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-   -   Testing pick up coils? (https://www.horizonsunlimited.com/hubb/yamaha-tech/testing-pick-up-coils-42090)

Tenere Tom 11 Apr 2009 16:13

Testing pick up coils?
 
I am having a few issues with my old XT.

It won't go over 60mph - that's with or without a passenger.
It is like there is nothing left but I know there is. It starts and runs OK so it's not the engine itself.

Is there a way to test the pick up coils (in the left hand side of the engine).

I don't know if they work in stages like 0-3000 revs and 3000-6000 revs.
If this is the case I suspect the higher rev coils are faulty.

Tenere Tom 12 Apr 2009 15:39

Thanks for all the advice guys:thumbdown:

I've swapped the coils over and the bike is running the same so I'm going to start looking at the carb now to see if there are any blockages or dirt in there.

I might even look at upping the jets a little as I have a Sebring end can and the mix can be changed a little.

Has anyone re-jetted their XT? I'm not sure what standard sizes are (can't find them in my Clymer manual) so I'm working blind.

aukeboss 12 Apr 2009 22:42

jet size
 
If you go to: Wartungsdaten XT600-Modelle

there are data for XT's. Look for 'hauptduse' which is main jet. Nothing for '84 models though.

Depending on what exactly happened when the problem developed (whne you installed the new exhasut or before or after?) I would not go immediately to larger jets - first check that the second carb (right side) opens when required, then raise the needles one notch at the time etc.

Auke

zigzag 12 Apr 2009 23:00

hi tom clymer manual page 271 for there sizes but i have a yamaha service folder that differs these are the yamaha sizes . for a 43f like mine main jet in both carbs is 130 ,pilot jet in primary carb is 46 . for a 34l tenere main is 125 in both carbs pilot in primary is 48 . if all was well before piston problem ,and now all is not well check cam timing and compression ,dos it just stop at 60 mph or miss fire , it sounded fine to me so i dont think its too bad a problem if i can help in any way get in touch zigzag:thumbup1:

Tenere Tom 13 Apr 2009 10:54

Cheers zigzag - I'm used to all the data being at the beginning of a section (like in a Haynes) not at the end!!!

thetallyhoman 16 Apr 2009 02:03

tom tenere team talk tech
 
hey tom,
sound like your primary and secondary carbs had a fight and the secondary lost and is a little sore, did you try to see if secondarys cylinder will open with a vacum tube???
if it still slides, then it still might not want to open at higher speed, (air leak on diaphram) (primary used a knife... little rat)
the other suggestion if everything checks out good is to put a little engine oil or 2 stroke in with the petrol, about an eggcup and a half, it works for slightly sticking sliding cylinders. it really can make a huge difference.

subie 20 May 2009 14:28

Hello Tenere Tom
You describing my Xt Tenere 34L exactly .
After 4500 rpm there is just not much happening. I went through the carbs endlessly,finally fabricated a small fuel tank,took the boots off and ran her like that to physically see with a torch what the sec carb is doing. Everything works fine there in both carb throats. Sec carb opening nicely with a healthy petrol mist sucked up by the venturi action.
Finally I have measured the ohm values of the magneto and pick up coils. they were way off their values. I can see sombody has done some shitty rewiring job in there with one of the lobes with no windings on it. This was all a couple of months ago so I have forgotten the values that they should be and what they was. I havent been able to find somebody in South africa that can rewire them for me.
I am sure there must be somebody just haven't found them yet as I am living in a small town in the bundu. I feel confident that this has got something to do with my lack of power (timing not being electronically advanced as there is no high rpm power or corect voltage. Hope my CDi is not damaged by all this.
Have you found the problem with your bike yet?
My bike starts and run okay,uses very little oil and very reliable but slow like a tractor lots of torque but no go :-) I am riding my other bike as finances are too low to spend on the XT now.

subie (south africa.)



Quote:

Originally Posted by Tenere Tom (Post 237292)
I am having a few issues with my old XT.

It won't go over 60mph - that's with or without a passenger.
It is like there is nothing left but I know there is. It starts and runs OK so it's not the engine itself.

Is there a way to test the pick up coils (in the left hand side of the engine).

I don't know if they work in stages like 0-3000 revs and 3000-6000 revs.
If this is the case I suspect the higher rev coils are faulty.



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