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Message started by manny87 on 02/10/14 at 12:30:01

Title: Timing or Carburetor?
Post by manny87 on 02/10/14 at 12:30:01

Per the guidelines here's the info on my bike and myself:

It's an '87 with 36K miles on it. I did the belt to chain drive conversion. Did the verslavy mod (i think that's what someone called it) to the timing chain tensioner at around 17K miles. didn't know it was a common mod and that it even had a name... at the time it was just a logical "temporary" fix i came up with but i guess it's a keeper... (unlike some other ill-advised temp fixes that I've come up with) ... that's it, as far as modifications go.
I know a thing or two about especially automotive mechanics although I don't do it for a living.

So recently i changed the timing chain and refurbished the rocker arm tappets. The problem was, i put it all back together, It starts without a problem, but when i go full throttle, it will rev all the way up nicely and then it sort of chokes and revs down for about half a second, then revs up for half a second, down, up, down, up ... the whole time, the throttle is wide open, also backfires randomly during the process. The up-down revving seems to have a steady frequency, half second up, half second down ish... but the backfiring happens randomly. i suspect either the carb caught some dirt or something while i was fixing the other stuff. Or i got the timing wrong. That brings me to something else... Is there any timing mark on the other side of the crankshaft? the right side, if you're sitting on the bike i mean.... Because i can't see the mark on the left side... i see the groove on the inside of the hole where you unscrew that big round cap but not the mark behind the crankshaft bolt, it literally looks like someone filed it off.... So i found TDC by rotating and feeling the piston in the up position... But i noticed the piston stays up for a little bit even if you continue to rotate a few degrees... or I thought it did.... plus, i was rotating the crankshaft clockwise to find TDC... i've read that you're supposed to do it counter clockwise so i'm mentioning that so someone might be very kind and explain why it makes a difference.

Another thing is that, even without letting it reach the point where it starts giving this problem, i.e. without going full throttle... it just feels slower, lazier... It could be that i'm using a Honda CX650 as a backup bike in the meantime (faster) so now my savage feels slow... but it doesn't feel quite right. and given the symptoms... could the timing be a bit off? should i start by cleaning the carb? I'd appreciate any help.

Title: Re: Timing or Carburetor?
Post by anebv8 on 02/10/14 at 12:48:48

this is a photo I used when I set my timing,managed to fluke it and got it set first go :)

Title: Re: Timing or Carburetor?
Post by manny87 on 02/10/14 at 13:01:51

Thanks, what about the bottom mark? is there one on that same side of the engine?

Title: Re: Timing or Carburetor?
Post by justin_o_guy2 on 02/10/14 at 17:02:37

The crank is set by pulling the plug in the left side case, theres a notch that lines up, kinda upper right, IIRC. Gotta turn it CCW to get it there & then make sure it didnt drift any before ya button things down,
SO,, Get it on TDC, lifters should be free, & check that thing on the left,,
Or, set the crank TDC & check lifters,, either way, they hafta agree..
Did ya do anything to the carb while it was down?

Title: Re: Timing or Carburetor?
Post by manny87 on 02/11/14 at 04:51:52

nothing to the carb at all... just removed it, put it in a box while i worked on the other stuff, then put it back in. I was only able to work on the bike for a couple hours on saturdays so the carb was down for about a week or two. Based on the symptoms (revving up and down on its own and backfiring while throttle wide open) i thought it must be either timing is a little off or the carb needs a cleaning.

The other thing is... i can't set the crank using the mark on the left side case. The notch is there when i remove the plug, but the mark on the crankshaft is gone, filed off or something. Are there other marks anywhere else to set the crank?

Thanks for your help.

Title: Re: Timing or Carburetor?
Post by SavageCat on 02/11/14 at 07:51:53

You seem fairly on top of things so sorry if this suggestion seems basic....but what petcock do you have? Its a pretty common issue on these bikes - just wondering if its a fuel delivery issue? Or as others mentioned, maybe the carb needs a good cleaning.

Test your Petcock - http://suzukisavage.com/cgi-bin/YaBB.pl?num=1251932429/1

Title: Re: Timing or Carburetor?
Post by Serowbot on 02/11/14 at 08:19:49

Why would anyone file off the timing mark?... :-/...

Check again,.. I think you're just missing it...

http://i235.photobucket.com/albums/ee201/Digger109/TDC-IndexMarksE.jpg

Title: Re: Timing or Carburetor?
Post by manny87 on 02/11/14 at 11:31:07

.but what petcock do you have? Its a pretty common issue on these bikes - just wondering if its a fuel delivery issue? Or as others mentioned, maybe the carb needs a good cleaning.

Test your Petcock - http://suzukisavage.com/cgi-bin/YaBB.pl?num=1251932429/1[/quote]

Thanks for the suggestion, I'll have a look at that too

Title: Re: Timing or Carburetor?
Post by manny87 on 02/11/14 at 11:43:57

3E283F223A2F22394D0 wrote:

Why would anyone file off the timing mark?... :-/...

Check again,.. I think you're just missing it...

why indeed? I know, right? but i understated it, sorry, it doesn't look filed off... it looks like someone took an angle grinder to it... I'm sure I'm not missing it, It's gone!!! I'll see if i can take a picture or something... anyway are there any other marks to set the crank? and what about the symptoms? (backfires, revs up and down... all during wide open throttle, plus it feels lazy). Actually, I'll try to take a video this weekend when i go back to where the bike is... And post a link or something so y'all can see/hear what i'm talking about, In the meantime, any other ideas?

Again, I appreciate your help everyone.

Title: Re: Timing or Carburetor?
Post by justin_o_guy2 on 02/11/14 at 12:12:51

If the mark is gone, the only other way I know is pull the plug & run a smooth wire in the hole, rotate the engine close to TDC, then probe the piston, slowly rotate the engine & hold onto that wire, stop when it stops coming up. If you go past by 3 or 4 degrees, meeehhh,, no bigggee,, the chain wont be a tooth off, Itll line up. YOull know its past tdc a hair, so if the chain "wants" the cam gear rotated Top of cam gear forward a few degrees, go with it, If you pass TDC w/ the piston a coupla degrees, then the line on the cam gear would be okay a little low on the front side, instead of perfectly level w/ the head.

Title: Re: Timing or Carburetor?
Post by manny87 on 02/11/14 at 12:21:24

736C6A6D70774676467E6C602B190 wrote:

Thank you, In that case I doubt it's the timing... or maybe i just hope it's not... I'll check the carb first and see how that goes...