Hard Starting--Plugs?

[superdave]

Not sure if this is a plug problem, or a carb problem.

The bike is getting pretty hard to start. Usually if I go out and hold the choke all the way on, it will start briefly but die very quickly. I cannot rev it up either; if I do so it will try to die more quickly.

I can get it to start on ether generally. But I can tell that it isn't running on all 4 cylinders at first. The other day I got it running and was on the highway and noticed that I didn't have the power I normally do. I pulled the clutch and revved it up real high (near redline) a couple times and then it was like the last cylinder came "on line". Then I had all the power I should.

I figured that for whatever reason the one cylinder wasn't working when I started up but it started firing when the rest warmed up a bit.

I pulled the four plugs a few hours after a failed start attempt (didn't have time to mess with ether and such) and found that three looked pretty good, dry, light brown etc while number 1 was wet and smelled gassy.

I was thinking that maybe the problem was that it was getting cooler and bought a set of the "hotter" plugs mentioned in the manual. I stuck one in #1 and the bike seemed to start better, though it might have just been because it wasn't fouled yet. I pulled the spark plug wire while it was running to verify that spark was getting there. (I was zapped when it was off the plug and the engine bogged as that plug stopped firing.) So that means electricity is getting to it.

What I'm wondering is if it would hurt to run the hotter plug now since the temps are cooling. (I live in Kansas.) I do some highway riding and the manual did mention that generally in higher speed riding the cooler plugs would be preferable to avoid engine overheating. But maybe this is counterbalanced by the cooler weather. (highs in the mid 70s now.

Is there anything else to look for? Why would this one plug be fouling?

 

[tkent02]

Have you adjusted the intake and exhaust valve clearances properly?

 

[bwringer]

Have you adjusted the intake and exhaust valve clearances properly?

Have you adjusted the intake and exhaust valve clearances properly?

 

[Steve]

Have you adjusted the intake and exhaust valve clearances properly?

Have you adjusted the intake and exhaust valve clearances properly?

Have you adjusted the intake and exhaust valve clearances properly?


You notice a theme here?

In the meantime, GET RID OF THE ETHER and go back to the stock plugs.
Even in colder weather, you do not need hotter plugs.

.

 

[SVSooke]

Ask this guy if valve adjustments important http://www.thegsresources.com/_forum/showthread.php?t=166797 next to last post.

 

[Steve]

... next to last post.

"next to last post" only assumes that nobody has added anything to the thread.

More correctly, it's post #12.

.

 

[SVSooke]

Yes you are correct.Nobody had added something yet.Point still stands though.

 

[DanTheMan]

Me too!!!! Adjust your valves.
Read this!

"Okay, just wanted to share some really encouraging bits about the result of a simple valve adjustment.

I'd read on the board here that my very-hard-to-start problem with my 1981 GS1100Ex could be caused by poor valve adjustment.

The symptoms I had when trying to start the bike were:
- I had to open the throttle all the way, then crank and crank it
- meanwhile pulling the choke then releasing it, on-and-off, and keep cranking it with the starter (also supposedly not good for the starter to keep cranking it like this).
- finally after a few false startups, I could keep the motor running.

So I read on here that the 'hard to start' might be a valve adjustment problem, so I set out to check for that.
But I had no experience that valves being out of adjustment could hurt the ability of the motor to start, so I took it
on faith. I pulled the valve cover, then measured every tappet clearance. They were very bad.

Every tappet was WAY out of spec (a couple had .03mm, most of them I could not even slip my smallest (.03mm) feeler gauge in to get a reading)

After finding that every tappet/valve clearance was out of spec like that, and adjusting them, that is literally all I did to this bike, when I went to start it the first time -- I pushed the start button and it started instantly and didn't need the choke, just the throttle a bit.
MAJOR improvement. In fact, a hugely dramatic change.
One of the main reasons the seller sold the bike to me was his complaint "I can't get it started."


I'm glad I have this 'Before/After' of what the effects of very badly out-of-spec valve clearances can do. Just totally nixes the easy-starting of the motor.

Just wanted to share this with other folks out there who might be kind of new to dealing with 'hard-starting' symptoms.

And thanks to you folks for helping me out along the way in this thread. "

 

[spyug]

In addition to the valve adjustment , I might recommend the coil relay mod. With the old wiring harness you likely have corroded connectors which are not allowing for full voltage to the coils. Doing this mod and cleaning up and or replacing all connectors will rejuvenate the electricals and make starting easy.

Valve adjustment first, however.

Good luck and let us know how it goes.

Cheers,
Spyug

 

[superdave]

Hmm, I detect a pattern here...

I was planning/hoping to do some of these type things a little later on when it is too cold to ride, as I didn't want to have the bike down while waiting for new shims to arrive, etc.

Looking at pics, it seems that the Suzuki shim adjustment procedure and even shims may be very similar to my old VW Diesel motor.

 

[Big T]

Dave,

Have you adjusted the valves yet? J/K

You should take the hour or so it takes to check the clearances, determine what you need and ride it until you get your shims.

Try the Shim Swap Club for the new ones

Get the spreadsheet from Steve, it's a real handy tool for keeping track of where's you're at and what you need, valve clearance wise.

However, if the valve clearances are the issue and you symptoms are as bad as you state, you might want to hold off on riding and minimize the risk of burning some valves

 

[Steve]

Looking at pics, it seems that the Suzuki shim adjustment procedure and even shims may be very similar to my old VW Diesel motor.

Yes, probably very close, but the shims are likely NOT interchangeable. Suzuki uses 29.5 mm diameter shims. Be careful when you look for shims, Kawasaki uses 29.0 mm shims. They look about right, but are loose in the buckets. Order new shims from Z1 at $5.28 each to build your own collection or contact the shim club on this site for details on how they do 'business'.

Dave,
Get the spreadsheet from Steve, ...

Yep, that would be me.

Read the end of my sig for details.

.

 

[DanTheMan]

Contact Ghostgs1 for the shim club. He's da' man!

 

[superdave]

The idea of measuring then riding seems pretty reasonable to me.

The symptoms I'm experiencing sound similar to the posted thread and copied info. Certainly knowing my valves are correct can't hurt anything.

However, I'm wondering if the problem of the spark plug fouling up but then eventually having the bike run well (with the plug presumably eventually firing) is really part of this, or something else? Maybe the exhaust valve isn't opening far enough so the plug fouls up, then as things warm up and expand a bit the valve gets pushed open further and it runs better? I dunno.

Any thoughts on whether the (presumably) ill-adjusted valves can cause the plug to foul but then appear to start working after the engine has been running for a bit?

 

[salty_monk]

Once you've adjusted your valves & checked voltage at the coils (if low do the coil relay mod) you might want to think about cleaning the carbs properly & installing a new set of plugs.

Also try running the bike at night in the dark & looking carefully to make sure you are not losing any spark through a split in the plug wires or around the boots etc.

New spark plug boots might not be a bad idea either.

 

[Nessism]

The idea of measuring then riding seems pretty reasonable to me.

The symptoms I'm experiencing sound similar to the posted thread and copied info. Certainly knowing my valves are correct can't hurt anything.

However, I'm wondering if the problem of the spark plug fouling up but then eventually having the bike run well (with the plug presumably eventually firing) is really part of this, or something else? Maybe the exhaust valve isn't opening far enough so the plug fouls up, then as things warm up and expand a bit the valve gets pushed open further and it runs better? I dunno.

Any thoughts on whether the (presumably) ill-adjusted valves can cause the plug to foul but then appear to start working after the engine has been running for a bit?

The GS family of bikes is roughly 30 years old and by virtue of the age alone, these vehicles need maintenance. Lots of people come to the GSR and post threads about some malfunction or another without performing any routine maintenance first. Honestly, it's a waste of time to discuss possible specific causes for many of these ill running bikes until all the maintenance is up to date. Adjust the valves. Clean the carbs properly, change all the carb and intake O-rings. Make sure the air cleaner is serviced and the air box sealed. On and on it goes. Performing basic maintenance is how you build a solid foundation toward a reliable bike, and never a waste of time.

 

[tkent02]

The idea of measuring then riding seems pretty reasonable to me.

Unless they are way too tight. Running them way too tight can burn the valves.
If you are into the hard starting, they are probably way too tight. Hopefully no valves are burnt yet.
Have you done a compression check? Tight valves will also cause a very low compression reading.

 

[superdave]

The GS family of bikes is roughly 30 years old and by virtue of the age alone, these vehicles need maintenance. Lots of people come to the GSR and post threads about some malfunction or another without performing any routine maintenance first. Honestly, it's a waste of time to discuss possible specific causes for many of these ill running bikes until all the maintenance is up to date. Adjust the valves. Clean the carbs properly, change all the carb and intake O-rings. Make sure the air cleaner is serviced and the air box sealed. On and on it goes. Performing basic maintenance is how you build a solid foundation toward a reliable bike, and never a waste of time.

I have cleaned the carbs, changed out the bad intake boots, and installed new intake o-rings. I also located an airbox and got rid of the crappy pods that were on the bike as well as putting in new, gapped plugs. Also the tires were both replaced with new. So I got that going for me. But I had been putting off the valve adjustment as I said before. Hopefully getting that done will help me out.

 

[salty_monk]

Make sure your jetting is "as stock" too... that could be a cause of running rich if the previous owner messed with it to try to compensate for his crappy pods

 

[superdave]

When I was cleaning the carbs I looked at the numbers on the jets. While I don't recall what they were, I do recall determining they were the stock ones after doing some googling.

Also the nice light brown color on plugs 2-4 indicates to me that the jetting is probably correct.