Need help with 85 Honda 250R ATC

[rmcollector]

Morning everyone, this is my first post on here and wanted to see if I can get some help with my 1985 Honda 250R ATC.

Within the last several months I did a fresh top end on it, along with a rebuild of the water pump. I did a rebuilt of the water pump due to the mechanical seal leaking. I have ran a full tank of gas in it (32:1) and have found it is running way too rich and adjusted the carb and float. Got it running very good for 10-15 min and then it started to run too rich again. It sat for several days and I noticed several drops of oil dripping out of the carb overflow hose. I took the carb off and there was alot of oil inside. I cleaned it out really well and started it up and it ran great for about an hour with no problems at all. It then suddenly bogged out on me and I realized it needed gas. After I put a gallon of gas in it will not start. I also noticed it used ALL of the coolant that was in the radiator after riding for an hour! After I discovered this I took the cylinder off and inspected the wall and piston, everything is in great shape just like when I put it back together with no damage. Current compression is 158 psi. I am getting spark when tested. I am running the 86 flat carb, not the 85 carb. This is the first time this trike hasn't started for me since Ive owned it. Any help with this would be greatly appreciated! Thanks, Rick

[yaegerb]

What does your gear oil look like?

[rmcollector]

Doesn't look much different than when I put it in, slightly darker. Running Pro Honda GN4. I did notice when I took the pipe off the head it had a strong smell of gas with alot of oil inside.

[yaegerb]

My opinion but I would be running a different oil than a gn4. The make 80/85 gear case oil that is much better for your 2 stroke. So if it’s not leeching into your crank case you must be either burning it or leaking it from somewhere. Have you noticed white smoke come out of your tail pipe?

[atc007]

Compression is low. Not the problem as you mentioned. But 185-190 is much preferred. Coolant disappeared. Chase that. Sounds like you have at least 2 gremlins fighting you. Head gasket and maybe worn carb. Assuming you are not ingesting tranny fluid,which Brendon mentioned. After all is said and done. it could also be the CDI box. But for right now. We know other places need attention first.

[rmcollector]

Oh ok, no I haven't had any white smoke come from the tail pipe. It ran great for that hour of riding, but like I mentioned in the post it just bogged out and once I put gas back in it will not start. You think it could be a carb issue? I have cleaned it thoroughly, but it has always had that small drip or two coming from the overflow throughout the day. I bought a 38mm knock off carb for $36 bucks that I am waiting on, I am not sure if it will get it started, but if so...then im guessing the carb is the problem. If it works find after that I am going to buy the Genuine Keihin, just want to see first where im at.

[rmcollector]

That's interesting, I had a 86 TRX 250r that had compression of 150 psi and it ran perfect and always started 1-3 kicks.

[rmcollector]

What am I looking for with the head gasket? It is new, oem gasket. No leaks. Sealed tight with copper sealant.

[efhondakid]

32:1 is wayyyyy to rich on oil if you ask me. I run all my 2 strokes 44:1, 50:1 on the race machines. Royal Purple ATF in the cases on them all as well.

Using coolant means you have a leak somewhere, if you have a small leak in the head gasket you won’t see white smoke with such a pig rich oil mixture, but the top of the piston and head will be clean from the coolant cleaning the carbon.

[HondaRidr]

32:1 is fine and so is 158 psi compression. Are you leaking coolant from any of the hoses or somewhere on the radiators?

[rmcollector]

32:1 is fine and so is 158 psi compression. Are you leaking coolant from any of the hoses or somewhere on the radiators?

Yes, there was coolant leaking from a old radiator that was on there, it was replaced and then was running fine for that hour of riding. Not sure where there is a leak but that coolant was all gone after the hour of riding. I rechecked the compression last night and got it up to 167 psi. Just can't seem to get it running again.

[rmcollector]

Meant to send motor pic, let me see if I can find it.

[yaegerb]

Anything below 170 is NOT fine on a 3rd gen 250r. Are you taking compression correctly with the throttle wide open on every kick? Take the compression reading again with the throttle wide open. If you are still below 170, add a teaspoon of premix oil in your spark plug hole then take another reading. I will bet the compression increases+\- 10 psi. If it does increase one of two things is happening. Your “fresh” top end is incorrect or you haven’t put enough time on the cylinder to seal the rings. If you used wiseco they usually take 1.5 tanks of gas to properly seat. Also, your coolant doesn’t just vanish. Refill it and find where your leak is. If it’s not weeping from a line or around the head then you are burning it up in the combustion process from a failed head gasket. If it is not starting endure you are getting good spark by grounding your plug to your head. Spark should be fat and blue in color.

[rmcollector]

Anything below 170 is NOT fine on a 3rd gen 250r. Are you taking compression correctly with the throttle wide open on every kick? Take the compression reading again with the throttle wide open. If you are still below 170, add a teaspoon of premix oil in your spark plug hole then take another reading. I will bet the compression increases+\- 10 psi. If it does increase one of two things is happening. Your “fresh” top end is incorrect or you haven’t put enough time on the cylinder to seal the rings. If you used wiseco they usually take 1.5 tanks of gas to properly seat. Also, your coolant doesn’t just vanish. Refill it and find where your leak is. If it’s not weeping from a line or around the head then you are burning it up in the combustion process from a failed head gasket. If it is not starting endure you are getting good spark by grounding your plug to your head. Spark should be fat and blue in color.

Yes I have been checking compression with the throttle wipe open on every kick. I will check it again in the morning and see what I come up with. Thanks for the reply.

[Doug8765]

I think your crank seals are bad it creates the rich lean condition. You can run that motor at 20:1 like it says in the manual. That is NOT THE problem. If the coolants not a weird color and carb is clean. New spark plug .. check reeds too if that’s all good it the crank seals . Pretty common


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[Doug8765]

I wore out 12 of those motors with 4 different bikes


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[rmcollector]

Ok so I did the compression test again this morning, after 20 kicks with the throttle wide open im at approximately 160 psi. After adding a teaspoon of oil in the spark plug area im at approximately 175 psi. The head gasket is sealed. No leaks. Everything is tight. It's brand new, oem gasket. With adding the teaspoon of oil, this tells me there is a head gasket leak? Im not seeing it. It ran perfectly fine before with a average of 150-160 psi. I don't believe this is preventing it from starting.

[yaegerb]

That means your rings/bore is either worn to the point of not sealing or or rings haven’t seated yet. Have your grounded your spark plug to your head to see if you are getting spark?

[Outlaw #24]

Kick it over with the radiator cap off . If the head gasket is leaking it will bubble through the fluid in the carb just from kicking it over a few times. You say it won't start and carb is oily. This might be that your filter has to much oil on it. Check the clip on the pin in the carb to make sure it isn't broken. Check the reeds make sure they are good because this should shut and open because it is a Valve and if it fails will let fluid go in both directions. the seal may be bad on the clutch side and letting oil into the crank case area. The seals should be changed anyway if it has never been done or you will eventually be rebuilding the top end again. Seals on a 85 -86 are 30 years old. You fuel mix is probably ok as you have said it jetted out good. Check it out and get back to us!

[rmcollector]

That means your rings/bore is either worn to the point of not sealing or or rings haven’t seated yet. Have your grounded your spark plug to your head to see if you are getting spark?

Yes I checked the spark plug by grounding it to the head and I am getting spark. I noticed when I was kicking it there was a strong smell of gas coming out of the spark plug hole.

[rmcollector]

Kick it over with the radiator cap off . If the head gasket is leaking it will bubble through the fluid in the carb just from kicking it over a few times. You say it won't start and carb is oily. This might be that your filter has to much oil on it. Check the clip on the pin in the carb to make sure it isn't broken. Check the reeds make sure they are good because this should shut and open because it is a Valve and if it fails will let fluid go in both directions. the seal may be bad on the clutch side and letting oil into the crank case area. The seals should be changed anyway if it has never been done or you will eventually be rebuilding the top end again. Seals on a 85 -86 are 30 years old. You fuel mix is probably ok as you have said it jetted out good. Check it out and get back to us!

I did this and there were no bubbles. The air filter is dry. No oil at all. The clip on the carb is fine. I am just confused here as to why all of a sudden after riding for an hour that this thing refuses to start back up. I put a new 38mm knock off carb on this evening to see if it was the carb and I am having the same problem. So im guessing that has been ruled out. Can bad crank seals make it not start, or will it just have poor engine performance while it's running?

[rmcollector]

Forgot to mention, when I took the spark plug out it is wet with gas.

[yaegerb]

It could be a sheared woodruff key on the stator side. Do you have a flywheel puller? You may want to pull off the flywheel and ensure the key is still there and in good condition.

[rmcollector]

Yes I am going to have to get to it later into the weekend or next week. The stator can't be bad if I am getting spark, correct? Just want to see if this is something that needs to be looked into while I take the cover off. You think the crankcase is possibly flooded with gas preventing it from starting? I would think though after draining the oil it would have gas in it, which wasn't the case when it was recently drained. It was nearly as clean as when I put it in before my hour of riding.

[yaegerb]

Doubtful that the stator is bad. I also doubt the crankcase is flooded with gas preventing it from starting.

[Outlaw #24]

Did you check the reeds?
The Key can be bad and still send a spark it would just be sparking at the wrong time so Yes the woodruff key can be bad and still have spark.
Everybody with a 2 stroke should shut the gas off after riding because when you shut the engine off after it's been ridden the engine is hot and when it cools the cylinder can actually go into a vacuum and pull the gas through the carb and draw it into the engine and it will flood the bottom end with fuel. This doesn't happen every time but it does happen so, Always, always, always shut the gas off. If you are a racer JUST don't forget to turn it on again!

[rmcollector]

Did you check the reeds?
The Key can be bad and still send a spark it would just be sparking at the wrong time so Yes the woodruff key can be bad and still have spark.
Everybody with a 2 stroke should shut the gas off after riding because when you shut the engine off after it's been ridden the engine is hot and when it cools the cylinder can actually go into a vacuum and pull the gas through the carb and draw it into the engine and it will flood the bottom end with fuel. This doesn't happen every time but it does happen so, Always, always, always shut the gas off. If you are a racer JUST don't forget to turn it on again!

When I put some parts back together a few months ago the reeds were taken out and cleaned. They looked fine. This is something I did not replace when I put things back together. I did not see any light through them. As far as how old they are, I do not know. If I take the reeds back out, what am I looking for? Seems unusual that the reeds would just suddenly fail and cause it not to start. I would think it would start...but have a harder time starting if the reeds are bad?

[rmcollector]

I had a chance to take out the reeds today and found after I took them out they are completely saturated with gas. Inside the intake port is also saturated. Do these reeds look okay? If it is flooded with gas, how do you get the gas out of the crank?




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[yaegerb]

Those look original. Are they metal? If so they are the original spring steel and I would replace them if you can see light through the slit between the reed petal and reed block. Shine a light into the mouth of the cage and look for light peering through. If you seek light, get a set of boyesen pro reeds. If you do replace them you won’t need the reed stoppers. You could suck the gas out with a mighty vac and a long thin hose. Again I doubt gas in your crank case is a problem. I rarely see this happen in 250rs. It’s more prevalent in Banshee’

[rmcollector]

Yes they are metal. I checked to see if light was coming through, and to my surprise there is one side that had a decent amount of light coming through while the other side did not. Didn't see this light when I checked them several months back. Not sure if this is the problem to it not starting but I am going to change them out for sure.

[rmcollector]

My suspicions are correct, the crankcase is completely flooded with fuel. I am going to get a siphon pump to try to get most of it out. Anyone else have this happen to them before? What can be the reason as to why the crank is flooded? The fuel on the carb is always turned off on the carb, but the overflow does have about 3-4 drips a day while it is not running. The float has been adjusted correctly.

[yaegerb]

No I have not experienced this on an r but I have never had one leak as you are experiencing. How much gas is actually in the crank case? I would love to see a picture of this.

[shortline10]

I see this all the time , either your petcock is bad or your float valve isn’t sealing correctly .
I start off with a large syringe to remove the fuel and a little compressed air to get it completely dry .

[atc300r]

I had a similar experience like this on my 86 200x. The little spring pin on the needle stuck in and the gas started filling up the airbox.I replaced the needle and its all good.

[rmcollector]

I got all of the gas out of the crank this morning. This is only half of what came out. Waiting on the reeds and cylinder gasket to come in and going to put it back together. Im hoping it will start. Will let you guys know.

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[atc007]

Maybe I missed something. If you are waiting on a cylinder gasket. Get your cylinder to a reputable machine shop to get your bore squared away and matched to a piston. Also,if your air filter is dry with no oil. That is not good. Air filters rely on oil to filter dirt. They need to be clean,but oiled for filtration.

[Outlaw #24]

Your petcock is leaking through because it is bad and won't shut the fuel off or you didn't get it shut when you shut it off! the needle fuel valve needle inside the carb didn't shut either, possibly wrong float setting. Gas tank is higher than the engine so it will drain into the engine. Dry it out and put the new reeds in. Lubricate the rod bearings now because they have been laying in gas. Oil you filter. Foam gets oiled and K&N's get spray oiled Lightly. Foam gets saturated and ring it out to get all of the excess oil off (Squeeze the oil out). Good luck and let us know how you made out!

[rmcollector]

Maybe I missed something. If you are waiting on a cylinder gasket. Get your cylinder to a reputable machine shop to get your bore squared away and matched to a piston. Also,if your air filter is dry with no oil. That is not good. Air filters rely on oil to filter dirt. They need to be clean,but oiled for filtration.

The cylinder has been stored for years and has less than 40 hrs with a stock bore, why would I need to get it matched to a piston? As far as the air filter, yes it is lightly oiled, I just meant in a previous post that it wasn't saturated in fuel and is "dry".

[rmcollector]

Your petcock is leaking through because it is bad and won't shut the fuel off or you didn't get it shut when you shut it off! the needle fuel valve needle inside the carb didn't shut either, possibly wrong float setting. Gas tank is higher than the engine so it will drain into the engine. Dry it out and put the new reeds in. Lubricate the rod bearings now because they have been laying in gas. Oil you filter. Foam gets oiled and K&N's get spray oiled Lightly. Foam gets saturated and ring it out to get all of the excess oil off (Squeeze the oil out). Good luck and let us know how you made out!

The petcock has been replaced about 2 months ago with a oem one. No leaks with the new one. As far as the carb, this is the part I am having trouble with. I cannot seem to pinpoint it. Can certain parts inside the carb go bad that cannot be replaced on the Keihin? I have the 85 model, but I am using the 86 flat slide Keihin carb.

[yaegerb]

Why don’t you just get a 38mm Keihin. They work well. Get a genuine one, not a knockoff.

[rmcollector]

Why don’t you just get a 38mm Keihin. They work well. Get a genuine one, not a knockoff.

lol...yes I am, I was just being cheap. I plan I getting one in the next week or two. Why not the stock 34mm Keihin? Or possibly a 35mm? I am only running fmf, everything else is stock. I put those Boyseen reeds on that you recommended and they fit perfect.

[Outlaw #24]

You probably don't need a bi carb but the float may not be set correctly and letting fuel go through the shut off valve inside the carb. The little rubber point on the end maybe deteriorated and especially if you have used gasohol in your fuel. The Alcohol in your fuel is a no no. Alcohol deteriorates all aluminum and makes rubber swell and become flimsy is hardens is up after the fuel dry's up . You did say it had been sitting! Also even though you said that a new pet cock was installed does not mean that it is shutting the fuel off. Unplug the fuel line from the carb and check out specifically where it shuts off and make darn sur it is shutting off. Let us know what you find out!

[yaegerb]

lol...yes I am, I was just being cheap. I plan I getting one in the next week or two. Why not the stock 34mm Keihin? Or possibly a 35mm? I am only running fmf, everything else is stock. I put those Boyseen reeds on that you recommended and they fit perfect.

When I build them I always use a 38. They are an all around great carb, easy to jet and provide enough fuel when you want to upgrade from stock down the road. Down jetted, they also work well on stock platforms.

[rmcollector]

It could be a sheared woodruff key on the stator side. Do you have a flywheel puller? You may want to pull off the flywheel and ensure the key is still there and in good condition.

So I got the motor back together today after getting all the gas out of the crank. Still won't start. I remember you mentioning the woodruff key and decided to take the flywheel off. Once I got it off there were little pieces of metal in the flywheel that look to belong to the key. I have never looked at a woodruff key, but I am going to say this is damaged from what I see? 255211255212

[yaegerb]

So I got the motor back together today after getting all the gas out of the crank. Still won't start. I remember you mentioning the woodruff key and decided to take the flywheel off. Once I got it off there were little pieces of metal in the flywheel that look to belong to the key. I have never looked at a woodruff key, but I am going to say this is damaged from what I see? 255211255212

Yup, and that’s one if the main reasons why you aren’t firing. I can see where the flywheel has been turning on the crank spindle. Get a pic and a small hammer and lightly tap the old key bits out of the groove and get a new key. You can still buy the key for that motor on partzilla.

Also, make sure the keyway in the flywheel isn’t damaged in some way. There a reason why that key sheared like it did.

[rmcollector]

Just got it out earlier and ordered a oem key off eBay for $7 bucks. I looked inside the flywheel at the keyway and there is no damage at all. Do these things just randomly go bad?

[yaegerb]

Just got it out earlier and ordered a oem key off eBay for $7 bucks. I looked inside the flywheel at the keyway and there is no damage at all. Do these things just randomly go bad?

No, it’s usually from someone putting a motor together not know what the hell they are doing. Or they lose the key and they just cram whatever they can find in the keyway.

[Outlaw #24]

Glad you found the Problem!!! Sometimes this happens and sometimes it doesn't. Good luck and let us know how you make out with this.

[rmcollector]

Got the woodruff key installed and put it back together, turned the fuel on the carb and had it started for no more than a second...then it died. It did this 2 times before I decided to take the spark plug off to check it, it was soaked with gas. I took the header pipe off to look inside at the piston and it is carrying all gas and some oil with with it again.

Carburetor flooding crank? What else could it be? It ran a total of 2-3 seconds max. The overflow on the carb has no gas coming out when it is turned on. I am at a loss here. I am going buying a new carb, but just wanted to get any feedback that anyone may have on this.

[yaegerb]

Got the woodruff key installed and put it back together, turned the fuel on the carb and had it started for no more than a second...then it died. It did this 2 times before I decided to take the spark plug off to check it, it was soaked with gas. I took the header pipe off to look inside at the piston and it is carrying all gas and some oil with with it again.

Carburetor flooding crank? What else could it be? It ran a total of 2-3 seconds max. The overflow on the carb has no gas coming out when it is turned on. I am at a loss here. I am going buying a new carb, but just wanted to get any feedback that anyone may have on this.

Put a clear hose on your puke tube fitting on the bottom of the carb. Have enough hose so you can bend it up past the float bowl. Loosen the bowl screw and watch how high the fuel flows into the tube. If the fuel flows up and reads higher than the top of your float bowl you have an issue and need to adjust your float height or the viton tip on the needle won’t seal anymore and it needs to be replaced.

Also while you were in missing with your flywheel did you set the pulse air gap by chance? A business card should fit snugly between the flywheel indicator and the pulse generator.

[rmcollector]

Put a clear hose on your puke tube fitting on the bottom of the carb. Have enough hose so you can bend it up past the float bowl. Loosen the bowl screw and watch how high the fuel flows into the tube. If the fuel flows up and reads higher than the top of your float bowl you have an issue and need to adjust your float height or the viton tip on the needle won’t seal anymore and it needs to be replaced.

Also while you were in missing with your flywheel did you set the pulse air gap by chance? A business card should fit snugly between the flywheel indicator and the pulse generator.

Ok, no, I did not do this when I put it back together. I don't recall anhthing about the pulse air gap in the repair manual...or I possibly may have missed it. May sound like a silly question, but the flywheel indicator is the raised metal on the outside of the flywheel, and the pulse generator is the little black looking box?

[yaegerb]

Ok, no, I did not do this when I put it back together. I don't recall anhthing about the pulse air gap in the repair manual...or I possibly may have missed it. May sound like a silly question, but the flywheel indicator is the raised metal on the outside of the flywheel, and the pulse generator is the little black looking box?

I don't believe the pulse air gap is mentioned in the manual. Yes, the flywheel indicator is the raised metal hump on the flywheel and the pulse generator is the black box with a small circular magnet on the side facing the flywheel.

[rmcollector]

I don't believe the pulse air gap is mentioned in the manual. Yes, the flywheel indicator is the raised metal hump on the flywheel and the pulse generator is the black box with a small circular magnet on the side facing the flywheel.

Ok will take a look at both of these this weekend. Was going to order the Keihin 34mm pj carb, $170-$180 sound about right?

[rmcollector]

Got the new carb in today and she fired right up after a few kicks! Rode her around for about 30 min or so and runs great. Haven't seen no coolant loss that I mentioned in the first post, I will just have to keep an eye out and go from there if something comes up.

I appreciate everyone's help, especially yaegerb. Thanks for keeping in touch and mentioning that woodruff key. Big help for sure.

[yaegerb]

Got the new carb in today and she fired right up after a few kicks! Rode her around for about 30 min or so and runs great. Haven't seen no coolant loss that I mentioned in the first post, I will just have to keep an eye out and go from there if something comes up.

I appreciate everyone's help, especially yaegerb. Thanks for keeping in touch and mentioning that woodruff key. Big help for sure.

No worries man, glad to hear she is running well.