[DevilDogRick]

I recently purchased it from someone who finally gave up on trying to fix it.
It will start and run just great for about 15 to 30 minutes and then it just dies like the kill switch has been hit or something. I don't think I have ever got it to start right back up but it has started back up before in as little as a minute later. Though more often than not it will take 15 minutes to a half hour before it will restart and sometimes as long as a day or 2 before it will restart.

I have tried spraying gas into the carb to get it to start right after shutting down and have had no luck with that. I have also checked to see if it has fire right after it shuts down and I do see spark from the spark plug wire with a screwdriver stuck in it and holding it near the engine though it doesn't look like a very bright spark.

Now for the real kicker is I bought a new CDI box for it and I started the ATV several times before installing the new CDI box. Once I installed the new CDI box it would not start at all and even more puzzling is the fact that it would not start after hooking the old CDI back up as well and has not started since. (which has been over a day now)
And before you ask the CDI box that I bought was not a OEM one.

The only other part I have replaced is the fuel pump as I thought maybe it wasn't getting as much fuel as it needed. I saw no need to replace any other parts as when it first starts and runs it does so perfectly.

Any help would be appreciated as it has left me walking on more than one occasion now.

 

[shadetree]

welcome to the forums. you need to buy the oem c.d.i., correct year at that !, for your atv, then you will have better luck getting it to run. from the sounds of it, you had c.d.i. prob's. then you made it worse by buying some after-market china junk that is not oem, and expecting it to run ?.nope !.

 

[Goober]

Yup the 87 Foreman has a one-off ignition system. CDI is year only Foreman model.

Don’t throw anything away you might need it.

I would say first—if it was running—OEM CDI might be bad but

How does your starter valve look? Maybe the choke is not working properly. Have you rebuilt the carb?

All OEM parts? Fuel pump, qa03a carb

Replaced fuel filter?

Was the jug getting very hot? Did the fan ever come on?

 

[DevilDogRick]

welcome to the forums. you need to buy the oem c.d.i., correct year at that !, for your atv, then you will have better luck getting it to run. from the sounds of it, you had c.d.i. prob's. then you made it worse by buying some after-market china junk that is not oem, and expecting it to run ?.nope !.

I am beginning to think you are right on this one is why I have a OEM CDI box on the way.

Yup the 87 Foreman has a one-off ignition system. CDI is year only Foreman model.

Don’t throw anything away you might need it.

I would say first—if it was running—OEM CDI might be bad but

How does your starter valve look? Maybe the choke is not working properly. Have you rebuilt the carb?

All OEM parts? Fuel pump, qa03a carb

Replaced fuel filter?

Was the jug getting very hot? Did the fan ever come on?

Not sure what the starter valve is.

The PO said he rebuilt the carb and by the way it starts and runs I am inclined to believe him as it cranks over just a few times before starting on the coldest of days and runs like a champ when it is running.

Fuel Pump is OEM and carb is original.

I am not positive about the fan running as usually when it shuts down I am busy cussing at it because of the distance from home. The good part is I live on a 250 acre farm lot so at least I am not on someone else's property when it shuts down.
I thought about the overheating possibility but dismissed it as it has shut down before in as little as a couple minutes and has not restarted sometimes for days. I never run it hard as I am usually just riding around the border of the property in the evenings looking at deer and such. It will shut down at times while moving along at a pretty good clip or just idling and sitting still. I have been doing a lot of reading and that is how I came upon the decision to try the CDI.

I do thank you guys for taking the time to reply.

 

[shadetree]

starter valve = enrichment valve, or in easy to understand terms , choke valve. start with an oem c.d.i. , give that a go, if that dont work ?, then have a look at the fuel pump. run a check on your compression. start looking at everything. down load the service manual from the site here, trust me..you will need it !..lol.

 

[DevilDogRick]

I think what worries me the most is the fact that it wouldn't start and has not started since I put the old CDI box back in. This was the second CDI box they sent me since they said the first one might have been bad. When I changed the first one around my ATV would always start after putting the old CDI box back in. That has not been the case with this one.
Can anyone think of a reason for that?
Could the new box have messed something up? A fuse perhaps if there is one to the CDI box?

 

[DevilDogRick]

starter valve = enrichment valve, or in easy to understand terms , choke valve. start with an oem c.d.i. , give that a go, if that dont work ?, then have a look at the fuel pump. run a check on your compression. start looking at everything. down load the service manual from the site here, trust me..you will need it !..lol.

Thanks Shadetree for your input. I have been reading quite a few of your responses here in the forums before posting and can tell that you are "the man" when it comes to working on these older machines as well as a couple other gentlemen here in these forums.
All of you guys advice and input is appreciated greatly.

 

[shadetree]

starter valve = enrichment valve, or in easy to understand terms , choke valve. start with an oem c.d.i. , give that a go, if that dont work ?, then have a look at the fuel pump. run a check on your compression. start looking at everything. down load the service manual from the site here, trust me..you will need it !..lol.

Thanks Shadetree for your input. I have been reading quite a few of your responses here in the forums before posting and can tell that you are "the man" when it comes to working on these older machines as well as a couple other gentlemen here in these forums.
All of you guys advice and input is appreciated greatly.

yvw . your in great hands here !.

 

[Goober]

I think what worries me the most is the fact that it wouldn't start and has not started since I put the old CDI box back in. This was the second CDI box they sent me since they said the first one might have been bad. When I changed the first one around my ATV would always start after putting the old CDI box back in. That has not been the case with this one.
Can anyone think of a reason for that?
Could the new box have messed something up? A fuse perhaps if there is one to the CDI box?

If a CDI has an intermittent connection there’s no telling when or if the connection can be restored; yes I would check the fuses. Sometimes you can rap on the CDI but I’ve never gotten that to work

Don’t throw it away—mark it “bad” and Maybe one day someone will figure out how to repair it

 

[shadetree]

I think what worries me the most is the fact that it wouldn't start and has not started since I put the old CDI box back in. This was the second CDI box they sent me since they said the first one might have been bad. When I changed the first one around my ATV would always start after putting the old CDI box back in. That has not been the case with this one.
Can anyone think of a reason for that?
Could the new box have messed something up? A fuse perhaps if there is one to the CDI box?

too give you a better understanding on how it should run ?, keep in mind..you need a few VERY IMPORTANT THINGS FOR IT TO RUN !. one: spark, two : compression, three: air, four: fuel. last but not least: timing !!. if any one of these factors is missing from the process ?, IT WONT RUN !.

 

[DevilDogRick]

You would have thought I would have learned something from working on that damned Baja I purchased. I bought it "as is" for 300 bucks and was certain I could get it running in a few days as it was in pretty decent shape. I had to buy a CDI box for it as the old one was gone. Could only buy a Japanese one as it was a Japanese Baja.
I cleaned the carb and tank right off the bat and believe it or not it fired right up and idled like a champ. Only problem was that the moment you gave it any throttle it would shut off. So I worked on the carb some more and after no luck I bought a new one. No go...still would only idle. It would start every time on the first crank and would sit an idle perfectly for about an hour with no problems. The second you gave it even the slightest bit of throttle it shut off.

Got my best friend, who is an auto mechanic, to help me and we went to work on it. I bought 2 more carbs, each one costing more than the last, fuel petcock and all the hoses going to and from the tank and carb. We didn't need a fuel pump as it was vacuum fed so then we checked every last vacuum line on it and all of them were fine. I don't think either of us had ever been stumped so bad in our lives from a gas fired vehicle.
And then we went to electrical. New stator and sending unit, coil, plug, voltage regulator or whatever they call that now. Traced every last wire on the thing and made sure they were doing ok and then we were at our wits end. My friend had 3 or 4 of his budddies, who were also mechanics, come and look at it and all of them were stumped as well though most of them were positive it had something to do with the carb. Hell even the guy who owned a 4 wheeler dealership here in the area and was a master mechanic, came and looked at it and was stumped as well!

It was at this point that my best friend was done with it and tbh I was just about there myself as I didn't know what else to try or buy.

Now for the great part as I was reading just about everything I could on forums here online about scooters and Baja's and 4 wheelers when I came across the forums here and that is when I stumbled across the answer I had been looking for.
I will of course tell you guys what was causing all of my grief but I will do so tomorrow night as I would really like to hear from a couple of you guys your thoughts on what you think might have been the cure.
I can let you know that it does tie in somewhat to what I am dealing with now on my 4 wheeler and thus why I am writing this. That and to possibly help out someone else who might have the same problem and they are as exhausted and baffled as I was.

Good Luck.

 

[shadetree]

You would have thought I would have learned something from working on that damned Baja I purchased. I bought it "as is" for 300 bucks and was certain I could get it running in a few days as it was in pretty decent shape. I had to buy a CDI box for it as the old one was gone. Could only buy a Japanese one as it was a Japanese Baja.
I cleaned the carb and tank right off the bat and believe it or not it fired right up and idled like a champ. Only problem was that the moment you gave it any throttle it would shut off. So I worked on the carb some more and after no luck I bought a new one. No go...still would only idle. It would start every time on the first crank and would sit an idle perfectly for about an hour with no problems. The second you gave it even the slightest bit of throttle it shut off.

Got my best friend, who is an auto mechanic, to help me and we went to work on it. I bought 2 more carbs, each one costing more than the last, fuel petcock and all the hoses going to and from the tank and carb. We didn't need a fuel pump as it was vacuum fed so then we checked every last vacuum line on it and all of them were fine. I don't think either of us had ever been stumped so bad in our lives from a gas fired vehicle.
And then we went to electrical. New stator and sending unit, coil, plug, voltage regulator or whatever they call that now. Traced every last wire on the thing and made sure they were doing ok and then we were at our wits end. My friend had 3 or 4 of his budddies, who were also mechanics, come and look at it and all of them were stumped as well though most of them were positive it had something to do with the carb. Hell even the guy who owned a 4 wheeler dealership here in the area and was a master mechanic, came and looked at it and was stumped as well!

It was at this point that my best friend was done with it and tbh I was just about there myself as I didn't know what else to try or buy.

Now for the great part as I was reading just about everything I could on forums here online about scooters and Baja's and 4 wheelers when I came across the forums here and that is when I stumbled across the answer I had been looking for.
I will of course tell you guys what was causing all of my grief but I will do so tomorrow night as I would really like to hear from a couple of you guys your thoughts on what you think might have been the cure.
I can let you know that it does tie in somewhat to what I am dealing with now on my 4 wheeler and thus why I am writing this. That and to possibly help out someone else who might have the same problem and they are as exhausted and baffled as I was.

Good Luck.

gonna go out on a limb here, and say the fuel tank was not venting..allowing enough fuel to the carb ?.

 

[DevilDogRick]

I had someone suggest that as well shadetree but I never got the chance to try it as whet I saw here in the forums was someone talking about the timing on one of the 4 wheelers and I thought "Timing"? Didn't even know there was timing on a 1 cylinder vehicle. Well except for the timing of the piston being in the right place when the plug fires but beyond that I didn't know they had any other timing to be concerned about. But what he meant was the timing advance when the engine was revved up higher. And what controls that? The CDI box.

So I went out on a limb and ordered another CDI box from a different seller on E-bay. I would like to say I am exaggerating shadetree but I was actually in tears the night I got the new box and installed it and heard that engine idling faster than it had ever done before as I knew right then the problem was solved.When I got in and mashed the gas pedal and the engine roared to life I was still in tears. You guys have to realize that I had been working on the damn thing for about 3 months now and had spent hundreds of both hours and dollars to get to this point.

From what I understand from my buddy I had the biggest nightmare to any mechanic happen to me and that was to buy a defective new part. But with me it just happened to be the very first part I had bought. That made it even worse imo.

So what I said about this story kind of being like my problem now is that I bought a "new" defective CDI box made in Japan and it bit me in the ass again! Though in my defense I had no choice with the Baja as it was made in Japan so OEM parts for it are all going to "made in Japan".

Btw I will have my new Honda CDI box tomorrow and will let you guys know how it goes.
I also thought I should let you guys know that the seller I bought the first CDI box from sent me another one saying that he had people returning his boxes and some had success with a second box he would send them if that is what they wanted.
I installed his second box tonight and does anyone want to take a guess on what happened?

 

[DevilDogRick]

I got the new OEM CDI box. Hooked it up and nada. No start, no fire, nothing. It has not ran since the day I switched out the CDI boxes a couple weeks ago. Either with a new CDI box or the old one installed. I am at a total loss here fellas and any help would be deeply appreciated.

Where would you go from here shadetree?