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honda cr450 81 rebuild

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all I hear was these bikes are crap. they just dont get enough love so I'm going to change that!

I used to race one of these 'back in the day' but I dont mean 1980's . I mean early 2000's and back then I was up against the new breed of 450 4 strokes, odd 500 smoker and plenty of husabergs etc.. 

it was used for sand /beach racing events and wow was it fun. 

never won a race on it but had a few holeshots and top 5 results. 

I do however remember the suspension tying itself in knots flat out in 4th and having the high side of my life! turns out wet sand isn't quite as soft as youd hope lol

after retiring it from racing I used it to commute 15 miles per day to work , every day.... 

this is what I never understood about reviews of the cr450.  people say unreliable bag of bolts . I say reliable,  fast and bouncy. 

I normally ride a husqvarna 300  but I've always fancied another so when one came up for sale recently in bits I jumped on it.

its 90 percent complete.  no cracked frame or swingarm.  engine complete but frozen from being sat.

the plan is ...

rebuild the motor with some port work and update the chassis. I could do a normal restoration but I want to race it in hill climb events, sandracing and some H+H events . non classic events.  against new stuff just like I did back in the day.  not expecting to come away with trophies but I expect to have a good laugh trying.

 

 

 

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to help with the build I have a partially complete kxf250 sat there. it's going to give up its talon wheels, full front end , rear master cylinder,  have a husaberg rear caliper (brakes on the wrong side).

after some measurements the kxf front end is ideal. the offset on the yokes is correct, for length correct and will clear the tank nicely 

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off with the yokes. pressed out the stem. made a interference fit spacer so the cr450 stem fits the kxf yokes.

all looks good.

this is only temporary as the stem on the cr450 is steel so I'll be making a aluminium one to lose some weight.

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notice the 480 tank I'm going to try. this is so I can run the 480 seat although I believe you can buy a safety seat for the 450 to use the original tank? I haven't seemed to find one new though, only pics of used ones

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rear wheel spindle size is 20mm . the kxf is 25mm so I'll machine some captive spacers for the wheel.

the husaberg rear caliper is also 25mm so will take a nice captive spacer too.

theres quite a lot of work on the rear end to do. I almost kept the rear end but the torque arm and brake cable would be in the way for log hoppings and would soon get mullered. 

looking for a ohlins rear shock if anyone has one for sale.

footpegs have been taken care off. had some aluminium one from a yzf I believe.  they need literally 1 mm shaving off to fit. angle is correct too.

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That's great!  The 81 CR's are some of the best looking bikes in my opinion. I have two 81 CR 125's.  One is an all original bike (except the decals) and the other is a parts bike. Lots of fun to ride if you learn how to use the clutch to keep the revs up it tight spaces.  Keep us posted on your progress.

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worked on the engine tonight. 

unfortunately the crank had been left in 3 inches of water ffs.

piston was seized to the bore so took some serious persuasion to come apart as did the crank. safe to say a rod kit will be needed

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Good luck with it .  Post pic's when possible ,   sounds like fun...

Edited by bweighmaster
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thanks for the encouraging words guys. I do have a few questions I'm hoping members can help with.

480 and 450 have the same stroke. are the con rods the same?

rear engine mount on the 83 480 looks to be aluminium whilst to 450 is steel. would be nice to swap if it's the same?

also does the 5 speed cr480 gearbox swap over? 

any ideas ?

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thanks pygmy.  just spoke to him this morning and must say hes very helpful and has amazing experience with these machines. 

crank is going to him as the 480 rod will work but is wider so needs cut out on the inner webs to give clearance 

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Great to hear! Unless you already have a piston, you may want to ask him about what to use. I don't see where anyone  makes them.   Ebay is a great resource for used and NOS parts btw. 

Keep us posted on your build.

 

Here is a pic of my 81 CR125.DSC_0004.JPG.2e139a76a2ab42dc1f71fd4bd317adcd.JPG.

Edited by Pygmy Warrior
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wow now that is a beauty. 

apparently the liner is so thick in these i can bore it to 89mm to use the cr500 /480 pistons as long as they dont have the bridge cooling holes for the cr500.

 

its basically going to be a 480 but says 450 on the seat lol.... cheater bike!

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bearings and seals removed from crack cases today. 

managed to get full bearing and seal kit from my local supplier for £72.

only 1 they didnt have was a gearbox bearing which is £20 . still very cheap job though.

theres been some rub marks from a chain at some point. I remember my last one I had the same issue with heavy duty chains or trying to fit 14t front sprockets.  lesson learned.  narrow D.I.D o ring chain required for peace of mind and 13t front maximum. 

 

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case all welded up.

just needs a little more prep work before being sent for powdercoating

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I case you need it...I had this guy in Canada reproduce the rear shock decal for the 81 CR's.  He did a great job.  He has lots other decals too. 

http://www.bdesigns.ca/80s_Honda.htm

CR Models - Monoshock Rear Suspension Caution decal. Brushed aluminum backing. $10.82 plus S&H. Part # HON-80CRM-MSC-01

 

 

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On 10/1/2019 at 7:57 AM, Pygmy Warrior said:

Great to hear! Unless you already have a piston, you may want to ask him about what to use. I don't see where anyone  makes them.   Ebay is a great resource for used and NOS parts btw. 

Keep us posted on your build.

 

Here is a pic of my 81 CR125.DSC_0004.JPG.2e139a76a2ab42dc1f71fd4bd317adcd.JPG.

Rare hang nail front number plate...

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On 9/30/2019 at 6:01 PM, sandking11 said:

thanks for the encouraging words guys. I do have a few questions I'm hoping members can help with.

480 and 450 have the same stroke. are the con rods the same?

rear engine mount on the 83 480 looks to be aluminium whilst to 450 is steel. would be nice to swap if it's the same?

also does the 5 speed cr480 gearbox swap over? 

any ideas ?That bike you have there my friend is known as the last Elsinore. Roger "D" came in and changed everything to make the CR's bad to the bone. Elsinore bikes were already sweet rides but he made them much better. As for swapping parts on those scoots, you could try, but I would advise against it. Check on Ebay for the correct 450 parts, if you are luck you might find a complete running 450 motor. You could put a 82 up 480 engine in that frame, but it might require some fabbing. Good luck brudda, let us know how it works out.....cr-450-r_1981_1.jpg.18aa7be892f522bfb3796185004a3b2d.jpg

 

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a update is well overdue on this one.

parts have been arriving finally as most have been ordered from US. also the crank and cylinder are now ready.

finished the right rear wheel spacer and have the left to go.

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