SRX timing chain

[chippit]

Hi,
I have an srx600 that is not running quite right, it has only done 9000 miles. I have stripped down the carbs and replaced all the 'O' rings and fuel tap diaphram, It still seems to be missing slightly when backing off from 60-70. There is also a slight rattle from the engine, timing chain? or tappets. I will check the timing this afternoon. Just wondered if the timing chains cause problems, does the adjuster stick.
I know that someone will know the answer,again thankyou to all you knowledgeable folk out there.
Regards Christine.

[Steve H]

Ive not heard of timing chains wearing, and the adjuster seems fairly robust. Pistons can slap around a bit but I wouldnt have expected this on a 9000 mile engine.
Is the bike standard ?, its not a small leak in the exhaust making a noise is it ?

[themoudie]

Hi,
I have an srx600 that is not running quite right, it has only done 9000 miles. I have stripped down the carbs and replaced all the 'O' rings and fuel tap diaphram, It still seems to be missing slightly when backing off from 60-70. There is also a slight rattle from the engine, timing chain? or tappets. I will check the timing this afternoon. Just wondered if the timing chains cause problems, does the adjuster stick.
I know that someone will know the answer,again thankyou to all you knowledgeable folk out there.
Regards Christine.

Aye Christine,
First, have you emptied the fuel tank entirely and filled with fresh fuel? Could be water in the fuel if the bike has lain about alot.
 
Secondly, "Replaced all carb 'O' rings and fuel tap diaphram.". Have you accidently altered the float height of the carb, when replacing the 'O' rings?

I hope this might help.

My regards, Bill.

[chippit]

I have adjusted one of the tappets on an exhaust valve, found that there was slight corrosion on
HT lead, plug cap end tried to start it and it is back firing. I left all the carb settings as they were,
float height was at 28mm I will get it running tomorrow and check timing and pilot screw setting.
The only thing that I have changed is that I replaced the blocked air filter with a K and N.

[themoudie]

Aye Christine,

Touch weak maybe, by the sound of it, or an airleak on the intake side between the carbs and inlet stubs. With the bike running, spray WD40 on the rubbers and see if you get any changes in engine note or drying out areas where the WD40 is getting sucked in.

Either of the Steves may have other ideas or explain better than I, as might Andy230 if he drops by. Busy man these days!

My regards, Bill.

[Steve Lake]

hi...what gaps are you using for the tappets?
I've found on mine that backfiring on the overrun is usually a result of a leak in the exhaust system...do you have a standard system?...are the header pipes making a good gas seal into the head...might be worth putting in some new copper rings

good luck

Steve

[chippit]

What should the tappets be set at? It is starting and running well (no missing on over run now)
but difficult to start once warm and is back firing when I am trying to start it. The exhaust is standard and in good condition with no leaks. I have checked that the carb inlets to head are sealed (replaced the 'o' rings when I put the carbs back on.) The spark plug is a DPR8EA NGK set to 0.8mm, I have a new coil on the way so will try that, there was some corrosion in the HT lead at the spark plug end and the spark did seem a little weak. I have a spare SRX400 CDI unit that is not fitted with a side stand switch. Is it compatible with the 600? and how do you check the timing? I presume that there is no adjustment. It could be that I am not kicking it over fast enough!
Thanks Chippit.

[Steve H]

Tappet clerances can be found HERE
The import CDI can be fitted and will work, I seem to remember the cut-out for the ignition being fiddly and the colours slightly different, but is was a few years back.
You mentioned you have checked the carbs over, is the choke shutting off correctly ?

[chippit]

Yes the choke is shutting off, I will double check tappet clearances when I get chance.
Thanks

[Steve Lake]

one thing worth checking is the automatic exhaust valve lifter, which operates off the kickstart, make sure there is the correct amount of free play, and that it is releasing fully, grease up both ends (I usually pack some grease into the little housing under the kickstart spindle, it stops road crud getting in and seizing things up)

[chippit]

Running right a last!
I dropped the float height to 27.5, didn't think that it would make so much difference.
The bike starts when hot now which it was (or I was) struggling with. No miss fire on over run.
The rattle I could hear was one of the exhaust tappets and not the timing chain.
Is that lovely blue colour on the headers nearest the engine a sign that its running at the right temp.
Thanks for the advice,
Christine.

[Steve Lake]

as long as its not too blue....it could be running a bit weak....whats the plug look like after a good run?