Timing one tooth off

kli · Feb 28, 2012

Hello dear,

just opened clutch cover, put engine in TDC, and see that my timing is one tooth off, at least I think so

I was checking by drawing from Owner doc's, can you please check am I write and do I need to adjust the timing, should I remove cam one tooth back?

thanks in advance

kli · Feb 28, 2012

Sorry my picture it's not uploaded, you can see it bellow.

thanks

DuaneB · Feb 28, 2012

Pull your clutch off... align the dots... slide your clutch back on... making sure the engine is at TDC when you align the dots.

zaga · Feb 29, 2012

Hi

Here is how iy should look.

[attachment=0:1trt1r9d]Timming.jpg[/attachment:1trt1r9d]

:cheers:
ZAGA

kli · Feb 29, 2012

That's what I soppose, so one tooth back.

Thanks

john_tonnesen · Apr 12, 2012

Do they run whit one tooth of?? Hard to start? Backfires?

Taffy · Apr 12, 2012

they can run but they are hard to start and backfire and cough etc. the valves usually miss the pistons on the bigger 650 engines but on the 400-501s the exhaust valves chase the pistons and leave a mark on the top. that is where the missfire comes from. you will need to check the valves for bending and also do a sealing test on the upturned face and some white spirit etc.

regards

Taffy

helithumper · Apr 12, 2012

I would also remove the valve cover and make sure that the cam is at TDC (two dots on the cam gear are flush with the top of the head).

P.S what happened to you engine case between the two gears. It looks really chewed up.

kli · Apr 12, 2012

Like Taffy say it was a bitch to start and was backfiring on deceleration.

I dont know what was with case, it's the damege made by preowner of bike I wind out for this when I open the bike, to me it looks like that timming chain was broken.

Since I adjust timing bike starts good and runs fine with some small backfiring, sometimes on 1st kick usualy 2nd or 3rd.

Taffy
Bike was running cca one hour with wrong timing.
You suggest take head off and check valves for bending?

What you mean by sealing test with upturned face and some white spirit etc.

Thanks

Taffy · Apr 13, 2012

helithumper said:
I would also remove the valve cover and make sure that the cam is at TDC (two dots on the cam gear are flush with the top of the head).

P.S what happened to you engine case between the two gears. It looks really chewed up.

did they have dots back then?

if your valves are leaking a fluid will go past the valves.

fit a spark plug, lay the head upside down, poor in white spirit and see if the fluid enters the ports. you'll need the fluid right up to the very, very top as it is the 'top' edge of the inlets that leaks.

regards

Taffy

kli · Apr 13, 2012

I wasn't removing upper part of cillinder head so I don't know if the dot's are on gear.
Will do that soon because, i'm waiting timing chain to be delivered, I need to change it too, so I will check that than.

Could be leak of valves be recognized by some other symptoms while the bike is running, without taking cilinder head down?

Taffy · Apr 13, 2012

you can use a compression testing tool. car dealers have them. you hold the tool in the plug hole and then turn the engine but because you have a single cylinder bike you have nothing to compare it too!

it is always worth looking at this plus to see if the inlets are tuliping.

you will need a new head gasket.

regards

Taffy

helithumper · Apr 13, 2012

you can use a leak down tester. It's like a compression tester but instead you are filling the cylinder with air. you will hear the air coming out of the exhaust or the intake if the valves are leaking. if you use a leak down tester make sure your valves are adjusted properly or you'll get bad readings. it will also tell you what the percentage of air that is leaking.

Bergini · Apr 13, 2012

just a side note, when i bought my bike the timing chain was off one tooth, when attempting to daingose the concern compression was good so i then used a cylinder leakage tester and it would not work, it would spin the engine as soon as pressure was applied to the cylinder, i have not tried it since i reset the timing to know if it will work.
with leakage tester and timing off mine would spin clockwise, i can only assume but if it was a tooth off the other way it would try to spin couterclockwise, and if piston is at tdc like the marks indicate it would allow pressure to build without spinning the engine. that whole last statment is an assumption, i have not tried a cylinder leakage test since the timing was set back true.

helithumper · Apr 13, 2012

Sorry I forgot to mention to lock the crankshaft with the locking tool or it will spin on you.

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