curvy engine problem - Page 2 - SV650.org

03-06-12, 08:35 PM

Right ok, is it worth me taking the heads off, trying to turn it by hand and if fails againthen the cylinders? when you say big end what exactly do you mean, sorry im not the best mechanically minded person

yorkie_chris · 03-06-12, 08:39 PM

Never seen that before.

Pull head covers, check cams are looking pointing in sensible direction and chain is tight.
Pull side covers, check nothing is fouling.

Do all this first before you have to replace head gaskets again.

Fookin ell not the best mechanically but you managed to replace the cylinders, much further than many ever go...

03-06-12, 08:42 PM

ive had the cams back out along with the cam chain tensioners and the engine again locks after about half a turn in either direction.

its really bizarre, because it sounded perfect when it ran there was no knocks rattles or any suspicious sounds

rictus01 · 03-06-12, 08:43 PM

yeah you'll have the strip the heads off anyway, but try turning it over you've nothing to loose.

the bigend bearing is the other end of the conrod from the piston (the conrod has a smallend bearing holding the piston on, and a big end bearing attaching it to the crankshaft).

with the heads and the barrels removed, you should be able to give the piston a wiggle and feel for freeplay, if there is any, it shows the bigend is fubar'd

rictus01 · 03-06-12, 08:44 PM

just a thought, is the rotor on straight ?

03-06-12, 08:45 PM

Sorry what do you mean rotor? And again im not sure! and will have a check

rictus01 · 03-06-12, 08:47 PM

the alternator side (sitting on the bike LH side), has a rotor on the end of the crank, if this was to come off it could lock the crank, not a usual issue, but worth a look.

03-06-12, 08:52 PM

Right I will check that first then start stripping the heads etc. Would you reccomend taking the engine out completely and doing it on a bench? Any key points or parts to pay special attention to?

yorkie_chris · 03-06-12, 08:55 PM

You should be able to to find out what is wrong with it in frame.

As normal there is slight angular play in the conrod and slight side clearance too. However if you can feel any radial play like up and down movement in the rod then the big end's knackered.

03-06-12, 08:59 PM

Right ok, what if ive stripped the heads etc off and big end bearing seems fine but engine still locks, what would your next venture be?

03-06-12, 08:35 PM	#11
curvysvboy Guest Posts: n/a	Re: curvy engine problem Right ok, is it worth me taking the heads off, trying to turn it by hand and if fails againthen the cylinders? when you say big end what exactly do you mean, sorry im not the best mechanically minded person

03-06-12, 08:39 PM	#12
yorkie_chris Noisy Git Mega Poster Join Date: Apr 2007 Location: Halifax/Leeds Posts: 26,645	Re: curvy engine problem Never seen that before. Pull head covers, check cams are looking pointing in sensible direction and chain is tight. Pull side covers, check nothing is fouling. Do all this first before you have to replace head gaskets again. Fookin ell not the best mechanically but you managed to replace the cylinders, much further than many ever go... __________________ Currently Ex Biker Now rebuilding a 63' fishing trawler as a dive boat

03-06-12, 08:42 PM	#13
curvysvboy Guest Posts: n/a	Re: curvy engine problem ive had the cams back out along with the cam chain tensioners and the engine again locks after about half a turn in either direction. its really bizarre, because it sounded perfect when it ran there was no knocks rattles or any suspicious sounds

03-06-12, 08:43 PM	#14
rictus01 Member Mega Poster Join Date: Jul 2003 Location: South London Posts: 9,799	Re: curvy engine problem yeah you'll have the strip the heads off anyway, but try turning it over you've nothing to loose. the bigend bearing is the other end of the conrod from the piston (the conrod has a smallend bearing holding the piston on, and a big end bearing attaching it to the crankshaft). with the heads and the barrels removed, you should be able to give the piston a wiggle and feel for freeplay, if there is any, it shows the bigend is fubar'd __________________ Life should not be a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, in a cloud of smoke, thoroughly used up, totally worn out, and loudly proclaiming, 'Wow! What a Ride!

03-06-12, 08:44 PM	#15
rictus01 Member Mega Poster Join Date: Jul 2003 Location: South London Posts: 9,799	Re: curvy engine problem just a thought, is the rotor on straight ? __________________ Life should not be a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, in a cloud of smoke, thoroughly used up, totally worn out, and loudly proclaiming, 'Wow! What a Ride!

03-06-12, 08:45 PM	#16
curvysvboy Guest Posts: n/a	Re: curvy engine problem Sorry what do you mean rotor? And again im not sure! and will have a check

03-06-12, 08:47 PM	#17
rictus01 Member Mega Poster Join Date: Jul 2003 Location: South London Posts: 9,799	Re: curvy engine problem the alternator side (sitting on the bike LH side), has a rotor on the end of the crank, if this was to come off it could lock the crank, not a usual issue, but worth a look. __________________ Life should not be a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, in a cloud of smoke, thoroughly used up, totally worn out, and loudly proclaiming, 'Wow! What a Ride!

03-06-12, 08:52 PM	#18
curvysvboy Guest Posts: n/a	Re: curvy engine problem Right I will check that first then start stripping the heads etc. Would you reccomend taking the engine out completely and doing it on a bench? Any key points or parts to pay special attention to?

03-06-12, 08:55 PM	#19
yorkie_chris Noisy Git Mega Poster Join Date: Apr 2007 Location: Halifax/Leeds Posts: 26,645	Re: curvy engine problem You should be able to to find out what is wrong with it in frame. As normal there is slight angular play in the conrod and slight side clearance too. However if you can feel any radial play like up and down movement in the rod then the big end's knackered. __________________ Currently Ex Biker Now rebuilding a 63' fishing trawler as a dive boat

03-06-12, 08:59 PM	#20
curvysvboy Guest Posts: n/a	Re: curvy engine problem Right ok, what if ive stripped the heads etc off and big end bearing seems fine but engine still locks, what would your next venture be?

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