'84 250R advice

[Helopilots]

237829

I just acquired this R and I'm open to any advice you guys may have. A few things I've notice as I crawl around this thing; when I rock the trike side to side there seems to be a bit of play in the rear axle bearing housing, it doesn't open up smoothly on the throttle through the gears, the idle adjustment screw has no effect on idling at all, the rear brake caliper is about to fall off and the master cylinder is cracked and warped, and the exhaust could probably be replaced.

Any advice on the carburetor or locating the mentioned parts would be appreciated. Any other advice you may have as far as care, maintenance, or tweaks...I'm all ears.

Thanks and I hope everyone has a great Christmas!!

Mike

[El Camexican]

My best guess on why your idle screw isn't having any effect is that you may have a plugged up pilot jet, or that someone put a screw in that's too short, or perhaps you've confused it with the air screw. The wrong throttle cable, or one that is adjusted too tight could also be a problem if it is holding the slider higher than the adjuster screw. Is it idling too high or too low? Too high could indicate an air leak. Suggest you pull the carb and make sure it's clean it up while you wait for the axle bearings to arrive. A leak down test would be a good plan as well. Why chase ghosts? Could save you a blown engine as well. Once you have the carb off the trike you'll be able to see if the screw is raising and lowering the slider properly.

[fabiodriven]

I know I had originally told you that you may want to keep the bike original based on how clean it looked, but now that you've said all that it changes things a bit.

If you need change out the exhaust, that's simple enough. Find a decent aftermarket setup and swap it out. If the bike isn't running smoothly then there is a good chance you'll have to dig into the carburetor. It could just be dirty, it could be worn out from age, or it could just need to be jetted. If you're going to replace the exhaust you will have to jet the carburetor anyways. I can help you cross that bridge when you get to it. It may behoove you to buy a nice brand new carburetor for the best running quality and performance. I had an 81 300R which is the exact same engine you have but with a Hondaline big bore 300cc jug. Big bores are great as well if you decide to go that route, but that's not my point. My point in bringing that up is that bike was the absolute smoothest running two stroke I have ever owned. Bottom to top the bike was always on the power and there was never any coughing, burbling, or ring-dinging, which means your bike can be that way as well once you get everything sorted out.

When you say there is play in the rear axle bearing housing, I'm assuming you mean between the axle and housing as opposed to the housing being loose in the swing arm, yes? If so, simply replace your rear axle bearings and seals. It's not very difficult. While you're there you can diagnose and correct the caliper problem.

Is your front master cylinder cracked and warped or are you talking about the plastic reservoir for the rear master? If the front master is messed up you can get a master cylinder from any dirt bike or quad to replace that. The rear reservoir I would imagine could be replaced by a reservoir for something else if you can't find the correct R reservoir.

[Helopilots]

My best guess on why your idle screw isn't having any effect is that you may have a plugged up pilot jet, or that someone put a screw in that's too short, or perhaps you've confused it with the air screw. The wrong throttle cable, or one that is adjusted too tight could also be a problem if it is holding the slider higher than the adjuster screw. Is it idling too high or too low? Too high could indicate an air leak. Suggest you pull the carb and make sure it's clean it up while you wait for the axle bearings to arrive. A leak down test would be a good plan as well. Why chase ghosts? Could save you a blown engine as well. Once you have the carb off the trike you'll be able to see if the screw is raising and lowering the slider properly.

It was idling too low. I tried adjusting the horizontal screw on the right side of the carb. The one that's slotted and knurled so that you can twist it with your fingers. After negative results, I just twisted the throttle cable in the housing at the handlebar and it fixed it. Maybe that was treating the symptom rather than the cause.

[Helopilots]

I know I had originally told you that you may want to keep the bike original based on how clean it looked, but now that you've said all that it changes things a bit.

If you need change out the exhaust, that's simple enough. Find a decent aftermarket setup and swap it out. If the bike isn't running smoothly then there is a good chance you'll have to dig into the carburetor. It could just be dirty, it could be worn out from age, or it could just need to be jetted. If you're going to replace the exhaust you will have to jet the carburetor anyways. I can help you cross that bridge when you get to it. It may behoove you to buy a nice brand new carburetor for the best running quality and performance. I had an 81 300R which is the exact same engine you have but with a Hondaline big bore 300cc jug. Big bores are great as well if you decide to go that route, but that's not my point. My point in bringing that up is that bike was the absolute smoothest running two stroke I have ever owned. Bottom to top the bike was always on the power and there was never any coughing, burbling, or ring-dinging, which means your bike can be that way as well once you get everything sorted out.

When you say there is play in the rear axle bearing housing, I'm assuming you mean between the axle and housing as opposed to the housing being loose in the swing arm, yes? If so, simply replace your rear axle bearings and seals. It's not very difficult. While you're there you can diagnose and correct the caliper problem.

Is your front master cylinder cracked and warped or are you talking about the plastic reservoir for the rear master? If the front master is messed up you can get a master cylinder from any dirt bike or quad to replace that. The rear reservoir I would imagine could be replaced by a reservoir for something else if you can't find the correct R reservoir.


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Yep, the exhaust can is not the stock version I think. It's not raggedy or anything, just not in great shape.

It's definitely not running as strong as it should. You're right. Maybe looking for a new carb would be best.

The rear axles where they meet the sprocket and the brake disk are teetering in the housing. No lateral play, but they have about a millimeter of top to bottom play.

The rear brake caliper is shot. It looks like it has a Wilwood caliper that's barely hanging on. The system is dry. Not sure if it even holds fluid. I would rather replace it than eff with fixing this one.

[fabiodriven]

Gotcha.

Well as Nico said you cannot rely on the cable to hold the idle because as you turn the steering it will throttle up the engine. Just the incorrect way to do it.

The only caliper you can use is the one for that bike. You *should* be able to rebuild the caliper you have. I'm fairly certain all the parts are available for that. If the hose is compromised you can have a nice braided one made for peanuts, just look on eBay. I think you can still get a master cylinder rebuild kit for those as well if it needs one. If you have to replace the rear master, I would venture to guess there is something you you could retrofit from a newer and more common bike.

If you can get your hands on a compression tester it would be nice to see how much compression you have. If you test it remember to hold the throttle wide open while kicking. Low compression doesn't always indicate a total rebuild. If you catch them in good time it's very easy to run a bottle hone through and replace just the rings.

[Helopilots]

Gotcha.

Well as Nico said you cannot rely on the cable to hold the idle because as you turn the steering it will throttle up the engine. Just the incorrect way to do it.

The only caliper you can use is the one for that bike. You *should* be able to rebuild the caliper you have. I'm fairly certain all the parts are available for that. If the hose is compromised you can have a nice braided one made for peanuts, just look on eBay. I think you can still get a master cylinder rebuild kit for those as well if it needs one. If you have to replace the rear master, I would venture to guess there is something you you could retrofit from a newer and more common bike.

If you can get your hands on a compression tester it would be nice to see how much compression you have. If you test it remember to hold the throttle wide open while kicking. Low compression doesn't always indicate a total rebuild. If you catch them in good time it's very easy to run a bottle hone through and replace just the rings.

I will have to work the carb issue, I guess. The caliper, I've been looking for one for about 10 minutes, no luck.

Compression check is a good idea. What's the range for a good test? The seller included a jug and head. Maybe they'll be of use sooner than later.

[fabiodriven]

http://m.ebay.com/itm/1982-1984-ATC250R-Rear-Brake-Caliper-Rebuild-Kit-ATC-250R-/291804743084?hash=item43f0eb05ac%3Ag%3ABGcAAOSwc1F XcYRZ&_trkparms=pageci%253A3677c1bb-c4c8-11e6-955a-0050568f3bb0%257Cparentrq%253A0fb8ce1f1590a7eb7938 5d66ffe91246%257Ciid%253A3

[Helopilots]

http://m.ebay.com/itm/1982-1984-ATC250R-Rear-Brake-Caliper-Rebuild-Kit-ATC-250R-/291804743084?hash=item43f0eb05ac%3Ag%3ABGcAAOSwc1F XcYRZ&_trkparms=pageci%253A3677c1bb-c4c8-11e6-955a-0050568f3bb0%257Cparentrq%253A0fb8ce1f1590a7eb7938 5d66ffe91246%257Ciid%253A3

Not sure a rebuild kit is what I need. I may need an entire caliper. This one has an aftermarket part to it and I don't know if the regulah kit will do the trick. Yeah, I need the plastic reservoir at the top as well. I'll snap a pic of it in the morning and attach.

[fabiodriven]

It may just have a parking brake block off plate, very common and irrelevant to rebuilding.

[Helopilots]

It may just have a parking brake block off plate, very common and irrelevant to rebuilding.

Ahhh. Possibility, as it has no parking brake cable! Good catch there, Fabio the Slayer!

[HondaRidr]

If I remember correctly some years kx85s and cr85 calipers work. You can also use the master cylinder off of a cr85 and enlarge the holes or something like that for it to bolt up. I have one on my 83 but it's been a few years since I did the swap. The info is on airfoolers.com but the site is down for a few weeks at the moment. I will try to check when it's up

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[atc300r]

The 83-85 200x and 81-84 250r front calipers will bolt right on. As well as 82-84 250r rear calipers. Plus what is posted above.You need new rear axle bearings as Fabio stated.When you change the rear axle bearings use a heat gun or propane torch to heat the bearing carrier up. Bearings come out much easyer and less chance of breaking bearing carrier