The XL600 thread

[God of Speed]

Originally Posted by gorilla2891

How did that jet work for you? I was going to ask about your airscrew setting but saw on one of your post s that your year aint got one. maybe find some carbs that do?

you mean i was complaining about having no airscrew? i do that alot.

jet is good, starts 1-2kicks cold and 1 hot now, theres a bit of a lag in midthrottle but thats cos i havent adjusted the midrange jet to allow for the different pilot. point is, its fkn awesome man thanks!

as for the carbs, its a bit of an excessive exercise to find the earlier carbsn aus (not worth getting ones from USA), not to mention how much they would cost. im pretty happy with how the bike is set up at the moment so it shouldnt worry me whether i have an air screw or not.

changing all the jets is only a 5 minute job anyway.

[God of Speed]

in a way its probably good that i dont have one because i know that if i did i would be adjustingit all the time, you dont really need that much room for adjustment, there are enough other ways to change the mix, Soichiro was probably trying to just make it simpler for us mere mortals by removing it.

still...... now i feel like mine is the model for idiots and the earlier ones are for the pros.

[HeadTrauma]

Originally Posted by God of Speed

still...... now i feel like mine is the model for idiots and the earlier ones are for the pros.

If you want something definitely not for the faint of heart, try putting two FCRs on there...

[MortimerSickle]

mdkm85, before you spend the bux on a new CDI, see whether someone is willing to plug yours into their bike.

When I thought I needed a CDI, Zombie did this for me, and his bike started right up. The good part is I saved the price of a new unit. The bad part is I still don't know what is wrong.

[MortimerSickle]

Originally Posted by God of Speed

if it ends up you have to replace the CDI, dont go back to stock, go for the aftermarket ones. i have more power, better efficiency, easier starting, better throttle response all from just plugging a new CDI in.

I don't remember whether this thread is where I brought this up before, but watch your revs with aftermarket CDIs. From what I have read they often have their rev limiters set much higher than OEM for the 600.

IE:

cleonard@Thumpertalk:

Be very careful of the CDI's that are sold as "performance CDI's." The stock XR600 CDI has a rev limiter at a low 8000 (7500?) RPM. This keeps the engine safe. The XR400 CDI can be used and it has a 9500 limit. The XR250 CDI has a limit over 10,000. All are plug compatible. Many so called performance CDI's are nothing more than a XR400 or XR250 CDI. The problem is that the XR600 engine does not like those high RPMs. At higher than stock RPMs the valves start to be slow in closing. Eventually the piston and valves meet with bad results.

There are several options for programmable ignitions such as the MSD MC-3. http://www.msdpowersports.com/mc-3.html

There are also several do it yourself ignitions that you can make.

[HeadTrauma]

Not only do these engine not like high rpm, it's a waste to twist them like that because the are well out of the power by the stock 7500 limiter. The 250/400 CDIs also have more aggressive timing curves which can be a problem with high compression pistons.

[Reposado1800]

Originally Posted by HeadTrauma

Not only do these engine not like high rpm, it's a waste to twist them like that because the are well out of the power by the stock 7500 limiter. The 250/400 CDIs also have more aggressive timing curves which can be a problem with high compression pistons.

+1
Its all about that midrange torque. I have a couple of bikes and by far my favorite motor is the XL600 when tooling around under 65 mph. Blasting down rough dirt roads the motor is in its zone and surpasses the suspension very quickly.

[God of Speed]

in regards to you guys worrying about the cdi's rev limiter......

I was feeling a rather adventurous and curious so i did a top speed test. This of course included the rpms bouncing off the new CDI limiter and to be honest it did not seem much higher than the stock limiter. Not only that but with the retarding timing the new CDI has the engine feel much smoother at high rpms. If however you are worried about revving after a false neutral well might be an idea to shim that gear lever a bit tighter. I dont usually rev much higher than 6k even when really hunting.

Im very cautious about this bike. If i thought something i was doing was not good for it i would stop it straight away and woul never ever suggest something to someone else unless i had tested it thoroughly. You all know how much i love this bike and as much as i hate the notion of a miracle fix.......so far..........this CDI has given the bike a new lease on life. It gives me a whole lot more confidence in the capability of my knowledge of the bike and my riding skills. I guess the same CDI technology was not available in 1983 as what is available now.

Im not being paid to say this. It truly is what i believe and even if the cdi blows up and i need a new one in 1 year...........well its still totally worth it. As far as mods go this single thing has made more difference than every other performance mod i havde done PUT TOGETHER.

[God of Speed]

but as it has been said. You dont need to go anywhere near the rev limiter anyway with these engines and the CDI makes so much difference in other areas that the redline really is not something to worry about. Infact with the extra power i find im using lower rpms in general. So even if i miss a gear i am still 3000rpm away from redline. (and a slight tug on the bars away from an envious wheelie in 3rd.).

But anyway you guys make your own choices. Its just good to have all the options on the table. Important thing is that the CDI makes the biggest difference for the cheapest price and the least amount of mucking around. It might blow up tomorrow anyway........then id look like a right fool. But im not too worried as i lost all dignity when i registered with ADVRIDER 2 years ago

[MortimerSickle]

Uhh... I was just giving a heads-up on the nature of some CDIs.

I have no reason to accuse anyone of anything, and I certainly am not preaching how to use your bike (especially considering the way I ride mine.)

I just wanted to pass along a little information.

[God of Speed]

Originally Posted by MortimerSickle

Uhh... I was just giving a heads-up on the nature of some CDIs.

I have no reason to accuse anyone of anything, and I certainly am not preaching how to use your bike (especially considering the way I ride mine.)

I just wanted to pass along a little information.

no worries brother. Remember this is what the thread is for......getting to the bottom of things is the whole point and if we didnt argue we wouldnt get anywhere. One thing for sure is without you guys my bike would be out in the outback with seized rings/melted bearings and me underneath it in skeleton form.

And the CDI mod suits me cos im too lazy and poor to get a cam set or stroke/bore kit.

[God of Speed]

your quote mentioned something about making your own ignitions? how would one go about that i wonder. maybe it is possible to reprogram the other CDIs to have a lower redline?

[MortimerSickle]

Originally Posted by God of Speed

your quote mentioned something about making your own ignitions? how would one go about that i wonder. maybe it is possible to reprogram the other CDIs to have a lower redline?

Dunno, you'd have to ask cleonard.

[HeadTrauma]

Originally Posted by God of Speed

1.) your quote mentioned something about making your own ignitions? how would one go about that i wonder.

2.)maybe it is possible to reprogram the other CDIs to have a lower redline?

1.) MegaJolt comes to mind. It started as an offshoot of the MegaSquirt EFI.

2.) AFAIK, stock CDIs are not the least bit easy to reprogram. They are sealed and potted in epoxy and have chips inside that were never available to anyone outside of Honda. Ford did the same thing with the earlier EEC-IV by having Intel build the 8061 processor. It took a lot of reverse-engineering before the aftermarket got it sorted out.

[gorilla2891]

Got my remote res mounted up where my crank case breather/separator was.[IMG][/IMG]
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