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KTM Thumper Discussion

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Tourmeister said:
:tab So I busted out my 530 EXC for a ride today. It was a spur of the moment thing, so the battery had not been charged the day before and was dead. I was a bit worried because the bike has been sitting since before Thanksgiving and that usually means pulling the carb to install a clean idle jet. It took me a while, but I got it started and just let it idle a bit. Once warm, it didn't bog or die when I rolled on the gas, so I headed out for a great ride. The bike ran great. The rear tire is TOAST and I was sliding all over the place because it wouldn't hook up coming out of corners or in the sand/gravel.

:tab While cruising home on some pavement, I was running on part throttle at a constant speed (60-65pmh) and the engine was surging a little. At higher speeds and more throttle, it was perfect. Most of my dirt riding was either closed throttle or hard on it, with not much in between, so I didn't notice it. I parked the bike for a few hours at a meeting, then rode it home. That was maybe a 10 mile ride at most, but I was following Beth's minvan because it was dark and my headlight is laughable on a good day. Anyway, most of the way I was cruising in that range where the engine was kind of pulsing slightly. When I pulled into the garage, I noticed a slight smell. I got off the bike and when I looked at the right side, the header was glowing a nice cherry red!! :eek2:

:tab Here is my question. I am assuming the idle jet might normally be flowing at full capacity in this cruising range while the main jet is only partially flowing. However, if the idle jet were still slightly clogged, might that have been leaning out the bike in the range where I was having issues and thus caused it to run way hot? I have never seen it get hot like this. I am REALLY hoping I did not damage a valve or anything...

Thoughts?
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First to the important things. You didn't hurt your bike. The headers on four stroke dirt bikes glow in certain conditions on perfectly jetted and also FI bikes. In most cases, it is not a function of air/fuel mixture, but instead a product of pipe design and no airflow across the pipe (sitting in the garage idling or just shut down after a ride, especially in dark or low light conditions where you actually notice it).

You have a tough engine in your 530, especially the valve train. The only way you will hurt it is extended overheating where it will be obvious, such as all the coolant boiled out. You did not mention that it overheated--boiled coolant. As to your concern on the valves specifically, what hurts them is running them out of adjustment to the extreme (like zero clearance).

It is possible that you have a partially clogged pilot jet, but if the bike is idling normally then it is probably fine. Anything past 1/4 throttle and it is out of play anyway.

The last thing to consider is ambient temperature. Colder temperatures lean out the mixture and can require richer settings. A slight surge at steady throttle would be indicative of this.
 
Johnf3 said:
The last thing to consider is ambient temperature. Colder temperatures lean out the mixture and can require richer settings. A slight surge at steady throttle would be indicative of this.
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:tab Well all that other stuff you said is a relief!

:tab As for the temps, during the day it was mostly in the 60s and low 70s. In the evening when I rode home it might have been in the upper 50s. I do usually re-jet it for winter versus summer. Of course I can't remember what I have in it right now... :doh: I think the only difference is one clip position on the needle.

:tab I was surprised to see the glowing as I have never seen it before under any conditions, but I also don't usually ride this bike after dark. This time, I rode it home at about 60mph, so it would not have been an issue of lack of air flow. I pulled straight into the garage and shut it down. There was no running while sitting. The pipes are wrapped with fiberglass wrap to keep it from burning my pants. I saw the glowing through some of the holes in the wrap (another story...) and I could smell it. It was the smell that first got my attention.

:tab Man this makes me want a 500 EXC even more... :-P
 
The wrap is doing its job then. Glad you mentioned that. That stuff really holds in the heat. Better to get a pipe guard in my opinion, but anyway. I feel confident nothing was harmed. I have that same engine family as your 530 in my 2010 Husaberg and it is the toughest and most trouble-free dirt bike engine I have ever had. I have 300 hours of nothing but 1-3rd gear trails on it, and the valves have NEVER moved. I wrote down the clearances on all four valves when I first got it and they are exactly the same today seven years later. Stock piston and rings still too.

The fuel injection dirt bikes are cool, I have two myself, but they are not immune to fuel issues either. Old nasty gas can become a way bigger pain when an injector fails or plugs up. I have seen it. You will wish you just had to change out a pilot jet. You also have to deal with (I am speaking of KTMs as that is all I have direct knowledge of) a tiny little in line filter and also a bigger filter that is in the gas tank. Still better than a carb overall but not as simple to fix.

I remember last time we were talking about your 530 you were going to try some fuel stabilizer. Did you do that? With fuel stabilizer, sitting a few months should cause zero issues.
 
Johnf3 said:
I remember last time we were talking about your 530 you were going to try some fuel stabilizer. Did you do that? With fuel stabilizer, sitting a few months should cause zero issues.
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:tab The problem is that I don't remember to put it in every time I fill up before parking the bike. And, it needs to be run for a while to get the fuel with the stabilizer from the tank to the carb. So the end result is that it is not added consistently, which is totally my fault.

:tab I have had luck with the SeaFoam by adding it to a rough running bike and it eventually (over one tank or less) starts running much better. I often did that with the KLR and it would save me from having to pull the jets and replace or clean them. But you have to at least get it running in order to do that so it can run through the system. I might do that for the KTM if I can get the time to ride it again while the weather is SO FREAKING AMAZING! :lol2:

:tab All three of my GSs have been fuel injected, as were both of my VFR 800s. While I know they can have issues, I have never personally had any serious recurring issues with any of them, even when a few sat for several months without even being started. I suspect that so long as a blockage is not a hard substance like a small piece of grit/dirt, the pressure in the system combined with the detergent in most fuels nowadays can push through a slight clog and eventually clean it out. To be fair though, I did have to replace an inside the tank filter on one of the VFRs and it was a PAIN to do... That was the result of some bad gas with dirt in it and not from sitting. It probably would have affected a bike with carbs as well.
 
Scott,
The pilot jet has no effect off idle.
The crab components effect:
pilot jet - idle
slide cutaway - off idle
needle jet - idle to 1/8 throttle
needle - to 1/4 to 3/4 throttle
main jet - full throttle

My percentages might be off a little. I looked for an old chart I have, but could not find it. So, used memory.
When jetting go from main jet up.

I put fuel stabilizer in the tank after each ride. When I had a kick starter, I turned it out, so I knew stabilizer has added. Now, on the 690, I lift the fuel cap up.

Side note:
I've started using Star Tron. With an ozone added to a full tank, the low fuel light range went from 140 mi. to over 150 mi. Plus it cleans the injectors.
http://www.starbrite.com/item/star-tron-fuel-system-injector-cleaner?category_id=503
 
mcrider said:
Scott,
The pilot jet has no effect off idle.
The crab components effect:
pilot jet - idle
slide cutaway - off idle
needle jet - idle to 1/8 throttle
needle - to 1/4 to 3/4 throttle
main jet - full throttle

My percentages might be off a little. I looked for an old chart I have, but could not find it. So, used memory.
When jetting go from main jet up.
Click to expand...

I thought that as you opened up the throttle, the previous controlling jet was simply maxed out but still contributed to the overall flow of fuel? So while the pilot jet technically has no effect past idle once it is maxed out, it is still contributing fuel. So if it were to get clogged, it causes a partial reduction in flow. Is this not right?
 
Tourmeister said:
I thought that as you opened up the throttle, the previous controlling jet was simply maxed out but still contributed to the overall flow of fuel? So while the pilot jet technically has no effect past idle once it is maxed out, it is still contributing fuel. So if it were to get clogged, it causes a partial reduction in flow. Is this not right?
Click to expand...
That is very right, each jet continues to supply fuel as the throttle is opened.

I'd suggest raising your needle, a wee tad. Surging is a lean symptom as is high EGT, which would make your headers glow more than normal.

Sent from my SM-G900T using Tapatalk
 
:tab I'll probably verify my needle clip position and then start with replacing the idle jet that is in there with a new one. I have never had much luck trying to get one adequately cleaned once they have been clogged. I've tried wires, crab cleaner spray, and ultrasonic baths and none seem to work like just putting in a new jet :shrug: Of course, now I have to try to remember where I put the extra jets :doh: If the new jet doesn't fix it, then I'll start moving the needle clip.
 
I'd say that's a good plan of action. I stuck a Lectron in my 300 and love it... make life so much easier.

Sent from my SM-G900T using Tapatalk
 
Matt the Hatt said:
I'd say that's a good plan of action. I stuck a Lectron in my 300 and love it... make life so much easier.
Click to expand...

Funny you should mention that... :lol2:

After a particularly frustrating go round with the carb, I somehow stumbled onto something that mentioned the Lectron's and started looking into them. I got distracted and never did anything more, but it was certainly appealing. In all other aspects, I really like the 530 the way I have it set up. It is a blast to ride.

Did you install the Lectron yourself? If so, was it easy to get it sorted?
 
Tourmeister said:
Funny you should mention that... [emoji38]2:

After a particularly frustrating go round with the carb, I somehow stumbled onto something that mentioned the Lectron's and started looking into them. I got distracted and never did anything more, but it was certainly appealing. In all other aspects, I really like the 530 the way I have it set up. It is a blast to ride.

Did you install the Lectron yourself? If so, was it easy to get it sorted?
Click to expand...
Yeah it was easy. I got mine used but it was on a 300... if you get a new one they will set it up with the needle/metering rod pretty close.

It's still an adjustable carb, it just is very consistent over a very wide range of air densities so you don't have a need to adjust except in the most extremes of altitude and temperature. Throttle is crisp and responsive over the range of Texas temps. I'll be taking it to Co later in the year so I'm eager to see how it does there. Air density is air density whether it is from altitude, temp or humidity so I expect it to be pretty squared away.

I haven't needed to adjust mine set it up in the summer and it is still a one (or two) kick start in cold weather. There is a whole thread on them on advrider.com that is worth reading.

I was very sceptical of the mpg Improvements most report, but I went from 23ish mpg to a smidgen over 30mpg, on my 300xc. Those are street numbers, which is not shabby for a big old two stroke. Not sure you'll see that on a 4t, but who knows.





Sent from my SM-G900T using Tapatalk
 
Getting to know my 500 EXC today during a ride in the hill country. It's the first long ride (200+ miles) I've done on this bike.

P2110004_5_6_7_8-XL.jpg
 
greenhornet said:
Rich, what windscreen is that? I wonder if if would fit my 525...
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It is the MRA Roadshield Universal windshield, mounted with the MRA universal mounting kit for 28/32 mm handlebars (for 1 1/8 "fat" handlebars). It is a universal windscreen, so it will fit your 525. I bought it from Revzilla for about $125 total for the windscreen and mounting kit.


Sent from my iPad using Tapatalk
 
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Trail Boss said:
It is the MRA Roadshield Universal windshield, mounted with the MRA universal mounting kit for 28/32 mm handlebars (for 1 1/8 "fat" handlebars). It is a universal windscreen, so it will fit your 525. I bought from Revzilla for about $125 total for the windscreen and mounting kit.


Sent from my iPad using Tapatalk
Click to expand...

Cool, thanks!
 
:tab There are days where I think, "Is it all worth it...!?" :doh:

:tab I went out to the garage this afternoon intending to do a "quick" verification of my carb settings and to swap out the pilot jet with a new one. This requires removal of the tank because I have the 6.6 gallon tank. No biggie. Then I loosened the clamp on the carb boots and got it rotated so I could access the bottom. I opened it up and pulled the pilot jet. Holding it up to the light, I could see that it was definitely still clogged compared to the new one. So I popped in the new one. Just for grins, I thought I would double check the main jet. Sure enough, it is a 175. I went to screw it back in and just before it would normally start to snug, it went totally free... :eek2:

:tab At first I thought I might have stripped out the threads, but I wasn't even torquing it. I had two fingers on the KTM tool to make sure I wasn't twisting too hard. When I tried to back it out, all I got was the main body of the jet. The threaded portion was still in the carb!! :doh: Some days...:argh: I dug through all my other jets hoping I would have another 175... no luck. It's 5:00pm... Cycle Shack North in Conroe closes at 6:00pm. I am about 45 minutes away if the traffic isn't bad. A quick call confirms that they actually have them in stock, so I tell them I am headed that way!

:tab I get there with some time to spare and get the jets. Rachel sits on some small KTM two stroke, disc brakes front and rear, sweet... I of course had to check on the new 2017 500 EXC-F :rider:

:tab NO... I didn't buy one :-P But it sure was temping. I was blessed with long legs even though I am not real tall, so the reach to the ground was fine. Both feet reach nicely even with my street boots on. Looking at the row of bikes all around I am astounded at how expensive new bikes are now. The price increases in just the last few years are huge! I don't see how this trend can continue :shrug: They did have a nice KTM 1290 and an 1190 on sale. They had a sweet looking Honda Africa Twin as well. Given the price of the AT relative to what you get, I can see why they are so popular!

:tab Anyway, we left the shop without spending too much money. I got two main jets just for good measure. I had to stop at four different places to find an extractor small enough. Home Depot had it. I probably should have just gone there first :doh: Once home, I went ahead and just pulled the carb completely off the bike to make it easier to work on it. The extractor worked perfect and the piece came right out. I went ahead and tore down the whole carb just to give it a good cleaning. There was a lot of varnish in it. Once clean, I reassembled it and stuck it back in the bike. It was too late to fire it up as it would annoy the neighbors. While I had the seat off I put a fused charge chord on the battery, which I have been meaning to do forever. This way I won't have to remove the seat to put it on the trickle charger. It is all back together now.

:tab The next thing is to get the suspension tweaked. Rsquared helped me rebuild it a while back, but I think somehow the settings were off. I counted the clicks for all the settings, front and rear, then put everything in the middle. It has been really harsh. The plan is to go find a nice bumpy road and play with it until I get it right. I need to mount a new rear tire as well. The current one is toast.

:tab If the weather continues to be so incredible, I may have to do another of my DS rides out toward Crockett and Nacogdoches.
 
Hey Richard,

What have you done to the bike so far in terms of getting it setup for adventure riding?

I see you got a bigger tank. How much does it hold? Is the swap a pain?

You staying with the stock seat or going with something else?

Stock gearing?

Bar risers?

Steering damper?

Better headlight?

All that in the works...?

I need you to hurry up and get all that done so you can move on to your next perfect DS bike so I can buy this one off you :nana:
 
Tourmeister said:
I need you to hurry up and get all that done so you can move on to your next perfect DS bike so I can buy this one off you :nana:
Click to expand...

Hey!!! Don't say that on a public forum! My wife might read this and realize the truth of what you just said. :-P At that point, the game will be over.:rider:
 
In all seriousness, here is how the bike looks as of yesterday:

P2110019_20_21_22_23-XL.jpg


It has a 5.3 gallon Acerbis tank, which was easy to change as long as you don't lose the rubber gasket that seals the fuel pump inside the tank. I dropped the gasket somewhere in my driveway when I pulled the stock tank off and could never locate it, which is really odd considering it is quite large. The 5.3 tank takes up about the same space as the stock tank + shrouds.

The stock seat is uncomfortable for anything more than 30 minutes of paved riding (non-standing riding). I upgraded to a Fisher seat this week - and it's much more comfortable than the stock seat. I rode the bike 210 miles of pavement in the hill country yesterday and the Fisher seat was pretty darn good.

P2110001-XL.jpg


P2110002-XL.jpg


The stock seat is about 4 inches wide. Seat Concepts makes a seat for the 500 that is about 7 inches wide. The Fisher is about 10 inches wide. Tricepilot rode with me yesterday. He has a Seat Concepts on his 500 and, after riding my bike, said the Fisher was noticeably more comfortable.

I added a MRA universal windscreen to get the wind blast off my chest. For such a small scree it does a fine job. I like the way it mounts to the handlebars much more than the way a Slipstream or a National Cycles windscreen mounts.

_MG_0004-L.jpg


I am running stock gearing, which worked just right at Big Bend during Christmas. It might be geared a bit too high in 1st for riding in the mountains, but I won't know until I actually go ride it in the mountains.

_1160037_38_39_40_41-XL.jpg


On Tricepilot's recommendation, I added a Scott's steering damper. The stock handlebar setup was too low for me and the nice thing about the steering damper is that I was able to raise the handlebars 2 inches along with adding the steering damper.

P2120051_2_3_4_5-XL.jpg



It needs a better headlight. I've been told I can get a squadron light from Baja Designs and install it in the stock shroud, which is what I plan to do.

I added a Globetrottin rear rack with giant loop attachment point. It is a thing of beauty and should easily meet my needs for multi-day rides.

P2120046_47_48_49_50-XL.jpg


I still need a skid plate,hand guards, and some Altrider luggage.
 
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Before and After.

It was in supermoto form when I bought it.
untitled-5-XL.jpg


In dual sport adventure mode now.
_MG_0002-XL.jpg
 
mcrider said:
Richard, do you have two sets of wheels?
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Yes.

I have the original dirt wheels and a set of supermoto wheels the previous owner put on the bike.

The supermoto wheels are for sale since I don't anticipate ever using them.
 
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