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'84 XL250R - Engine Swaps?

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What I have is a 1984 XL250R with an unknown year XR rear-end and maybe the same, single carb engine. Number on engine is ME06E-5204756. Very hacked-up airbox mod that I was thinking about changing. But that was then...

Last saturday I was in a hurry to get into town & forgot to check the oil.:smirk: 5 miles down the road, started losing power so I figure the gas needs to be switched to reserve, nope! Piston seized, two or three breaking sounding noises - maybe clutch rattle? - rear tire locked-up and I went sliding for a couple seconds while in 5th gear doing 50 before pulling the clutch in.

Today, kickstart just stops solid. I tried rocking the bike backwards in 6th gear, still shifts ok, but no movement out of the crankshaft so I think the connecting rod is still in one piece. But the scary sounding noises and the thought of doing a major overhaul is making me think I'd rather just get a whole 'nother engine!

So what I'm wondering is, what options do I have? Like if I search ebay, there's a bunch of different engines, but what'll bolt-in? Upper bracket can be fabbed, but those two lower rear bolts would seem to be the critical factor.

I also just missed-out on a XT200 engine & complete electrics for $150 - would that have fit?

I heard a rumor I have to stick with RFVC engines. Because of bolt-up? Or just an electrical connector problem? By the way, that's what type is in the bike.

Eventually, I'll tear the engine apart if only to see what happened. But it might turn into a re-build. Any help is appreciated. Thanks.

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What I've managed to find while looking for any info on my engine:

1984 - XR250Re - 5001166~5004208

1985 - XR250Rf - 5100011~5200733

1986 - XR250Rg - 5200011~5200733

1987 - XR250Rh - 5300006~5301516

1988 - XR250Rj - 5400010~5401738

1989 - XR250Rk - 5500001~5500790

1990 - XR250Rl - 5600001~5602424

1991 - XR250Rm - 5700001~5703105

1992 - XR250Rn - 5800055~5802221

1993 - XR250Rp - 5900003~5902142

1994 - XR250Rr - 5000774~?

1995 - XR250Rs - 5050001~?

This was supposed to be the number ranges for the engine, but the number on mine falls in between 1986 & 1987, and the 'e' suffix on mine is listed here as a 1984 - so it looks like I'm not getting anywhere.

Does anyone know which years were double-carbed & which were single carbed?

Can I use any year rebuild kit?

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84-85 XL250R will swap for sure.

dont know about the later 86-89 XL250R models. I would assume they would, check the part numbers for the engine cases.

For the XR motors, again check the engine case part numbers

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All 84 up 250s are RFVC. Your lower end is probably good but the head and cam could be toast. All 250 heads are getting hard to find single or dual carb. An XT would be a Yamaha engine, An RFVC XL or XR200 could be installed but will be lacking on power. All XL250 dual carb motors will bolt in. Single carb XR or XL motors 86 to 94 can be used with a little modification. 95 on eill not work due to different mounting bolt arrangement. I have a good 84 bottom end if needed.

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84-85 XL250R will swap for sure.

dont know about the later 86-89 XL250R models. I would assume they would, check the part numbers for the engine cases.

For the XR motors, again check the engine case part numbers

I've been looking into rebuild kits today, and I noticed that for example a piston kit will be for '84~'85 or for '86~'04.

So what changed? I'm certain that all MEO6 engines will bolt-up the same to the frame, but internally could be any kind of changes.

Also, as my engine is a single-carb with the number on it's case being: MEO6E-5204756, I'm thinking it's going to be the newer era. Providing that someone didn't just go and put a single-carb upper-end onto a dual-carb lower....is that possible? I would rather hope not in my case!

So it looks like as far as rebuilding goes, I should go with any kits for '86 & up.

As far as checking engine-case part numbers, that sounds like a fascinating bit of research, but I don't have access to that info. One of the nice things about Yamaha is they let you cruise around all the parts diagrams on their website - but I've had a hard time doing that with Honda. Is this info archived here? I myself would put the time into uploading diagrams if I had any...

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At powersportsplus.com I dug up these part numbers for the crankcase halves:

1984

Right#11100-KK0-771 from engine serial #5008698, XR200R, XR250R. Right#11100-KK0-000 up to #5008697, XR200R, XR250R. Left#11200-KK0-000 XR200R, XR250R.

1985

Right#11100-KK0-771 XL250R A, XL250R AC, XR200R A, XR250R A. Right#11100-KK0-770 XR200R A, XR250R A. Right#11100-KK0-772 XL250R A, XL250R AC, XR200R A, XR250R A. Left#11200-KK0-770 XL250R A, XL250R AC, XR200R A, XR250R A.

1986

Right#11100-KT1-000 XR250R A. Left#11200-KT1-000 XR250R A.

1987

Right#11100-KT1-000 XR250R A. Left#11200-KT1-000 XR250R A.

1988

Right#11100-KT1-780 XR250R A. Left#11200-KZ1-670 XR250R A. Left#11200-KT1-780 XR250R A.

1989

Right#11100-KT1-780 XR250R A. Left#11200-KZ1-670 XR250R A. Left#11200-KT1-780 XR250R A.

1990

Right#11100-KZ1-671 XR250R A. Right#11100-KZ1-670 XR250R A. Left#11200-KZ1-670 XR250R A.

1991

Right#11100-KZ1-671 XR250L A, XR250L AC, XR250R A. Right #11100-KZ1-670 XR250L A, XR250L AC, XR250R A. Left#11200-KZ1-670 XR250L A, XR250L AC, XR250R A.

1992

Right#11100-KZ1-671 XR250L A, XR250L AC, XR250R A. Right#11100-KZ1-670 XR250L A, XR250L AC, XR250R A. Left #11200-KZ1-670 XR250L A, XR250L AC, XR250R A.

1993

Right#11100-KZ1-671 XR250L A, XR250L AC, XR250R A. Right#11100-KZ1-670 XR250L A, XR250L AC, XR250R A. Left #11200-KZ1-670 XR250L A, XR250L AC, XR250R A.

1994

Right#11100-KZ1-671 XR250L A, XR250L AC, XR250R A. Left#11200-KZ1-670 XR250L A, XR250L AC, XR250R A.

1995

Right#11100-KZ1-671 XR250L A, XR250L AC, XR250R A. Left#11200-KZ1-670 XR250L A, XR250L AC, XR250R A.

1996

Right#11100-KCE-670 XR250R A. Right#11100-KZ1-671 XR250L A, XR250L AC. Left#11200-KCE-670 XR250R A. Left#11200-KZ1-670 XR250L A, XR250L AC.

1997

Right#11100-KCE-670 XR250R A. Left#11200-KCE-670 XR250R A.

1998

Right#11100-KCE-670 XR250R A, XR250R AC. Left#11200-KCE-670 XR250R A, XR250R AC.

1999

Right#11100-KCE-670 XR250R A, XR250R AC. Left#11200-KCE-670 XR250R A, XR250R AC.

2000

Right#11100-KCE-670 XR250R A, XR250R AC. Left#11200-KCE-670 XR250R A, XR250R AC.

2001

Right#11100-KCE-670 XR250R A, XR250R AC. Left#11200-KCE-670 XR250R A, XR250R AC.

2002

Right#11100-KCE-670 XR250R A, XR250R AC. Left#11200-KCE-670 XR250R A, XR250R AC.

2003

Right#11100-KCE-670 XR250R A, XR250R AC. Left#11200-KCE-670 XR250R A, XR250R AC.

2004

Right#11100-KCE-670 XR250R A, XR250R A-A, XR250R A-B, XR250R AC, XR250R AC-A, XR250R AC-B. Left#11200-KCE-670 XR250R A, XR250R A-A, XR250R A-B, XR250R AC, XR250R AC-A, XR250R AC-B.

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All 84 up 250s are RFVC. Your lower end is probably good but the head and cam could be toast. All 250 heads are getting hard to find single or dual carb. An XT would be a Yamaha engine, An RFVC XL or XR200 could be installed but will be lacking on power. All XL250 dual carb motors will bolt in. Single carb XR or XL motors 86 to 94 can be used with a little modification. 95 on eill not work due to different mounting bolt arrangement. I have a good 84 bottom end if needed.

Yep, brain fart on the XT!

So you think my main bearings are ok? What about the upper end to the connecting rod?

And what sort of mods are needed on the '86~'94 motors? Just curious only, as I'm starting to lean more towards a rebuild.

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www.servicehonda.com

use the advanced parts search.

look up the model, year and then find the part. click the "WHERE USED" button

simple

That site doesn't work very well for me. Might be because I'm using Firefox? But the powersportsplus site has a interchange listing on individual part pages. For example, I was looking at an '85 shifter spindle, and it includes the '88, '89 & '90 NX250.

My local guru tells me I should expect the cam and followers to be shot. As soon as I get a workbench setup, I'll start tearing into the engine. I should've known when I just recently got this free travel trailer with lots of counter space, that I'd be using it to tear something apart!

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Yep, brain fart on the XT!

So you think my main bearings are ok? What about the upper end to the connecting rod?

And what sort of mods are needed on the '86~'94 motors? Just curious only, as I'm starting to lean more towards a rebuild.

The bottom ends hold up well on all XRs. As you were told the cam and rockers may very well be wasted. If you already have a single carb engine you won't need to change anything. The single carb air boot supposedly fits the dual carb airbox. Any stock or aftermarket 250 piston 84 on can be used in any 84-85 or 86-94 XL/XR250 engine. Even though the stroke is longer on 86 up XRs the rod is shorter and compression height adds up the same.

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The bottom ends hold up well on all XRs. As you were told the cam and rockers may very well be wasted. If you already have a single carb engine you won't need to change anything. The single carb air boot supposedly fits the dual carb airbox. Any stock or aftermarket 250 piston 84 on can be used in any 84-85 or 86-94 XL/XR250 engine. Even though the stroke is longer on 86 up XRs the rod is shorter and compression height adds up the same.

To be safe, I'll stick to the kits for '86 up engines. I'm seeing about the same price for either choice. And the guru says he might get me a dealer price on a kit, I just need to decide on what size. He also said that he's seen the timing chains break from a seized cam and the valves bent.

The hack-job on my airbox didn't include a single-carb air boot. I think they may have used something from an entirely different bike, as it runs straight out of the airbox without the nice gradual turn from the other side of the box. I was looking at a friends XR250 today and noticed his airboot is bolted into the box with a steel ring around the edge. It looks like it's the same size and shape as the front of my box. But I already made my mind up I'm getting a universal Uni filter and I'm only keeping the back half of the box for a mud shield, and for the battery holder.

I also noted that my friends XR has a engine number that's a bit higher than mine, and his bike is an '87. So I think I have either an '86 or '87.

If I can post some pics here, I'll document the carnage as I go. And I'm thinking about having an oil-pressure switch installed.

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You would be safe either way. If you look up the numbers you'll find many of the piston kits have the same part numbers for both early and late engines. I've measured the compression height of nearly all the pistons available and found them all within 1mm. Don't bother with the oil pressure switch or even flow meter. Oil pressure is nearly zero, not even enough to activate a low pressure light. Honda relies on low pressure-high volume lubrication.

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You would be safe either way. If you look up the numbers you'll find many of the piston kits have the same part numbers for both early and late engines. I've measured the compression height of nearly all the pistons available and found them all within 1mm. Don't bother with the oil pressure switch or even flow meter. Oil pressure is nearly zero, not even enough to activate a low pressure light. Honda relies on low pressure-high volume lubrication.

No pressure? That would've been funny! I wouldn't make it out the driveway! My mind just kept insisting, even with all those roller bearings - that something in there is a pressure-fed plain bearing. I never once thought they might've kept using the splash-lubed design for the piston. There's a oil spray aimed at the piston, right?

Checking the oil on this engine isn't a quick & casual thing. The o-ring on the filler always sticks to the engine case and I'm guaranteed to have oil on my hands.

That 1mm in compression height would be enough of a difference that I'd want to check into it more. Do you have any rod-stretch specs? Or at the least, the piston/valve clearance specs?

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Check the clutch pull on the engine end. That will be different between the 84-85 engines compared with 86-95.

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Yup the 84/85 have the clutch arm almost directly at the top of the cover while the 86 on are down toward the back. Just have to use the right cable and bracket with either.

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Sound like you have a 86 engine in a 84-85 chassis, I had an 84 engine in an 87 chassis. The 84-85 engine has a different bore/stroke than the 86-95 engine, but they have the same motor mounts. Best air filter is the stock air box, just use a 86-95 air boot, it will fit your air box.

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One of the things I did when I first got this bike was just for the fun of it, I installed a wideband O2 monitor. That's morphing into a mechanical gauge with a patentable technology I need to do something about. But along the way, I noticed that the mixture gets richer as the bike picks up speed, no matter what the engine is doing. I think it's the kludged airbox mod introducing a flow restriction right before the carb - thus increasing the vacuum which pulls fuel out of the bowl through the jets. This is why I want to ditch the entire airbox. Besides the snorkel on top, there's about three major changes in the flow-path before the carb intake. So I would like to have a universal style filter right at the carb so that the first major change in the flow-path is the slide. The bike has a supertrapp muffler that I had to dial-down to protect my ears. I think the exhaust is really out-flowing the intake at the moment. I'm eventually going to add a ring to the muffler so it blocks all the noise from going upwards, then shuffle the closed baffle back a couple positions. Now to get back onto this project before the rebuild kit for my friends outboard shows up!

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puzzled

OP asks about XL

everybody else talks about XR

?????????????????????????????????????????????

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puzzled

OP asks about XL

everybody else talks about XR

?????????????????????????????????????????????

Simple, same basic motor and frame. This is an XR forum. Honda probably sold 20 times more XRs than XLs therefore the knowledge base is far greater for the XR.

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Simple, same basic motor and frame.

same basic ... kinda sorta

XRs only had dual carbs for what? 2 years?

XL250s did as long as they were sold in the US,

basic same frame does not work with dual and single carb

there is that little issue of a shock being in the way e.g.

so I will stay puzzled

that you guys seem to not know the difference between XR-R and XR-L

or pre and post 97 XR250

but call XR and XL 'same'

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