating) or scrapping the motor for parts - and perhaps looking for a replacement used engine.

If you leave the bike at a garage for more diagnosis the costs will very quickly escalate - and you still may get to the point where it is not worth fixing but you have spent $1000 finding out. I’d suggest doing the dry and wet compression test (cost about $25 and you get to keep a useful compression gauge afterwards) to eliminate the bottom end problem, and then check the valve clearances to see if that is the issue. Those two jobs will only take an hour or so if your time and cost a few gaskets to put it back together. At that point, and having worked out the cause by elimination decide whether to fix the issue yourself or start looking for a better motor - even if you do it yourself I don’t think either rings or valve seats are worth fixing on a $900 bike unless you just want a challenge.

Good fortune,

Alan




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That's fantastic info! Thanks

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That's fantastic info! Thanks

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Beware the garage trying to persuade you to pay for the valve check and adjustment, it will be something like 4-6 hours labour (if adjustment is needed) plus a hundred dollars in parts (at dealer prices), so you might well have a $500 bill with no guarantee whatsoever that the issue will be fixed. The garage will have known exactly how to do a dry and wet test (which would have taken hardly any longer than the compression test it has already done). It may be looking for an open cheque from you whilst it fixes a whole load of things before finding the problem (and by then the bike may owe you $4000).

This bike isn’t worth much (and it wouldn’t be worth much more if fixed) but might make an interesting project if you are up for it - so get it back from the garage now and do the work yourself. As a general rule projects are never worth the cost and will take lots of your time. They can be interesting and satisfying though (and are a good excuse to buy lots of tools for your own garage).

Good fortune,

Alan


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Also, I just spoke with the shop. They're thinking that if the valves are too tight it would be causing this. Makes sense but I would think the valves would get looser over time. Maybe I'm just not familiar with how they wear.

I'm really hoping it's just the valves because otherwise I'm looking at new piston rings or worse. Which the shop said would be $2000+. I may just dive in and do it myself at that price.

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On some bikes, the valves, especially the intakes, tighten up over time. Check the clearances yourself. $2000 to replace the pistons and rings is silly. You can do the job yourself for MUCH less even if the cylinders turn out to be worn.

Mad
 

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On some bikes, the valves, especially the intakes, tighten up over time. Check the clearances yourself. $2000 to replace the pistons and rings is silly. You can do the job yourself for MUCH less even if the cylinders turn out to be worn.



Mad


Well, I can see how the garage came up with $2000 if the engine needs a re-bore, oversize pistons and rings. Suzuki will supply a +0.5mm piston set for about £200/cylinder, but I’ve just noticed an aftermarket 83mm big bore kit for about £330, which would make more sense. A gasket set would be £100 and it would be sensible to change the little end bearings at the same time, say another £50. The re-bore would be around £50/cylinder, so the total parts bill might be something like £600 plus say another £100 stuff that needs changing at the same time. £700 if the OP did the work himself (in dollars perhaps $800-900). I can imagine that a garage would charge for 2 days labour - easily £1000 here in the UK (but I’m out of touch with skilled labour rates in the USA). That would easily make $2000 in parts and labour, but you are right, the OP could do it himself for maybe half that in parts and services alone.

If the piston/rings/bore has failed, there would still be the question of why it has done so, and as the OP doesn’t know much about this bike that would remain an unknown. Even after re-building the top end he might find the original fault that led to the failure persists, so it would be some considerable risk.

Unless the OP really wants an engineering project (and he may) then I’d suggest the cost and risk of a piston/ring fix would exceed the value of an engine he knows very little about.

SV engines are generally quite bulletproof, so I’m wondering whether there is more to this one than meets the eye. It would be sensible for the OP to carry out the diagnosis himself, work out what is wrong and then assess whether it is worth fixing (all of which would be really good experience) before embarking on a re-build project.

I do hope the OP keeps us informed of his progress on this one. It would be nice if the issue were to be solved by a valve clearance adjustment (although if the valve clearances are far enough out to cause loss of compression I can’t help thinking the valve seats will need replacing). If he does decide to re-build the top ends (or even the whole motor) himself I hope he catalogues the project with photos and notes for us - that would be a fascinating thread.

I wish the OP good fortune and hope he will let us know how this project goes.

Alan


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Although I've done it some, I would much rather have a "bullet proof" used factory motor than one I had taken apart. Used motors go for around $6 to 8 hundred bucks, which would put him close to $2K to get it running right. Another $1K for the suspension upgrades all SV's need and it's $3K, assuming he does the work himself. Good motorcycles go for around $3K. Just sayin'
 

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Although I've done it some, I would much rather have a "bullet proof" used factory motor than one I had taken apart. Used motors go for around $6 to 8 hundred bucks, which would put him close to $2K to get it running right. Another $1K for the suspension upgrades all SV's need and it's $3K, assuming he does the work himself. Good motorcycles go for around $3K. Just sayin'


Spending $1000 on changing the suspension on a bike that cost $900 in the first place would be lunacy. The standard suspension on the SV is perfectly safe and adequate for the market it was designed for.


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Spending $1000 on changing the suspension on a bike that cost $900 in the first place would be lunacy. The standard suspension on the SV is perfectly safe and adequate for the market it was designed for.


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It all depends on what he expects out of his machine and what he plans on doing with it. If it's to be used as a commuter, basic transportation sort of thing then yeah, the worn-out price-point OEM suspension is perfectly fine. If, OTH, he wants to go fast, sport tour with gear, do track days and such, state-of-the-art suspension components will transform an SV. A competent rider on such a machine will be able to hang with anything out there. Just because it cost the OP $900 doesn't mean there's not a nearly perfect chassis/engine combination lurking within, there most certainly is. Aftermarket and hot rod parts can be sold off separately when the time comes to recoup some of the costs, but as a rule, motorcycles are poor investments. If you're looking for a return on your investment, stamp collecting is a far more lucrative hobby.
 

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It all depends on what he expects out of his machine and what he plans on doing with it. If it's to be used as a commuter, basic transportation sort of thing then yeah, the worn-out price-point OEM suspension is perfectly fine. If, OTH, he wants to go fast, sport tour with gear, do track days and such, state-of-the-art suspension components will transform an SV. A competent rider on such a machine will be able to hang with anything out there. Just because it cost the OP $900 doesn't mean there's not a nearly perfect chassis/engine combination lurking within, there most certainly is. Aftermarket and hot rod parts can be sold off separately when the time comes to recoup some of the costs, but as a rule, motorcycles are poor investments. If you're looking for a return on your investment, stamp collecting is a far more lucrative hobby.


... it is a pity the OP didn’t let us know whether he fixed the engine (this thread is 3 months old).

There isn’t much point arguing whether or not it is worth spending thousands of dollars on suspension upgrades for a $900 bike with a broken engine ... people may waste their cash in any way they please.


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