Why Won't You Start!!!

[tkent02]

It has started recently (pretty easily), so while I fully intend to do a valve adjustment very soon, I don't want to wait till I have just to find I have the same issue still...

Far better to just wait until the valves burn up, then fix all of it at once. That way you get to pull the head and everything.

[Larry D]

I know! I need to do the valves... I've been procrastinating, I'm terrified I'll break something.

Anyhow, story of the bike.
After I got it from the OP, Changed the air-filter and did an oil-change and I cleaned the carbs... badly.
Didnt work, so I started learning on here.
Cleaned the carbs better, still no soak (couldnt find).
Now it worked but rather badly (high and not very reliable idle).
Bought some carb cleaner and soaked the carbs and changed the o-rings, also polished the exhaust. Now it wont even think of starting.

Ahhhhh...no worries. You won't break anything. Heck, valves get adjusted all the time without anything breaking. Seems you've done everything else EXCEPT adjust the valves..........so......maybe.....just maybe......that's what it is. Give it a shot, you're not losing anything, it has to be done to be reliable and you're not riding now. May as well do it right.

[Adler]

Alright alright... lets get this ball rolling...
Is it a good assumption that these are not precise enough?

http://www.canadiantire.ca/AST/browse/4/Auto/AutoTools/GeneralAutomotiveTools/PRD~0256178P/9-piece%252BValve%252BTappet%252BGauge%252BSet.jsp?l ocale=en

These look better but they arent automotive specific...

http://www.canadiantire.ca/AST/browse/6/Tools/SpecialtyTools/MechanicsSpecialtyTools/PRD~0581246P/3-in.%252BLeaf%252BFeeler%252BGauge.jsp?locale=en

Strongly considering these, but that means i have to wait 3 weeks for delivery....

http://cgi.ebay.com/New-1-Set-Precision-Feeler-Gauge-0-002-0-025-840392-/300464947020?pt=LH_DefaultDomain_0&hash=item45f51b3f4c

[hampshirehog]

Any decent car accessory / tool store should carry feeler gauges and they shouldn't cost much (a few $s). Make sure you get a metric set - the maths is just so much easier.....

Ideally you should get a set that goes down to 0.03mm though the cheaper sets usually only go down to 0.04mm. The latter will be fine - you could end up running with slightly large clearances but this is fine (around 0.1mm is about as high as you should aim and will be achievable - in theory with the cheaper gauges 0.09mm is as wide as you need go). The book of words says 0.03mm to 0.08mm.

[Adler]

Any decent car accessory / tool store should carry feeler gauges and they shouldn't cost much (a few $s). .

Shockingly Canadian Tire doesnt have a decent set...
Im going to buy these, theyre on sale and look wonderful!

http://www.princessauto.com/hand-tools/autmotive-tools/auto-repair/2990117-deluxe-feeler-gauge

[Octain]

Ya know this valve adjustment thing really has me baffled. My 850 valves were wayyyy tight and not only did it start really easy but it also ran very good. As a matter of fact all of em were too tight for the feelers. Granted they were loose enough to rotate the bucket but every single one of em were out of spec.
Not to argue, the valves need adjusted but how dang tight do they need to be for the bike not to start?

The 850 is now within spec and other than a little more noise I cant tell a dang difference.

Seems as long as you can rotate the bucket then the valve arent stuck open, the bike should run.

[tom203]

I'm arriving late to this , but I need an Adler summary.
1/ first carb cleaning- no good but bike still ran?
2/second carb cleaning- not better but bike still ran?
3/ bought carb cleaner, soak carbs, changed o-rings, but now it won't start?
I'm sure it needs a valve adjustment, but why doesn't it start? Are your plug wires on correctly? doublecheck,cuz this is easy to do in haste.

[Adler]

I'm arriving late to this , but I need an Adler summary.
1/ first carb cleaning- no good but bike still ran?
2/second carb cleaning- not better but bike still ran?
3/ bought carb cleaner, soak carbs, changed o-rings, but now it won't start?
I'm sure it needs a valve adjustment, but why doesn't it start? Are your plug wires on correctly? doublecheck,cuz this is easy to do in haste.

almost... after the first carb cleaning it didnt run... after the second it did run but not too well. I had carb cleaner the whole time but I bought a jug big enough to dip things in for the third cleaning

I thought about the plug wires being wrong but then it wouldnt run on starter fluid would it?

[bellucci]

No tank... everything exposed... pull all the plug wires, pull the plugs and make sure they are damp. Now put fresh plugs, recheck the plug wires carefully. Choke the snot out of it and don't touch that throttle... After that doesn't work, check the dang valves. When you are done with the valves, let us know how it runs... We are rooting for you...
Curt

[tom203]

I thought about the plug wires being wrong but then it wouldnt run on starter fluid would it?

That's a point to ponder- since the plugs fire twice in the four stroke cycle, I wonder whether the ether could still go bang with miswired plugs.I guess I'll have some more coffee now.

[Adler]

Alrighty guys,
I finally checked my valves and here is what I found;

[CODE]
Cylinder Shim In Shim Ex Clearance In Clearance Ex
1 2.70 2.67 <0.0015 0.0025
2 2.70 2.70 0.0025 0.0025
3 2.70 2.75 <0.0015 <0.0015
4 2.65 2.70 <0.0015 0.0015
[/CODE]I realize that I mixed metric and imperial measurements here.
The point is ALL the buckets turned freely so I would think that these measurements are not far enough off of spec to cause my no-start condition (I'd be delighted to be wrong). Of course, I'll still change the shims to make them all perfect but in the meantime I'd like to figure out why its not starting!

[BassCliff]

Hi,

The spec in inches is .001-.003. It seems half of your valves are too tight and one more is at minimum. (I find it easier to measure in millimeters, .03-.08).

Do you have the airbox installed?

Since it catches with starter fluid but then dies, it seems like a fuel issue. If the airbox is not installed then you could be running too lean.


Thank you for your indulgence,

BassCliff

[Adler]

Hi,

The spec in inches is .001-.003. It seems half of your valves are too tight and one more is at minimum. (I find it easier to measure in millimeters, .03-.08).

Do you have the airbox installed?

Since it catches with starter fluid but then die, it seems like a fuel issue. If the airbox is not installed then you could be running too lean.


Thank you for your indulgence,

BassCliff

The airbox is indeed installed. I agree that it sounds like a fuel issue but wouldnt it have to be VERY lean for it to not even sputter? And if the carbs are at fault, can't it run on 2 or even 1 cylinder? meaning ALL the carbs would have to magically have stopped working after i put in fresh o-rings!

Puzzling indeed... When I have more time later this week I may switch the carbs for a spare set I have to see if that will do it.

[Steve]

It still amazes me how many times advise will be ignored/rejected because "it can't possibly be that because ..."

Tight valves are notorious for causing hard starting on cold engines. Part of the reason is that the valve will be held open later due to the tight clearance. This allows some of the mixture that is in the cylinder to be pushed out the intake valve, back through the carb. The carb does not care which way air is moving, it sees moving air, more fuel is added. Moments later, the piston is going back down, the valve is open, air goes back through the carb AGAIN, picking up even more fuel. To add insult to injury, the "choke" is probably set, making the mixture far to rich to even think of burning.

This only happens when the engine is cold because of metal expansion. The head expands as it warms up and clearance from the cams to the valves will increase a bit. Hard to say just how much, but it must be enough to help the valve timing and starting problems.

How tight do they have to be to cause this hard starting? I have not been able to measure that point, as it is smaller than the thinnest feeler in any set I have ever owned. The last time I had a bike with those hard-starting symptoms, I don't remember if the buckets could be rotated or not.

Bottom line: adjust the valves. Keep them well-adjusted. Record your results (see the bottom of my sig).
In the first four hours after you asked the first question, valve adjustment was discussed more than any other topic.
In fact, it was mentioned just four minutes after the question.

However, nobody mentioned one other tip: THROW THE STARTING FLUID AWAY.

If the bike won't start, fix the problem, don't thow "band-aids" at it.

.

[Adler]

Thanks Steve, I hope you're right and its just the valves, I just assumed that if the valves werent too far off I would at least be getting SOME action out of the engine. I knew from the start the valves were a suspect but I also knew they would take me the longest to fix and I definitely didnt want to find it wasn't the valves causing the issues (though I'd do them anyways, I know how these bikes are finicky like that).

As to the starting fluid, I would never use it to start the bike! It is just a diagnostic tool, if it burns with the starter fluid then I doubt the problem is electrical in nature.