CDI retard and advance honda xr200

[norman1015]

Like the old Harley,s had a throttle on the right,and distribute advance,and retard on the left.Honda xr200 has trigger coil mounted to a round plate.  I think it would be easy to install shoulder bolts. ? That would allow the trigger coil to move while engine is running.Then find away to move trigger coil.Cable,screw threaded some way,or the way model T  throttle worked.I'll bet teamrude has already done it.Anyone think of this:norman1015

[teamrude]

To be truthful I have not done that. I physically mark flywheel with degree marks after I verify TDC. I also have played with advance springs and advance limiters. On my very high compression strokers I modify advance so I have 2 degrees more initial and a couple less at rpm's. So basically a higher intital setting and lower total. By adjusting spring tension I usually have full advance around 4-4200. This got rid of detonation at 3-4000 range when hot and under load.

 

On side note, ALWAYS verify total advance at rpm's. Found advancers can be off big time. Just because you set it to "F" mark at idle does not mean total is correct. Total and where it comes in at is more important than idle setting!!!!

[chadzu]

How do you check total advance with a timing light without getting bathed in oil?

[teamrude]

Chad, you could always wear your ladies finest sunday dress...... Seriously it is a mess but may save your motor. I lean it slightly sideways and have friend start and wind it up. If you do this right it is pretty quick but still messy.

[norman1015]

I thought so points,and trigger coil are kinda the same,but a trigger coil is hard to accurately tell where the direct spot is the triggers ignition.Where ignition points break it fires.

[Chuck.]

The Honda Shop manual says use a timing light, those who have tried that know the experience.   

I also checked the position of the marks on the advancer vs the sensor with a timing light and they matched at all rpms that I checked, that says the ignition system fires when the advancer/sensor marks align. 

 

So I now do a static check:

When checking ignition timing always turn the crank forward towards the marks (CCW e.g. engine running direction) to replicate engine running condition.  Also adjust the cam chain tension before checking the timing.

 

To check ignition timing; pull the spark plug, CDI cover, and the two plugs on the left side cover. Carefully turn the engine forward (CCW) with a socket on the flywheel bolt via the lower hole on the left side cover until the "F" mark on the flywheel aligns to the mark on the case (top of the upper access hole).  Adjust the sensor plate so that the line on the Advancer aligns with the line on the Sensor.  This will set the initial timing. While you're there you can check total advance by moving the flywheel CW back past the double marks, and then rotate CCW to the double marks; the left mark (first) is 32 degrees and the right mark is 28 degrees.  Twist the advancer CCW and check the alignment between the advancer and the sensor, if they align the  advancer is in spec at 20 degrees.  For a new engine I think you should limit total advance to 28 degrees, which is the right mark.  This will slightly reduce initial timing with a very slight loss of bottom end but you can go back to factory timing after break in, which is total advance between the two marks (30 degrees). 

 

I have had similar experience with advancer units as Terry, and total is very important and should be checked.  I also have ping in the 3000-3500 range on my 218 and need to slow down the advancer a bit. The advancers have vinyl or rubber sleeves on the posts as stops for full advance, your advancer should have these and don't attempt to remove them, they are easily broken.  If you want to further restrict advance you could add a piece of shrink tubing to each post.  To slow down the advance so total is at a higher rpm you need; lighter weights (I have no idea on source),  higher rate springs, or shorter springs that provide more preload.  Be careful of ebay advancer as the one that have springs with a gap between two coils are from an XL which have a faster advance than the XRs.   The space makes the spring free length longer so they have less preload when installed.

 

With the above you can check the mechanical advance (should be 20 degrees),  and the total advance.

[KENC195]

1981 XR 200R

 

What is the advancer? 1981 XR200R

 

I just made a post about the 81 being a beast to start. I just bought a performance coil and will be putting that on tonight.

 

http://s1288.photobucket.com/user/kenc195/media/xrdone2_zpsac694b14.jpg.html?o=1

[Chuck.]

On the left side of the cylinder head is a shiny aluminum cover for the CDI sesnsor system, two parts; the sensor which sends an ignition fire signal to the CDI black box, and the Advancer unit that is attached to the cam and has a magnet to trigger the sensor along with a mechanical advance unit to control ignition timing. 

 

When these bikes are tuned properly and with the rings/valves in reasonably good condition the engine often feels like a half kick starter when warm.  Mine have usually been two/three kicks when cold, depending on how long they have been in storage,  and almost always one kick when hot. So a couple of issues; engine in reasonably good physical condition, properly tuned, and proper starting technique.

Tuning includes; a good spark plug, good ignition system properly timed, clean carb properly jetted/adjusted, and valves and timing chain properly adjusted.

[KENC195]

Okay it's been a year and I didn't realize I left this post hanging. I did change the ignition and played around with the timing and things are a lot better. After sitting for a month, full choke 2 slow kicks just to move some air in and then 1 reasonale kick and it starts right up and idles smooth.  after 30 seconds, choke all the way off

 

The problem today is low end seems to be strong at about 1/3 throttle the power starts to fall off and has some sputtering. Sometimes staying on the throttle "clears it out" but not always. Carb is clean, new plug, now coil

 

Any ideas?

[Chuck.]

When everything is correct these motor always seem to run well; so the question becomes what happened?

I try to eliminate possibles by:

Using a Irridium spark plug: NGK DR8EIX. It will provide spark  under marginal conditions such as when starting.

Do frequent valve clearance checks and retension timing chain.

Keep carb clean by using an inline filter and draining the carb before even short term storage.

Ethanol blended gas has created a maintenance nightmare for carbs so that is the first thing to check.

[KTM520EXC]

Drain float bowl, remove plug to bottom of carburetor, remove main jet and if the emulsion tube comes out with it, no big deal. 

 

Remove main jet from emulsion tube (if still attached) and make sure you can see sunlight, or artificial light threw main jet.  

 

If you think you can see an obstruction, either use a very fine copper wire in the main, or dip in carburetor chem dip. 

 

From what you are describing, sounds like the main jet. 

 

Michael 

[Go Big Red]

Old thread but someone chime in.  This system seems an awful lot like an old GM HEI system with springs to bring in or slow down total timing and rotating the cap to advance or retard initial timing. Is that correct? Just want to be sure before I start messing with it. And if that’s the case, does this motor respond better to a little more initial timing for low end power or is it a different theory for the little thumper?

[KTM520EXC]

Yes, Yes & Yes. You can advance the initial with the advance/retard plate and there is a mechanical advance vs. advance being controlled by the CDI. 

I ride in elevation (3,500 to 5500 ft), so you lose compression the further in elevation you go up, so I can get away with it more than others. 

My butt dyno says 2 to 3% increase in power across the whole power band, noticeable, but not mind blowing. If you are riding at sea level, I would

try advancing just a skosh and go in small increments. If you go to start it and it bucks, or kicks back, that's too much. You would want to retard it

at that point. 

Michael 

 

 

 

 

 

[Chuck.]

Couple of more points to consider:
Compression does make a difference in combustion burn speed.
Stock 10:1 compression ratio was designed for pump regular.
The hemi combustion chamber is more prone to detonation than other types so be careful with spark lead.

I had an original untouched  stock 90 engine with enough hours on it for 2nd gear to be noisy and compression pressure was down to 165psi (190 is spec). Engine ran great with 34 total advance and pump premium.
I have an earlier engine with 10.5:1 Powroll big bore piston and I limit it to 30 total with pump premium and have no problems.
My XR218 with 11:1 CR is set at 29 total for pump premium and it has ping events when hot while exiting corners (usually on tight ST in 3rd gear).
The two parallel marks on the flywheel are at 28 and 32 degrees, in between is the safe place for total timing on a stock engine. The "F" mark is at 10 degrees BTDC.