SV650.org - SV650 & Gladius 650 Forum



SV Talk, Tuning & Tweaking Discussion and chat on all topics and technical stuff related to the SV650 and SV1000
Need Help: Try Searching before posting

Reply
 
Thread Tools
Old 25-05-19, 07:03 PM   #1
gst
Junior Member
 
Join Date: Feb 2019
Posts: 4
Default K3 cam tensioners in curvy - power loss and exhaust afterfire

Bought a 2000 curvy about 6 months ago with the usual cct rattle. After going through many relevant threads I have replaced the originals with K3 model. Procedure followed -
1. Removed spark plugs
2. With rear piston at compression stroke TDC, removed old cct and dropped in the k3 one. Timing mark at R. Wound engine anti cw, no strange noises.
3. Followed same procedure for front piston with timing mark at compression stroke TDC.

Engine is running, no rattle, but there is noticable power loss and afterfire at deceleration. After a couple of days, it died during idle a couple of times and sometimes needs to be cranked twice to start.

Any opinions/advise would be greatly appreciated. Read in a thread that both ccts should be removed and replaced at F timing mark, but cant seem to find it again. Is it true? Is the timing wrong know? Remedy?
gst is offline   Reply With Quote
Old 25-05-19, 08:23 PM   #2
maviczap
Member
Mega Poster
 
maviczap's Avatar
 
Join Date: Mar 2007
Posts: 9,096
Default Re: K3 cam tensioners in curvy - power loss and exhaust afterfire

Can't see how changing the cct's is going to cause your issue, unless the chain has jumped and the timing is out, but as there are no rattles. Think if you'd got it wrong, then there would have been a big bang.
However you could check the compression on both cylinders to see if there is a loss, which might mean the timing was out and the valves had touched the piston and bent them, but if expect the engine to be noisy.

Perhaps when removing the plugs you've disturbed the plug lead and it's not sparking properly, our you've not seated the plug cap properly or not got the plug in tight?

Have you disturbed the airbox when lifting the tank to get to the rear plug?

Have you trapped the fuel line or not attached the vacuum line to the tap properly?
__________________
We're riding out tonight to case the promised land
Make everyday count
RIP Reeder - Jolly Green Giant and comedy genius
maviczap is offline   Reply With Quote
Old 25-05-19, 08:30 PM   #3
johnnyrod
Member
Mega Poster
 
johnnyrod's Avatar
 
Join Date: Jul 2003
Location: Doncaster, oop norf
Posts: 2,122
Default Re: K3 cam tensioners in curvy - power loss and exhaust afterfire

Did you turn the engine with the CCTs removed? It does sound like the timing is a bit off, or the camchain is very tight. The K3 ones go straight in, no messing around. You could try relieving the tension and letting them re-set. Normally this means taking them out but with (for example) the K5 ones you can poke a screwdriver down the tunnel and press on the ratchet pawl to let it off (this is after removing the CCT spring). When I fitted mine years ago I admit I just slapped them in, turned it forwards by hand a few times, and fired it up. They work well.
johnnyrod is offline   Reply With Quote
Old 26-05-19, 07:42 AM   #4
gst
Junior Member
 
Join Date: Feb 2019
Posts: 4
Default Re: K3 cam tensioners in curvy - power loss and exhaust afterfire

Thank you very much for your prompt replies. The airbox was removed and refitted and made sure all hoses tightened. Fuel line I have to check. The spark plugs I believe correctly tightened but I will check again. Any ideas about the timing marks? Should they be at F and R respectively or both at F one revolution apart? Indeed I suspect the rear being overtightened if I installed it at the wrong mark. I didn't turn the engine with the ccts out. I appreciate all your help
gst is offline   Reply With Quote
Old 26-05-19, 10:14 AM   #5
SV650rules
Member
Mega Poster
 
Join Date: Nov 2016
Location: Shropshire UK
Posts: 1,357
Default Re: K3 cam tensioners in curvy - power loss and exhaust afterfire

Unless you actually removed the cam chain during the fitting of CCT I don't see how timing would be affected. Was the bike running OK when you got it apart from the noise from tensioners ? If any valves have been bent I expect more than just a little loss of power.
__________________
2016 SV650 AL7

Courage is resistance to fear, mastery of fear, not absence of fear - Mark Twain
SV650rules is offline   Reply With Quote
Old 26-05-19, 10:50 AM   #6
gst
Junior Member
 
Join Date: Feb 2019
Posts: 4
Default Re: K3 cam tensioners in curvy - power loss and exhaust afterfire

Hi, yes the bike was running ok apart from the rattle.
gst is offline   Reply With Quote
Old 26-05-19, 12:31 PM   #7
squirrel_hunter
Member
Mega Poster
 
squirrel_hunter's Avatar
 
Join Date: Apr 2005
Location: Sunny Swindon
Posts: 3,570
Default Re: K3 cam tensioners in curvy - power loss and exhaust afterfire

Your timing is out as you've used the wrong timing marks when removing the rear CCT.

The F and the R is for a clearance check not for removal (I've made this mistake as well).

Check in the manual (either Haynes or workshop) but the short version is front cylinder first, rotate to TDC and the F mark on the timing. Remove and replace the CCT. Now rotate 360 and the rear CCT can be removed and replaced.

For valve clearance check it is the same but after the front rotate 270 to the R mark and check.

I would suggest you check your timing. Take the valve covers off starting with the front and make sure that is aligned, I suspect this will be fine. Now to the rear where I would guess you're off. Ensure that the engine is at TDC. Take the CCT out align the cams and the chain. Replace the CCT. Rotate the engine twice and check alignment.

And now while you are in there do a valve clearance check.
__________________
"A little enthusiastic?"

May I add here, GG is awesome and I think I am in love with Stretchie...he rocks my world!

SH2 | 2MA | GROM | YSR
squirrel_hunter is offline   Reply With Quote
Old 26-05-19, 06:37 PM   #8
gst
Junior Member
 
Join Date: Feb 2019
Posts: 4
Default Re: K3 cam tensioners in curvy - power loss and exhaust afterfire

Thank you for confirming my fears! Will follow your suggestions hoping I didn't do any damage.
gst is offline   Reply With Quote
Old 26-05-19, 07:00 PM   #9
Othen
Guest
 
Posts: n/a
Default Re: K3 cam tensioners in curvy - power loss and exhaust afterfire

Quote:
Originally Posted by squirrel_hunter View Post
Your timing is out as you've used the wrong timing marks when removing the rear CCT.

The F and the R is for a clearance check not for removal (I've made this mistake as well).

Check in the manual (either Haynes or workshop) but the short version is front cylinder first, rotate to TDC and the F mark on the timing. Remove and replace the CCT. Now rotate 360 and the rear CCT can be removed and replaced.

For valve clearance check it is the same but after the front rotate 270 to the R mark and check.

I would suggest you check your timing. Take the valve covers off starting with the front and make sure that is aligned, I suspect this will be fine. Now to the rear where I would guess you're off. Ensure that the engine is at TDC. Take the CCT out align the cams and the chain. Replace the CCT. Rotate the engine twice and check alignment.

And now while you are in there do a valve clearance check.


What excellent advice. It is exactly what makes this a really good forum.


Sent from my iPad using Tapatalk
  Reply With Quote
Old 27-05-19, 05:14 PM   #10
maviczap
Member
Mega Poster
 
maviczap's Avatar
 
Join Date: Mar 2007
Posts: 9,096
Default Re: K3 cam tensioners in curvy - power loss and exhaust afterfire

Shows you how much I know!
__________________
We're riding out tonight to case the promised land
Make everyday count
RIP Reeder - Jolly Green Giant and comedy genius
maviczap is offline   Reply With Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Loss of power - Curvy. juliensc SV Talk, Tuning & Tweaking 5 05-10-13 12:12 PM
One-off loss of power - K5. Braindead101 SV Talk, Tuning & Tweaking 2 28-08-13 03:18 PM
Loss of power, now no go at all. jnr-biker SV Talk, Tuning & Tweaking 8 22-11-09 10:50 PM
Power loss!! chris8886 Bikes - Talk & Issues 12 01-12-07 12:56 PM
Loss of power..... Nekkid SV Talk, Tuning & Tweaking 16 21-10-04 05:00 PM


All times are GMT. The time now is 02:02 PM.


Powered by vBulletin® - Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.