NavyJetFixO

Member
Dec 18, 2004
4
0
I cannot get my 1997 Honda CR500 mx'r to start.
- Background: Low hours bike, no mods/rebuilds, all equip is original. Sits for months at a time. Ran fine last time ~ 6 months ago.
- Here's what I've done:
1. Fresh gas, new plug
2. Dissembled, inspected and cleaned the carb. No problems found, no varnish build up.
3. Verified spark by grounding on top of cylinder head. Spark is yellow/blue in color.
4. Verified ohm resistance on electrical components per Honda Service Manual. All ck'd OK.
5. Ck'd electrical connectors. All OK.
6. Ck'd reeds for any damage. All OK

Symptoms. Bike has good compression, and appears to be getting fuel from the smell of gas on the plug when I remove it. It will momentarily fire usually one time when I first start kicking it over. Then nothing each kick after. Seems to make no difference whether chock is on or off. I suspect the Ignition Control Module (ICM) may be faulty with respect to the ignition timing. But there is no way to verify this module other than to replace it ($200!).

Please help
Fly Navy!
 

magneto

Member
Nov 14, 2001
179
0
Is the plug getting wet and shorting out when you kick it over? I'm guessing your carburetor overflowed and allowed gas to puddle in the crankcase. You can flip the bike upside down and turn the motor over with the plug out to check/clean out if necessary.
 

bikepilot

Member
Nov 12, 2004
804
0
Make sure the reeds are in good shape (and sealing against the cage well). If they are not sealing well the CR5 can be very very hard to start. Its very rare for the ICM to go bad but I suppose its possible. I've had bikes not start, pulled the plug, verified spark etc, plug looked good, re-install still no start, replace plug and it starts right up. I have no idea why, but its not uncommon. I'd recomend trying a new plug before any other parts, even if it looks good and sparks to the head.



Here's the drill that got my dad and my CR5's going after sitting for a while.

1. Turn fuel on, choke on and lean bike over so that a little dribbles out the overflow

2. Very slowly push kick starter through 2-4 times

3. bring piston up so that its approaching tdc

4. Kick hard, no (or very little) throttle.
 

NavyJetFixO

Member
Dec 18, 2004
4
0
bikepilot,

thanks for the tips. Regarding the reeds, how do I tell if they seal well? I looked at them last night. Nothing broken. Some of the reeds seem to make better contact to the reed block then others. But I think we're talking only minor differences. Is that enough to matter? There are orginal too.

DP
 

Papakeith

COTT Champ Emeritus
Damn Yankees
Aug 31, 2000
6,695
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have you verified that nothing is blocking your exhaust? If the bike sits for months at a time, an industrious critter could have nested in there.
 

Papakeith

COTT Champ Emeritus
Damn Yankees
Aug 31, 2000
6,695
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John, Obviously you've watched my attempts to start my 84 CR500 before :bang: :laugh: :fft:
 

cr250can

Member
Feb 16, 2005
338
0
had a 91 cr500 that bike was a pig to start. I did everything to make it start better. top end, carb, plugs, and finally I got a new reed cage and it bad the biggest diffrence. (still took 5-10 healthy kicks cold) so I figured it was the reeds. I just got a boysen rad valve and threw it in. CR500 are just pigs to start. good luck.

I might add that when I got my 97 cr250 I loved how easy it was to start.
 

Dirt Bike Dan

Member
Aug 18, 2004
63
0
NavyJetFixO said:
Regarding the reeds, how do I tell if they seal well? I looked at them last night. Nothing broken. Some of the reeds seem to make better contact to the reed block then others. But I think we're talking only minor differences. Is that enough to matter? There are orginal too.

DP

When my reeds were bad, I could feel air blowing out of the carb. Pull your air boot off, and cover the mouth of the carb with your hand and kick it over. It should suck your hand against the carb, whereas with bad reeds it will pull and then push. I'm pretty sure this method would work for your 500. If not:
If you have the reeds already off, if there is a gap between the reed cage and the reeds, they probably need replaced. Any gap that the naked eye can see. You could try flipping them to see if that helps, but I would get new ones asap.
 

The_STiLe

Member
May 9, 2005
58
0
you say its never been rebuilt??? but it has good compresion, have you varified that with a compression tester or that because it "feels" like it has good compression???
 

NavyJetFixO

Member
Dec 18, 2004
4
0
DB Dan,
Thx for the info! I can't see any reed gaps but I'll try the carb test tonight just the same. Very frustrating...never had a problem like this. 'Bout ready to sling a rope to the truck + CR5 and get my wife to pull me down the road :yikes:

Keep the ideas coming. DP
 

magneto

Member
Nov 14, 2001
179
0
Cold start procedure for my CR5:

Turn gas on.
1. Lay bike on side for a few seconds and then stand back up. A small amount of gas should pour out of the carb overflow tubes.
2. Turn choke on.
3. Push kickstarter through slowly two or three times.
4. Push kickstarter down until piston just starts on compression stroke, let kickstart come all the way back up, take up slack and then kick through hard. (Don't use any throttle until it fires.)
5. Repeat step 4 if necessary.
6. As soon as it cranks open the throttle slightly and modulate the choke off and on until it it will run smoothly without choke.

Mine will usually start cold with 2 or 3 kicks .
 

bikepilot

Member
Nov 12, 2004
804
0
For the reads, you shouldn't be able to see an air gap between the reeds and cage at all. A very small gap that only goes a 1/4" lenght is probably not enough to make a big difference, but if the gap goes all the way across the reeds or is very big then it can make it very hard to start. The idea is that no air should be able to flow backwards. I have no idea if you can tell from your hand over the carb as I've never tried to test them this way.


Magneto, I weighed 125lbs when I had my CR5's so I needed all the help I coud get to start them (esp the 87' with no de-comp ports). Plus it was almost always a 1 kick affair for me with the posted procedure.
 

rob129

Member
Jun 27, 2004
81
0
Here is another method that has done me well:
Give her a few sissy kicks to prime the cylinder
Cycle it to where your on the compression stroke and boot the hell out of it....the key is fast and hard.....she'll light off. One thing, keep the throttle closed or the circuits will not work properly. The only time you want to open the thottle during starting is when its flooded...then hold it WOT. This is the only method that works on my 89 CR500 my 01 is easier due to the decompression scallops Honda machined into the cyclinder to aid in starting.
Have you checked your float hight? They might be too high. There are a few things that will keep the 5hundy down. Cracked/broken reeds or gap between the cage and reeds. Bad compression will also make it harder to start. Whats about jetting? It is warming and that will make things run rich...if you have not swapped over from winter settings.
 

NavyJetFixO

Member
Dec 18, 2004
4
0
CR500 Won't Start - Fixed!

To all,

I got my CR5 running! :yeehaw: :yeehaw:
Thank you for all the tips. Turns outs to be a simple fix, aren't they always? I pulled the plug and poured a couple of teaspoons of fuel directly into the cylinder, cycled the piston, put the plug in and voila, fired on 1st kick. Don't I feel like dumb A**

I think the bike sat so long that the fuel in the crankcase evaporated and the starting circuit on the carb just can't pull enough fuel into the cyl under these circumstances. I guess it just needed a little help. Anyway, all is well in CR Land, now I need to fix the lawn divots.
Ciao,
DP :ride:
 


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