90 CR250 won't start

[joh9356]

Okey Dokey,

I have all of the gaskets and seals. I have draw-filed both case halves, cleaned every part and will begin reassembly tonight.

I found out on the earlier rebuild(if you want to call it that), some idiot(read my previous posts and you will see why I call this person an idiot) also cranked down the cylinder on the cam spindle, cracking and bending it. It looks reusable, so I am going to fire the spindle head, reshape it, and tig weld the crack. If it doesn't work, off to the dealer I go.....again.....

We'll see how that goes, so I am going to finish the lower end tonight and reassemble the cylinder tomorrow.

Jim

OK, so far, this engine on the previous rebuild:

1) bent and cracked cam spindle
2) destroyed and reshaped and rebalanced crank counterweights
3) screwdriver pried case halves
4) screwdriver pried cylinder
5) completely screwed up carburetor(removed o-ring and washer from air idle screw, frozen plunger on fuel valve, completely wrong jetting)
6) engine bearing set from CHINA!!!! :ohmy:
7) grooved out clutch basket

All of these things have been either repaired or replaced as of now.


---Note, I went ahead and ordered and received a new cam spindle from service honda, it needed replacing, the HPP system works smoothly now.

 

[joh9356]

OK, does anyone have a very large hammer?

I just got through rebuilding the entire engine. Kicked it three times and it roared to life! Sounded pretty good for the first 30 seconds, then it started bogging. Let it cut out, kicked it once and it started right up again, then it sounded like it bogged really bad. I could barely get it to rev up.

After the last cut out, it never started again. It started flooding again. :pissed: :pissed: :pissed: :pissed: :pissed:

I do not want to sink any more stinkin money into this thing.

Should I replace the carb?

Should I replace the reed valve assy?

 

[joh9356]

OK, I'm thinking carb. My theory is that this thing is sucking in more fuel than it can burn. Sound good? Like I said before, Keihin said it is probably worn out. I also don't think I mentioned that this bike has never even attempted to idle either.

Well, I certainly don't feel bad about the rebuild because it really needed it, if for no other reason to replace all of the damaged and missing parts from the previous rebuild.

I guess my next step is a PWK

 

[nickyd]

wow. this is quite a thread. Sorry if I am playing captain obvious - but do you have all the necessary items in place (ie, air filter, correct gas mixture, etc) - in my years of working on bikes, its always the easy stuff that messes me up....NOW, before you REPLACE the carb, what are the settings? Are they back to stock? You mention that the bike ran for 30 seconds and then died - you then said you think its getting too much gas...any chance, its NOT getting ENOUGH gas? is the petcock ok? float ok? Look past the fact that Keihin said its "probably" worn out...it made the bike start but not stay running...WHAT Does the silencer look like? Pull it apart and repack it - its only $8 to do and I bet its a freakin mess in there....what you describe is what happens after I wash the bike and forget to pull the plug out of the exhaust - it barely runs, you can't rev it and it dies....before you sink more money in it, test this stuff out....we know you have compression. we know you have spark. We have no idea what your fuel and air is like. I'd start there - and keep in mind what did Keinhn tell you? the needle had issues? the needle shouldn't be affecting you at idle.

 

[joh9356]

Hey Nickyd,

Thanks much for the reply, I am at my wits end here.

I stripped the carb down again last night, and this time I got carbparts on the phone and they gave me the correct specs, but the problem was that I have a PJ38, and they said from the rim of the carb to the TOP of the entire float should be exactly 16mm. Well, in my case, the float that is in this carburetor maxed out at 24mm, and that is completely depressed by pressure of my hand against the top of the bowl, hardly the state for proper measurement. He said I had the wrong float, could this be possible? How can someone get the wrong float and everything seem fit and move ok?
OK, so anyway, instead of measuring it this time, I eyeballed it, carefully tilted the carb on it's side until the float tang just contacted the float valve, not pushing the plunger in, and adjusted it until the float was at it's highest without the fuel level going over the overflow nozzle. I checked all of the other settings on the carb, and they looked just fine, blew out all of the air passages, etc. I have rebuilt hundreds of carbs, albeit, they have been automobile carbs, but I completely understand their functionality.

Here are the default specs as compared to my specs:

PJ38:

Stock/ Mine:

needle- 1468N or DGJ/ 1370N or CGL (leaner)
Main- 168/ 170 (richer)
slow- 62/ 55 (leaner)
slide valve- 6/ unknown
__________________________________________________

At this point after kicking it a few times, I pull out the plug, and again, it is cold fouled/washed out. I already replaced the CDI box and it didn't help the spark any. Oh, and BTW, I also remove the pipe after this too, and it is a little wet with raw fuel too, not much, but enough to know it is not igniting in the cylinder.

So we know I have rebuilt the engine, I have repacked the silencer, and checked out the pipe, replaced the pipe gasket at the cylinder, along with the exhaust springs, rebuilt the carb, tested the reed valves, new air filter (tried starting it with and without it on), fuel mixture is 93 octane 32:1 synthetic as recommended by my dealer.

As for the needle issues, what they were saying is that the needle wallowed out the body where the main jst seats, but, like you said, that should have no effect on idle.

Now, when I say that I have spark, I have a PVL aftermarket ignition. When I pull out the plug and kick it over, it sparks 70-80% of the strokes. I spoke to Penton Imports (they import the PVL ignition from Germany) and they said that this is normal, is this true? If you pull out your plug, and kick it over do you see spark every stroke? I have a bad feeling about this. That is also why I went ahead on my dealers advice and bought a new CDI box for it, but like I said before, no good. What about the stator, has anyone seen a bad stator act this way? I am thinking about sending it in again and having it tested, again. It has impedence(resistance) within limits, but I keep wondering, what does the spark look like INSIDE the cylinder?

Anyhow, you guys have no idea how much I appreciate your input on this. Keep feeding me ideas, please, NickyD, captain obvious isn't too obvious for the likes of me, I am willing to listen to the smallest of recommendations, as long as they don't require money without thought, like parts replacing.....


Anyhow, please guys keep giving me advice, I am desperate!

Jim

 

[nickyd]

Jim....I'm thinking.....if the float was not stopping the flow of gas in, the overflow tubes should pour out gas....are the overflows on the carb open? ie, not clogged?

what happens to the bike if you put in a fresh plug, turn off the gas and spray some carb cleaner in the throat of the carb (right in the reeds) - DISCLAIMER...we all know this is not the ideal way to work but in moments of desperation (such as this), I am forced to try it....if the bike fires, you have a fuel problem...if not AND assuming you still have compression, you might have a spark issue...

OH hey wait a minute...you said you painted the frame - do you have good grounds? they are not painted over are they (really don't think this is the issue...just a wild stab)

 

[mobrown]

Hmmm...

Hey JOH, what you're going through sounds very frustrating. You're so knowledgeable about what you're doing that it seems hard to believe that you haven't gotten it running right yet... plus I find myself fascinated with the whole conversation!

Anyhoo, I have a 91 CR250 that I just completely built the top end on. I even took apart the powervalves and cleaned them out despite not having any idea how they worked (used the manual and have a sound mechanical aptitude :-). Anyway when I put it all together it and started it it did exactky what yours' did. What I ended up doing is starting it and letting it run as long as it could then changing the plug and doing it again. It took (4) plugs to finally get it to come completely to life and I think the reason was all the 2-stroke oil I used in lubricating the cylinder, piston and the valves in the HPP during assembly... it simply had to burn it all out.

Also I noticed that you can put the spindle that actuates the linkage in the HPP in wrong and still have it go together. And the cam that works the whole HPP (the part that's in the bottom half) can be tricky to engage.

Sorry for the long thread but I just thopught I'd share my experience with you. Good luck dude... you so rock!!

 

[joh9356]

Thanks Nickyd,

1) overflow lines are good, carb is not flooding, I checked the fuel level to make sure, I also got a picture of the correct float for this carb, and it is correct, I am waiting to hear back from Keihin for this specific model on what to do.

2) Hmm.. haven't tried the spray yet, and I have a new can of carb cleaner in my shop...:)

3) Grounds are good, I cleaned them straight to bare metal with my dremel tool.

 

[joh9356]

mobrown,

thanks for the reply. I'm not all that knowledgeable, if I were it'd probably be running ;)

Anyway, I would have kept it running, but it kept bogging and bogging, I finally really just couldn't keep it running, so I let it off, and it never started again. Sounds weird, huh? I wonder if it is the stator breaking down? I am sending off the entire ignition system back to penton tomorrow and they are going to rebench test the entire circuitry and system.

Yeah, I studied Erics recommendations on how to engage the HPP system properly and it is working ok, especially after installing a new cam spindle!

Guys, you have no idea how much I appreciate your helping me out here.

Jim

 

[mobrown]

You're gonna love it!

Hey Jim... when you get it running you're gonna be excited! My 91 will smoke a lot of these newer bikes. Now I'm not the most couragous or skilled rider out there but if I was this machine would certainly hold its' own. :cool:

Keep on chuggin' you're figure it out, I have no doubt. BTW did you paint your frame and/or put new plastics on it? I would like to make mine look good and keep it even when I get a newer one. Any suggestion?

Mo

 

[joh9356]

Well, I must sheepishly admit that I did not repaint the frame Shasta white as was original, I repainted it neon red. I can get an entire plastic kit for this bike for 99.00 bucks minus the tank, which I can't justify the cost as of yet. (Can't remember where I saw this, but you can see the parts from White Brothers' website)

But hey, thanks for the tip on the strength of this bike, makes me feel better if and when I can get it running.

I still need to paint the upper frame. THe only suggestion or advice I can give on this frame repainting is that due to the flexability of the type of paint they used, sandblasting or beadblasting won't take it off at all! You HAVE to hot tank the frame in a caustic chemical solution to remove all the paint. I didn't. I just scraped off the paint as best I could, sanded it down, and repainted it.

I can't wait to get plastic for it though, I plan on doing the entire bike back in neon red.

Jim

 

[nickyd]

who put that ignition on? Any chance the plate is on wrong and your timing is off?

 

[joh9356]

I did. After the rebuild, I made sure I timed it right and called Penton just to make sure. Seems it was timed right. All the parts are in the mail to be tested, so we'll see what comes of that.

I'll tell you what though, I am beginning to wonder if anyone has had experience with these ignitions, if they are known to be good with them. Rich said he has not had any experience with them and Eric had a picture of one in his handbook, but I have not heard from him on this particular case yet. I don't know if he was just referring to it, or if he has ever dealt with them before.

If it turns out the ignition system checks good, but still can't get my bike to run, I hate to say it, but I will look for an original ignition system just to replace mine. I can get the stator from Ricky Stator for 125, a used working CDI for 95, a new coil for 50, but I'll be darned if I can find a used flywheel for this thing anywhere, that's why I am going ot such extent trying to get this PVL system working.

Of course if I get the flywheel from Service Honda, they won't separate the stator and flywheel, so my best price for those are 322.00. All in all, if I replace the entire ignition system through Honda, I am looking at 500 bucks. Something I really don't and can't spend right now.

 

[gowen]

joh9365, I use a PVL ignition on my KX500. I don't have time to run through the pages, but it sounds like you MIGHT have the timing backwards. It was a TOTAL bitch to set the timing on my KX so, I'm assuming you might have the same. PVL makes an awesome ignition, give me some feedback. I've worked and tweaked mine.

If all else fails, I have a friend that was wanting to put a PVL on his '89 that I sold him. I bet he would trade you out. We will see what PVL says, but I'm assuming it is your timing, almost betting. Either that, or you are just not kicking it hard enough. That was a major deal on my KX, it takes a bigger kick for a smaller flywheel.

 

[joh9356]

Gowen,

Thanks for the reply, I'm glad to meet someone else who is also running the PVL.

It's definitely not the timing, I worked closely with Penton to make sure it was set up right. The Honda's crank turns CCW, so I use the right hand timing mark. And best case for the PVL is said to be 2mm BTDC, so it was a good starting point.

You are right though, you have to kick this thing hard. Like I said ealrier though, it roared to life after the rebuild just fine, then after 30 seconds it started bogging, then just got worse and worse until it kicked out. I am just eliminating the problem being the ignition system, I hope.

Let me ask you a question, does your plug spark every revolution with it out of the head when you kick it?

How did you have to set your timing? Why was it such a problem, would it just completely not run at one setting, then fine on another? Do tell.....

 

[gowen]

Gowen,

Thanks for the reply, I'm glad to meet someone else who is also running the PVL.

It's definitely not the timing, I wThe Honda's crank turns CCW, so I use the right hand timing mark. And best case for the PVL is said to be 2mm BTDC, so it was a good starting orked closely with Penton to make sure it was set up right. point.

You are right though, you have to kick this thing hard. Like I said ealrier though, it roared to life after the rebuild just fine, then after 30 seconds it started bogging, then just got worse and worse until it kicked out. I am just eliminating the problem being the ignition system, I hope.

Let me ask you a question, does your plug spark every revolution with it out of the head when you kick it?

How did you have to set your timing? Why was it such a problem, would it just completely not run at one setting, then fine on another? Do tell.....

Yes, mine sparks every revolution. Penton is wrong about that, it should be firing lots. Timing, wow, being that it was on a 500, my problem was kickbacks, if the timing was slightly off it would kick back like somebody took a baseball bat to your foot. It would just not start due to the timing being too advanced. But, it sounds like you have it down and that there is something defect in the electrical if it is only firing on and off. I have had no issues with my KX so far with it, except I just froze it, due to alot of reasons, but not the ignition. Good luck with it, I think Penton shoudl take care of you. :cool:

 

[joh9356]

Cool, thanks, I sure hope so. This thing is frustrating the pee out of me.

I'll let you know how it goes.

 

[joh9356]

OK, Penton called me and said everything was perfect. The PVL ignition system jumps an 8mm spark at 375 rpm consistently. So we can eliminate the ignition system.

I just ordered a Boyesen RAD valve and it will be here Tuesday.

At this point, I am slowly just going to replace everything until it works.

 

[nickyd]

oh you're back again...with no luck in the ignition....crap. I was hoping that was the problem....where are they testing the ignition? in the cap? you checked to make sure the spark is getting from the wire into the cap right? I think you did, but can't remember.

 

[joh9356]

No, they have a testing facility in ohio, pretty state of the art, so it definitely is not the ignition.

Anyhoo, I received the boyesen RAD valve yesterday, and stuck it in !!!! :nod:




And........ it did the same thing!..... :bang:



It cranked right up and ran fine , but again would not idle. It ran twice, again, and wouldn't start after that....again.


I am buying a carburetor :blah:

Will let you guys know when I get it as this has drained my bank account :|


Jim

 

[gowen]

you sure about your compression??? Check your compression before buying a carb. It does not sound like a carb problem. Unless fuel is pouring out the carb, it shouldn't be flooded enough to not start and act like that. When a bike has low compression, they usally fire (or try) and then die. When you rebuilt, it doesn't matter if you replaced the piston and rings, measure the compression. I've lost top-end the first few minutes of breaking them in, due to rod bearings collapsing and/or dirt scoring the cylinder.

 

[Butane]

My buddy suspected carb and ignition problems on his CR250 so he push started it to eliminate a few things have you tried that yet?

 

[nickyd]

You replaced the top end right? did you spec the measurement between the piston to cylinder? i wonder if the clearance isn't enough and when she heats up she starts to seize....just a random thought. why would a bike run for a bit and then stall - HOW long does it run?

 

[The_STiLe]

the spark plug lead and the unit at the end of this, it should be unit sealed together?? i would change that before anything it is a inexspensive part, my friend had a husky and he changed just about everything else before that and that ended up been the problem. if that doesnt work get your mate and get him to tow you around behind his car until the fu*ker runs.and i admire your commitment i would have smashed it to bits ages ago.

 

[joshualeeusmc]

Man..you are definitely egaged in a battle. I'm reading this thread like an intense action story. You have got to keep working at it, you will get it eventually. Just keep us posted on what is happening. In my opinion this is better than American Idol!