Will a XR600 CDI box work on an XR650L?

Yes, I think the best option is to run various advances on the dyno and see what it gives you for your own engine set up.

The XBR racer made more power with 8degs of advance and was also noticeably easier to start.

The high octane fuels tend to respond well to more advanced ign so theres just to many variabes to generalise.

This was for a road-racer and not an off-road bike of course - the demands of the two types of riding will be different.

Honda RFVC CDI boxes: (The GB500 uses the MK6 CDI)

CDI part # idle advance full advance

MG3-003 6 BTDC below 1200 31 BTDC at 4000

MK6-671 8 BTDC below 1200 21 BTDC at 4000

MG2-871 11 BTDC below 1200 31 BTDC at 4000

MG2-891 11 BTDC below 1200 31 BTDC at 4000

MG2-892 11 BTDC below 1200 31 BTDC at 4000

I read about guys using xl600 CDI's in their gb500 because the xl600 has 10 more degrees of advance.

Has anyone tried the MSD CDI for single cylinders. If it works on the XR650L You should be able to program any curve and rev-limit you want. Cost may be a little on the high side. I haven't been able to easily find prices on it.

http://www.msdpowersports.com/single_cylinder.html

Tobin

I'm using a Megasquirt.

Id be interested in either!

Anyone know the costs involved?

I'm using a Megasquirt.

has this box made a difference? any links?

Just caught this thread, lots of great info.

So the 650l runs off the battery and is ac?

What about the older xl's, IE xl 500 ro 350 early 80's? They run of the flywheel and just use the battery for lights. Would the xr600r's CDI work on them? I have been told it will, but now I am questioning that.

Just caught this thread, lots of great info.

So the 650l runs off the battery and is ac?

What about the older xl's, IE xl 500 ro 350 early 80's? They run of the flywheel and just use the battery for lights. Would the xr600r's CDI work on them? I have been told it will, but now I am questioning that.

the 600r is ac, as is the 650r. 650l is dc. the older ones are ac also I THINK!

As far as I know all the XR's and XL's are magneto ignition except for the 650L that runs off of 12 volts. The earlier 70's XL's use a mechanical advance. Depending on the exact model, they went to electronic advance around 1980.

82 was when the xl500 went CDI. Just needed to know if it was the same as the 600r. I am pretty sure it is. THanks for the info

Ive decided Im going to buy a MSD ingition for my XRL based racer.

Seems to be the best way of getting more revs and the best midrange and top end power gain.

Ive been quoted £150+17.5% tax here in the uk. so I assume theyre about $300. Could be cheap HP!

Lead time is 4 weeks to the UK so should have the bike back on the dyno early 08. Also have a NX650 CDI (which Im using) and new XR600 CDI I could try as a comparison at some stage.

Will post dyno results on motopike.com and here

I called summit racing. They sell the MSD 4217 for 366.39. I think that may be full retail but I'm not sure. Seems a little expensive. I wonder how much of an advantage a more aggressive timing curve will provide on a stock engine? I have read that raising the compression will often require more advance on the timing. Does anyone know what the timing curve for the XR600R is? It's compression ratio is 9.0:1. The XR650L is 8.3:1. The factory honda service manual for the xr650l gives these specs for the timing.

8 degrees @2300 RPM

28 degrees @ 4000 RPM

full advance

28 degrees @4000 RPM

I wonder if honda went with a more aggressive curve because they are using a higher compression ratio in the XR600R and whether it would be beneficial on an L with the stock compression ratio. I am curious at what RPM it starts to curve. I noticed in the chart earlier in this thread that most of the other boxes started at 1200 RPM. It could be possible that a stock L would benefit from more advance earlier on but wouldn't really benefit from as much total advance.

Tobin

if you search long enough a guy did a post where he graphed the curve. bout a year ago if i remember right.

I called summit racing. They sell the MSD 4217 for 366.39. I think that may be full retail but I'm not sure. Seems a little expensive. Tobin

hell no would i spend near that much for a cdi no way you can get enough gain for that price, prolly no more than $100 will be a good gain/price value.

Hi,

Sorry - I dont agree. Programmable ignitons can give 'cheap' horsepower on tuned engines both in terms of midrange and peak power. Shifting the 7500rpm soft limit will also give more top end power straight away.

I'll post the results before and after the ignition mods.

What you also have to remember is that a new Honda CDI retails at £100 here. the programmable one is £150 but infinitely better for setting up modified engines like mine.

To get an equivalent PVL system would be much more expensive.

?action=view&current=ignition.gif

The heart of that schematic is the PIC 16F84, a microcontroler. It needs to be programmed in order to function. Do you have the code for it? Without that code the circuit is useless.

While that circuit looks like it would work, I think I would make a few changes due to the characteristics of the XR components.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now