1987 Honda CR250 Project

mosslander
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5/30/2011 12:24pm
nine1seven wrote:
I have been slacking on posting about this project.... There are a lot of parts that are sold out and not available any longer so I've...
I have been slacking on posting about this project....

There are a lot of parts that are sold out and not available any longer so I've been scouring the earth looking for NOS parts.

I made some progress on the engine. The main problem was the water pump was leaking out the weep hole. I suspected the right side case would be corroded but wow...Here is how it looked when I started taking it apart.

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I am going for a total rebuild on this motor. I split the cases and inspected everything. Alhough this bike would run when I got it, the cylinder had some scratches and scoring, probably from getting hot due to the plugged radiators and corroded water pump. Also, the clutch plates are completely worn out.

I sent the cylinder to US Chrome for re-plating since new cylinders are no longer available. You have to remove all the fittings, studs and power valve seats, etc before they will accept it. The cylinder head and base studs were frozen. I had a hard time getting them out with out breaking them. I was happy when I got the cylinder back, the bore looks like brand new.

After getting the cylinder I mocked the engine back together and media blasted it. I then took it back apart and painted each piece. I was able to get the engine data tag off and back on without damaging it. Here is what it looks like after paint:

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Have you modyfied the spring location for the powervalve spring and is it easy to shanges spring after hop up
jtracing6
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Dundalk IE
5/30/2011 1:44pm Edited Date/Time 5/30/2011 1:46pm
Hi,
Love the project. I wish I'd done a story with pictures when I built my 1986 CR250 David Bailey replica.
How did you get the engine and frame number tags off clean? I always manage to wreck mine!
Glad you splashed out on the HRC clutch and ignition covers, they make the engine. Don't forget to plate or replace the engine bolts with silver (or titanium!).
Great job.
Keith
Pat327
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5/31/2011 7:35pm Edited Date/Time 5/31/2011 7:38pm
How did you remove and replace the frame and engine tags? What kind of paint did you use on the engine?

Looks really nice!
mosslander
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6/1/2011 10:48am
Pat327 wrote:
How did you remove and replace the frame and engine tags? What kind of paint did you use on the engine?

Looks really nice!
At stearingheads inside you feel the sharp end of the nail that holds the tagplate and simply press them out ,

at the engine i will think you need to heat up inside case and use wood chessle or a knife to bend the nail out I guess

The Shop

nine1seven
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Magnolia, TX US
6/2/2011 6:44am
Thanks guys! Mosslander is right on about the frame data tag. You can tap them out a bit from the inside of the head tube. The Engine tag requires the best small pliers you can find with the sharpest edge to grasp the rounded edge of the tacks. Then just turn counter clockwise and pull as they are threaded. I reused the fasteners again.

I used PJ1 satin black paint. It is high temp, a pretty close match to the original and seems pretty tough. I thought about getting dogger315 to powder coat the clutch and ignition covers and still may. He has all these Honda colors matched in powder. You could probably do the whole engine but I worry that powder coat would insulate and make the engine run hot. I don't know for sure about that.

Keith, I wish you would have taken some progress pics of your Bailey replica too! Amazing attention to detail! You could really fool some folks into thinking that is the real thing with the rear disc. Did you go all out with the Ti on yours? Did you ever get any more of those fork/disk guards?

What do you guys think I should do about the rear wheel? I am leaning towards a 19" like Vino did with his 87, but maybe I should stay with an 18" since that is what the factory bikes had in 87? I've got matching Excel gold 21/19" rims/spokes ready but I could re-anodize a set of 21/18" stockers and stick with the old school 18". Bothers me that the 18" would be heavier.
jtracing6
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Dundalk IE
6/2/2011 1:39pm
Hi Nine One Seven (is that your postcode or after my favourite race car-Porsche?)
Yes I nearly fooled a couple of people at Farleigh castle last year. One or two asked if it was new!
Stay with the 18" rear the tyres look better with the higher side wall. Depends if you want to race it I guess. Problem is getting the light gold rims. On my 1986 CR125 I was lucky and found 2 NOS rims. On my CR250 DB I used SM Pro rims from a company in the UK,a little darker but not much choice.
I'm looking at shelling out for some Ti bolts but it gets a bit frightening when I add them all up.
Yes I have some sets of Fork, Disc and Reservoir guards in my garage. Let me know if you're interested.
Check out my Facebook photo page for more pictures of my DB replica. Link below.

http://www.facebook.com/media/set/?set=a.197223590313809.37864.10000078…

Keep it coming I love these articles. I'm doing one for my CR250 1996 McGrath but there seems to be a lot of MC reps at the mo'.
6/2/2011 1:57pm
You can use a water pump cover from a 1989 CR250, it is made of aluminum and it bolts right up.

Honda no longer carries the 1987 water pump cover that is made of magnesium.
CamP
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Colleyville, TX US
6/2/2011 7:07pm
koolstrike wrote:
You can use a water pump cover from a 1989 CR250, it is made of aluminum and it bolts right up. Honda no longer carries the...
You can use a water pump cover from a 1989 CR250, it is made of aluminum and it bolts right up.

Honda no longer carries the 1987 water pump cover that is made of magnesium.
The 90-91 cover also fits and it's about $70 cheaper than the '89 cover.
mosslander
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6/6/2011 4:13pm
Buy one 87 and one 86 today at the same time for 400$ and the 87 had the Öhlins shock but none of the bike were complete and I will pick them up next week.
jtracing6
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Dundalk IE
6/6/2011 10:58pm
Mosslander,
What a bargain! I'm going to the Latvia MXGP, are you going?
I have a lot of 86 CR little bits if you need anything let me know.
nine1seven
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Magnolia, TX US
6/8/2011 1:53pm
The motor is going together with all new OEM seals, bearings, gaskets, clutch plates, clutch springs, right side case, water pump impeller, base studs, head studs, dowells, piston, rings, circlips, wrist pin and bearing and so on.

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The right side case is the 89 version. I lucked out and found an original 87 right side case that is sand cast magnesium and planned on using that one until I found out how much they are worth. I decided to use the 89 aluminum one since it does fit. Shown below is the old corroded 87 case and the new 89 case installed (note the inspection cover)

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There is a caveat to using the 89 though. The HPP Power valve is notoriously hard to adjust and maintain. I imagine there are a lot of these CR's around that run poorly because the power valves are not adjusted correctly. When you use an 89 right side case with the 87 water pump and center cases you lose the ability to disengage the power valve governor mechanism externally (which is why there is a access cap on the 89 and a threaded hole on the 87). The only way to reinstall the cylinder with the power valve actuation arm is to remove the right side case, drop the cylinder into place and match up the power valve actuator arm and then reinstall the right side case. I spent many hours getting the power valve adjusted correctly and then had to remove the right side case to install the cylinder because of this issue.

Here is a shot of the new bore:

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Fatbatster
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Cordova, TN US
6/8/2011 2:07pm
Instead of removing the side cover in order to install the cylinder, why can't you just leave the side cover installed? Then, when you go to install the cylinder, hold the powervalves closed as you drop the cylinder onto the cases. That is how I did it before and after the "89 model side case upgrade".
nine1seven
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Magnolia, TX US
6/8/2011 2:25pm
They should be closed anyway. If you have to hold them closed there is something wrong. Chances are the shaft splines are not lined up right when you dropped them into the cylinder which would cause them to not close completely.
Fatbatster
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Cordova, TN US
6/8/2011 3:28pm
I am going to have to respectfully disagree. When the cylinder is not on the engine, the valves will naturally be in the open position. On the 1986 and 1987 CR250, the only thing holding the power valves closed is the governor shaft that comes up from the water pump area. If you remove the cylinder from the engine cases, the power valves should snap open immediately. Basically, on these models, the governor shaft is the only thing that closes the power valves. Conversley, the powervalve springs in the top of the cylinder are the only things that open the valves. There is no mechanical connection between the governor shaft and the powervalve rack that can "pull" the power valves open. Again, this is in reference to the 1986 and 1987 models only.
nine1seven
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6/8/2011 4:00pm
Yes, that is true when the cylinder is on they should be closed. The pressure holding them closed by the governor shaft should not allow you to drop the cylinder in place, which is why there is a procedure for disengaging the governor. If the powervalve rack is correctly aligned I don't think it is possible to do it without relieving the pressure on the governor shaft.

However you are able to do it on yours, great, but at the end of the day, make sure the e-clips bottom out on the valve guides and when you manually open them they measure 20.5 - 21mm open.
nine1seven
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7/9/2011 9:36pm
Finally got to spend some time on the project this weekend. The engine is all finished.

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In the Frame:

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I found a new OEM silencer on Ebay. I also bought an 87 CR125 top clamp which is solid mounted whereas the 250 version is rubber mounted. It is lighter and best of all, it moves the bars up and forward so this old relic won't feel so goofy with the bars way back in your lap.

Next on the agenda is to start building some wheels.
jtracing6
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7/9/2011 11:15pm Edited Date/Time 7/9/2011 11:16pm
Looking good ! (not you, the bike I mean!).
jps
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FR
7/10/2011 12:59am
jtracing6 wrote:
Looking good ! (not you, the bike I mean!).
Wink
Great job, nice bike !...

jps
tydog
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Monticello, GA US
8/3/2011 4:08pm
vino3 wrote:
Elkinhammer, Bitchen bike! Nice 125. Smart move on the fork combination. As long as the bottoming cones fit in the 83 lower sliders. It sounds like...
Elkinhammer,

Bitchen bike! Nice 125. Smart move on the fork combination. As long as the bottoming cones fit in the 83 lower sliders. It sounds like you already figured that out.

Why did you go with yellow backgrounds with your 125?
I hate to be a "Johnny come lately" on this thread, BUT the bottoming cones of the 87 and 83 are different and in a respect, that in my opinion as a machinist, really should be addressed. I am currently working on a project using the 87 internals in 83 sliders and I am at the assembly stage. The o.d. of the bottoming cones of the 87 are .042" larger than the spotface that is in the bottom of the 83 sliders that accepts this o.d. The issues that this would eventually create is pretty obvious as are the two ways that this can be corrected by a competent machine shop. If anyone really wants the gory details feel free to contact me and I will tell you how I am going to fix the ones that I have.
Killer resto's by the way gentlemen and nice attention to detail!!!!!!!!!!!!!!!!!!
nine1seven
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Magnolia, TX US
8/19/2011 9:42am Edited Date/Time 8/19/2011 9:48am
I finished building my wheels:

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I'm saving quite a bit of weight by using a newer rear hub and axle, aluminum axle carriers, spoke nipples and bead lock. I also turned the hubs down on a lathe and removed the casting marks then painted them satin black. I had to machine the wheel spacers and the axle carriers.

I took the following picture before I machined the carriers. Stock 87 on left:

Photobucket

I used a 19" rim and I'll use the lightest tires/tubes I can find. I weighed several models and the MX31 is the lightest around. I'm going to go with the next lightest, the Dunlop K952 because it looks just like the 752 from back in the day and it is available in 110/90/19 size whereas the MX31 is only available in 110/80/19. I saved nearly three pounds of unsprung weight from the rear wheel alone.
1
CamP
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8/19/2011 11:28am
Sweet!
sfairbro
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Pittsford, NY US
8/29/2011 1:10pm
Looking awesome!!!!!!!!!!! Can't wait to see finished product.
DynoDan22
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Victorville, CA US
9/7/2011 8:40pm
nine1seven,

Great job so far! I am just starting my own '87 CR250 restoration and your posts have been a huge help. I have one of Mickey Dymond's '87 250s with very low hours that I am begining to restore. I have a question on the right side case swap ('87 to '89). Does this alter the powervalve preload on the spring when switching to the '89" it appears the '89 left side case would lessen the preload as the spring boss is slightly deeper? I know the difference in spring tension would change the power characteristics. Thanks in advance!
nine1seven
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Magnolia, TX US
9/8/2011 7:56am
Thanks guys! DynoDan, what's the story with Dymond's old bike? I'd like to see that project come together for sure.

I'm with you on the spring preload as there isn't any way of adjusting it when you swap to the 89' version. I think we should remedy that. The 87 version uses a set screw to compress the spring retainer and spring. The 89 just has a cap so we could tap it and add a set screw or machine a aluminum cap that incorporates that. I will say that there is a lot of pressure on the power valve as mine is now. I will test it out when I finish and maybe get into that if you haven't already worked something out for us!

My 87 is a rolling chassis now. I had to spring for new radiators from Myler's. I was concerned that I wouldn't be able to get all the cores cleared out in the old ones. These were a lot cheaper than OEM and they look like they could be works units with the shape and welds. They fit well except for how the hose outlets on the bottom are aligned. I had to twist on them to make them line up the same as the original radiators, luckily the spouts were really malleable and didn't break.

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Next I am going to build the forks. I am going to Chromic Acid Anodize the lower sliders so they look like the works Mg units.
CamP
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9/8/2011 8:57am Edited Date/Time 9/8/2011 10:22am
I have two friends that vintage race an '87 and '88 with '91 clutch side covers. They haven't mentioned anything about how the powervalve spring preload affected the power, but I'll see them next weekend when our fall series starts and I'll ask them if they noticed any difference.
DynoDan22
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9/8/2011 9:29am
nine1seven: I bought Mickey's 250 second hand from Mickey's mechanic who had it in storage for years. I even have the pink slip with Mickey's name on itSmile I have two other "sacrificial" '87 250s with decent radiators. I can look at them and if you are interested let my know. I really just need to measure the spring preaload difference between the 87 and 89 and compare. I haven't torn into the other 250 with the O.G. right side case on it. Were you able to find oem side plates and rad shouds? I am still searching....lol I dod have a new oem seat in box that came with Mickey's bike also. The bike also has factory wider pegs (nice pieces, not hacked together weld on units, and a factory pipe. I really got lucky! Thanks so much for the help!
9/9/2011 5:47pm
DynoDan22 wrote:
nine1seven, Great job so far! I am just starting my own '87 CR250 restoration and your posts have been a huge help. I have one of...
nine1seven,

Great job so far! I am just starting my own '87 CR250 restoration and your posts have been a huge help. I have one of Mickey Dymond's '87 250s with very low hours that I am begining to restore. I have a question on the right side case swap ('87 to '89). Does this alter the powervalve preload on the spring when switching to the '89" it appears the '89 left side case would lessen the preload as the spring boss is slightly deeper? I know the difference in spring tension would change the power characteristics. Thanks in advance!
I have a '89 water pump cover on my '86 CR. No change in power characteristics. Bolt up and go!
mosslander
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Location
Travad SE
9/10/2011 3:32pm
DynoDan22 wrote:
nine1seven, Great job so far! I am just starting my own '87 CR250 restoration and your posts have been a huge help. I have one of...
nine1seven,

Great job so far! I am just starting my own '87 CR250 restoration and your posts have been a huge help. I have one of Mickey Dymond's '87 250s with very low hours that I am begining to restore. I have a question on the right side case swap ('87 to '89). Does this alter the powervalve preload on the spring when switching to the '89" it appears the '89 left side case would lessen the preload as the spring boss is slightly deeper? I know the difference in spring tension would change the power characteristics. Thanks in advance!
koolstrike wrote:
I have a '89 water pump cover on my '86 CR. No change in power characteristics. Bolt up and go!
X2 about the cover on my 86 CR
MaxPower
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8/15/2006
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NJ US
9/12/2011 3:57am
nine1seven wrote:
I finished building my wheels: I'm saving quite a bit of weight by using a newer rear hub and axle, aluminum axle carriers, spoke nipples and...
I finished building my wheels:

Photobucket

I'm saving quite a bit of weight by using a newer rear hub and axle, aluminum axle carriers, spoke nipples and bead lock. I also turned the hubs down on a lathe and removed the casting marks then painted them satin black. I had to machine the wheel spacers and the axle carriers.

I took the following picture before I machined the carriers. Stock 87 on left:

Photobucket

I used a 19" rim and I'll use the lightest tires/tubes I can find. I weighed several models and the MX31 is the lightest around. I'm going to go with the next lightest, the Dunlop K952 because it looks just like the 752 from back in the day and it is available in 110/90/19 size whereas the MX31 is only available in 110/80/19. I saved nearly three pounds of unsprung weight from the rear wheel alone.
I had needed the rear wheel from my YZ125 on my WR450 because it was flat.
I couldnt believe how much of a difference I noticed with the lighter wheel. I actually weighed it after I got home because it was such an improvement. I was shocked how much lighter it was so I weighed it (3 lbs)

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