Problem KLR
 

Okay all you "Sabelotodos" out there. All replies,(even patronising), received with gratitude,,,

Kouritsimou, my poor, abused burrito did not take too kindly to being locked in a Colombian shed for 3 months with no prep. work whatsoever. I returned full of beans with an equally full bag of spare parts. First she wouldn't turn over, so I bought a new battery. Then, the only way I could get her to fire up, was by blocking the air entry to allow a richer mix, but she would die again and then revive when I persisted and got her really hot,(Ai, las chicas!!). At first I was sure it was a carb. problem, but after thorough cleaning nothing had changed. I brought in some local boys who are great at basic stuff, but they have no diagnostics here, and it's all guess work. Everyone then thought it was the carb, later the electrics and now we've settled on lack of compression. Basically, we can phaff about enough to get her going, warm her up, but on letting out the clutch, there's no, (read sometimes), power. On stripping the pot down, there does seem to be quite a bit of wear, (sunlight through the piston rings), Is this enough to cause such a massive change in response, given that she's done nothing for 3 months?

Ta v.much

Hi there Stretcher M,
First, I have to say that I don't know about KLRs, never owned one etc.
But, I have to agree that not much can have changed over 3 months, so, if it was my bike, I would start with all of the simple things - loose connections for instance. anything chewed away by little furry things?, and that type of thing - has anyone been able to fiddle with it while it has been stored?

This link might give you help and ideas:

http://www.horizonsunlimited.com/hub...al-stuff-27640

I found it recently when I was doing loads of work on my bike,

Good luck,

Dave

ps You don't say much about the history of the bike - mileage, model/year, that type of thing - folk who do know about the KLR will ask this!

Can you double check your float valve in the carb?
 

Hi Stretcher Monkey!

I had a similar problem with my KLR after it was stored for a couple of weeks.
The bike had no power. I had to rev it a lot to keep it running and as soon as I would try to ride in first gear it, the engine would die.

At first I thought that I had clean my carb correctly. I could not see any dirt in there. But I was missing one small thing: The float valve was stuck!!!

I would suggest you to double check if your float valve work properly!

Hope this help,
Patrick

Patrick beat me to it, I had an duke 750ss that had been standing for a while and turned out to be a sticking float.

Could be worth a check?.


Roy:thumbup1:

Sticky float valve
 

Ah, the float valve - mine sticks when the carb has been drained by running it dry with the tap shut off and the engine running - something that I used to do regularly, but no longer. Therefore it was sticking in the open position so fuel pours out of the overflow.

Gentle tapping on the side of the float bowl gets it to work OK and I do this with the rubber handle of a hammer - this gives a bit of "weight" to the tapping without damaging the casting of the carb.

Dave

Same thing happened to me. Stuck float valve.
Brian

Thanks Peeps!
 

Thankyou for your input, with not one patronising comment in sight. Where are you Mollydog!

This poor bike; 3 years,(80,000 klicks), on the road between Argentina and Guatemala, and then back to Colombia, bits around and inbetween. She´s been on boats on the Amazon, sailboats on the Caribbean, 100's of kilometres of deep sand, IN the sea,(never been jet-washed), crossed many rivers and been horizontal in the same. She's been crashed twice, (not by me, I hasten to add). She's 3 years old but looks 30

I have had problems with the float valve myself, in the past, and naturally that was my first impression. Unfortunately from what you lot say it's also now my last impression. I can't believe that anything has changed that much in 3 months - No furry things, no meddling hands. Problem is, the old girl is in about 200 bits. I will get the piston and pot checked out anyway, as we have got this far. We have had this carb. in bits countless times, so I doubt a hammer will work at this point, anyway. I am returning to Blighty for a couple of months soon, so I may as well take said carb. with me. Anyone able to recommend any fine British carburretor engineers?

Thanks again for you positive input. You may have saved me some time and money.

[quote= On stripping the pot down, there does seem to be quite a bit of wear, (sunlight through the piston rings), Is this enough to cause such a massive change in response, [/quote]

"pot" means cylinder?
piston rings are measured at the gap...I don't know the specific KLR specs, but "ballpark" you should have about .010"
the rings will be shaped so the explosion forces the rings against the cylinder walls, and they have to float.

...what can happen when sitting is the rings stick in the carbon-cruddy grooves of the piston and don't expand against the cylinder walls.

do a quick compression check...you want to see 125psi+...100psi will run, but not impressive....if compression is low, it can be crud under a valve seat, stuck rings, or blown head gasket because young Pedro had your bike at the hill-climbs in your absence...

it sounds like it's getting spark but not gas...another thing to look for is dry rot in the intake boot causing a vacuum leak or something silly.

I would look for a mud dobber nest blocking a vent/drain tube, or float valve stuck.if you have spark and compression, I would suspect insects or mice doing what they do best...and your bike is just another opportunity.

The fuel petcock on the KLR won't let fuel flow from the tank unless there is a vacuum signal from the engine. If the valve (I think it is actually a rubber diaphram) is stuck or broken, it could be your problem. Could also be a plugged hose from the intake on the engine to the petcock. Or the hose could have fallen off at the petcock, mine has. Easy stuff to check.

Thanks again fellas
 

On inspecting the rings, there is about 0.25 gap at the widest point which is excessive but not that bad. Not cruddy at all. She was running fine on the day I left her, and no signs at that time. Fuel is pumping fine to carb. Now I am convinced that the float valve is the problem, but will use the opportunity to put her back together better than before. She deserves that. I'll let you know what happens.

Chao

Hi again,
Not sure if you have a manual for your bike model/year but it sounds like you know the bike well if you have taken it to bits so completely. I hope it does turn out to be something simple but 80000 km sounds like a potential case for some more major work - rebore or whatever, hence you need the manual for the tolerance values. As other posts, this sort of thing does not go wrong overnight, usually - got to be something simple therefore!!!:rolleyes2:

The link that I included in my earlier post has lots of info about servicing carbs - if you have cleaned them already then you know them as well as anybody else I would say. It's also got information about what to expect for compression values.

If you are heading back to the UK then your local Yellow pages may be the best way of finding professional help,

Cheers,

Dave

It wasn´t me who dismantled the bike so completely, but my moto monkeys. Methinks they are better at dismantling than reassembling, but we shall see. In the UK I would never think of hovering over my mechanic as they worked, but in Latin America it is essential that you supervise and question every single step.

Standing 3 months - what's changed?
 

Back to basics: As Mollydog asks, what has changed since the bike was last running?
The more you can talk it through on here/with your moto monkeys the more chance of identifying what the problem is.

When you bring that carb back to the UK, maybe you can bring the whole engine, excess baggage permitting??!

Let us know how you are getting on with putting it all back together; IMHO, not much can have changed in your 3 months gap - lots of people leave bikes standing for that time with no prep and a bit of TLC brings them back to life. I realise that you have devoted some TLC already but it just has to be something "basic".

Cheers,

Dave

In reply to some of the posts above:

To check the compession of a KLR you will have to disengage the automatic decompresor or your pessure gauge will always show you too little compression to run healthily.
This is done by taking out the exhaust cam and blocking the mechanism with some thin binding wire. Make sure that you understand how the decompressor works and that your wire contraption does not interfere with anything when turning.
BTW: The decompressor is failsafe and is not a possible cause of the problem.

Patrick: The doohickey sits on the balancer chain idler shaft and has absolutely nothing to do with the timing chain. I have never heard of timing chain tensioners on KLR's giving trouble and I don't think that after 80000km the timing chain is stretched enough to exceed the range of the tensioner and jump.
If the balancer chain jumps by a couple of teeth due to a broken doo and idler spring the fwd balancer will make contact with the crankshaft web. Bang! I am not sure if (read: don't think that) the balancer chain can jump without doing externally visible damage to the alternator covers.

In reply to the original question:
Did you check your valve clearances? Very tight valves can cost you compression and cause starting problems and cause the valve and seat to burn (primarily exhaust burns, intake often survives a while without serious damage.

I would start to look for the problem in the carburettor. Check for dirt in the slow jet as well as in the main jet mixing tube's crossbores and especially in the idle mix adjustment screw (that's the one under the f...ing anti tamper plug) Your description of not starting unless choked and engine not producing any power points straight at a carb problem.

A stuck ring and compression loss are possible but the bike should have used oil and smoked before as this does not happen on a healthy engine.
General piston and ring wear is also possible although it does not explain the sudden problem but then you should also have noticed high oil consumption before engine expiry. The engine should also have smoked considerably (blue) during your starting attempts.

A rebore and a new piston and rings is not too bad an idea after 80000 KLR kilometres. Even if not necessary yet it would have been soon. Get the valves and seats remachined and replace the valve stem seals.
Replace the water pump shaft seals while at work if not done recently.
Get an Eagle lever to replace the doohickey if you don't have one already.

Good luck with getting the bike fixed!

The above balancer meets crank must obviously read REAR balancer shaft. The fwd balancers orbit nicely out of harm's way r and l of the crank with a naked shaft in between.