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New Member with An MC18...wait.....no...an MC16...yes MC18


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Andy
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Fri May 13, 2022 10:07 pm » Post: #166 » Download Post

Is that how the crank stands now? It's in your possession, and has been returned in one piece? If so, the guy's BS'ing you! It's impossible to tell if it's totalled until it's completely stripped to its component parts, and they're all inspected and measured.

I expect T2R have a good stash of use '88 crank parts, because they have easy access to Yahoo! Auctions, where they come up quite a lot. However, be prepared to pay for the pleasure if they rebuild it/supply spare parts. They have a great reputation though, and superb resources, and if I didn't have other options, I wouldn't think twice about sending Matsumoto-san and the guys my stuff.

I know Performance Engineering don't have many, if any used 1988 spare parts, as the (very) few that weren't rebuildable while I was there were sent back to their respective owners. So if Steve strips your crank and finds the big ends or rods are indeed shot, you'll likely either need to source spares yourself, or write it off (for the cost of the inspection fee, which used to be, and I think still is, £25).

Both T2R and PE will return a duff crank in its component parts only, for the cost of the assessment fee and return postage. You will not get it back all pressed back together. This is for three reasons, the first is it's pointless pressing an unserviceable crank back together (it would cost £300+ in labour alone), second, the outer bearings are destroyed removing them, and third, to prevent any unscrupulous shylocks from trying to pass off a crank as "it came out of a running bike" to some unsuspecting buyer. (Seen it happen!)

In respect of the above, PE is significantly cheaper than T2R, but T2R has the advantage of probably having spares if required.
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Hudtm60
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Mon Dec 02, 2024 5:36 am » Post: #167 » Download Post

OK...where was I...I know it's been a few years but I'm intending to start rebuilding the engine and wondering if this reply is adding onto my thread or is this completely new....plus I have to re-learn how to post pics within the post....clearly I've done it before but I have no recollection how! Not a good sign!

But wait....this is how you do it...


I am still bewildered with the difference of these 2 ports....one is completely rectangular the other...not at all...this pic doesn't show the difference as well....will take another tomorrow..

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Rothmans_SPud
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Mon Dec 02, 2024 9:47 am » Post: #168 » Download Post

Hey thought we’d lost you - good to have you back !

Ref the ports above - I wondered them same thing but was too embarrassed to ask just encase it was the most stupid question in the world to ask
I put it down to the fact one barrel is closer to the carbs than the other (not parallel twins)

Pulling a chair for build updates and pics
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Hudtm60
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Tue Dec 03, 2024 2:07 am » Post: #169 » Download Post

Glad to be back! Sorry- nothing exciting to report today and going to be out of town for work so there will not be much progress other than the continual bewilderment over the difference in port shape and if I should do anything about it.

this one is good. No excess metal and as rectangular as you can get


This one def deserves a 'what the?" how did it leave the factory like this?


view from the other side...


the good one from the other side...


Should I shave away all the excess? Well...I'm not experienced in any kind of metal removal from engines so I think not and I'll simply rely on...it's as God (Honda) made it and so it should stay.
I think.

Hopefully I will make more progress the weekend after next....however if I get a chance this week I will finally unpack and inspect the crank Chris Applebee reconditioned. The only person in the world who said he could do it!
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Hudtm60
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Thu Dec 05, 2024 3:32 pm » Post: #170 » Download Post

Unboxed the crank last night. Work was done by Chris Applebee Engineering.

I didn't get much detail on what he did just "JOB NO 9415 NSR 250 CRANKSHAFT RECON £338." Looks wonderful to me.














Last edited by Hudtm60 on Thu Dec 05, 2024 3:37 pm; edited 1 time in total
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Rothmans_SPud
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Thu Dec 05, 2024 3:33 pm » Post: #171 » Download Post

Dude Your posting porn again Laughing

Wasn’t aware that Applebee’s engineering in Essex did crank rebuilds
Thought it was only Steve at GT engineering who had the know how and parts to do it

Fair play to you for tracking that one down - especially from Nashville !


Out of interest what sort of import tax do you guys pay - it’s 20% here plus an £8 admin fee and it soon mounts up 🤬
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ericandchi
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Fri Dec 06, 2024 1:40 pm » Post: #172 » Download Post

Regarding your cases, they can always benefit from a little cleanup of the casting marks. Just use a rotary tool with a sanding drum small enough to get in there and smooth all the rough edges. Don't try to take that stuff off on the one side that looks funny, just get the rough edges smooth. Porting is not about making the holes bigger, it's about helping the air/fuel mixture flow quicker through the system. Those rough casting spots only slow the air down so taking them off is ok. Don't get too crazy.

Once your done clean them, then clean them a few more times. The best method is in a big sink with hot water and dawn dish soap. Scrub every surface and use little bottle brushes to get into all the journals. The vapor blasting that was done left residual material that you gotta clean out, plus any bits left behind if you do clean up the ports. If you did not remove the upper and lower needle bearings where the clutch throw arm passes through, you gotta pay extra attention in there. Spray a fair amount of carb cleaner in there. Once your done cleaning put a little 2T oil on them with a q-tip.
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Hudtm60
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Fri Dec 06, 2024 4:41 pm » Post: #173 » Download Post

Very much appreciate this info ericandchi. I'm looking forward to getting at it...and getting it right...from the start.

some nice work done here on the oft cracked exhaust bridge....


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Turn 1

 
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Fri Dec 06, 2024 8:37 pm » Post: #174 » Download Post

I am surprised no one has responded to your concern about the odd shape in the intake passage. I had the same concern when I rebuilt my motor many years ago and was told this. A two stroke engine breathes by compressing the fuel/air mixture in the crankcase and then transferring it to the combustion chamber. Those odd lumps are there to make the case volume the same in both sides so equal amounts of fuel/air mixture gets to both cylinders.
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Hudtm60
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Fri Dec 06, 2024 8:59 pm » Post: #175 » Download Post

Thank you Turn 1. I very much like having confirmation that what looks like an oversight is part of Honda's genius and I'm glad I haven't touched the port...tempted to smooth the edges a it per ericandchi....but we'll see.
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Hudtm60
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Sat Dec 07, 2024 2:07 am » Post: #176 » Download Post

Yes...it was PJME who recommended Applebee. Over here in the US, they said Ed Toomey was the man so I gave him a shot, but after he had it for 338 days with no progress (he was too busy and a few suppliers never made good on parts he was promised) I put him out of his misery asked for it back and as soon as I got it I sent it over to Chris...and I had it back within the month...wasn't the most straightforward repair I've ever experienced, but it looks like it was worth waiting for..install and running it will tell!...as to import tax I don't recall paying anything. Applebees sent me a bill, I wired him the money and it arrived a couple of weeks later.




Wayne_Gardner wrote:Dude Your posting porn again Laughing

Wasn’t aware that Applebee’s engineering in Essex did crank rebuilds
Thought it was only Steve at GT engineering who had the know how and parts to do it

Fair play to you for tracking that one down - especially from Nashville !


Out of interest what sort of import tax do you guys pay - it’s 20% here plus an £8 admin fee and it soon mounts up 🤬

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Andy
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Sat Dec 07, 2024 7:42 pm » Post: #177 » Download Post

1988 RS250R NF5B inlet...







Suitable for in excess of 70rwhp. 😉

You can just debur the sharp edges a little, but I wouldn't worry about it for 95% of use cases.
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Hudtm60
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Thu Dec 12, 2024 6:23 am » Post: #178 » Download Post

Thank you for posting! Looks almost exactly the same.

Snuck into the garage only to mimic the first rebuild thread photo....hopefully more progress this weekend.


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Hudtm60
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Sat Dec 14, 2024 4:36 pm » Post: #179 » Download Post

it's beginning to feel a lot like Christmas...I had an evening to myself so I decided to drag everything out to see what I have ready and what's missing. I surprised myself to find I'm pretty close to having it all...

The experienced of you will see duplicates..having grown up skint most of the time I never think I've got enough of anything...so at some point I bought a box of NSR fasteners from Australia...just to make sure I had enough of everyhing.


Repaired and plated- top end looking good....


All things brakey....still work to do on the rear brake...


Much improved...


Transmission was sent to R&D to be checked for integrity and then to have the dogs undercut. Some say....Smile...once you've experienced a race cut transmission...everything is secondary....well....it's not that dramatic....at least on the street......but it's nice.


I'm quite excited to have a pro engine stand...it came all the way from Thailand. Tyga. Going to wash these bits in Dawn later today.


My New Bits box...has lovely things like a new shock- original was set up for the young and sprightly local 90lb/6.5 stones individuals...if I remember correctly this YSS shock will be more suited for my 165lb frame...also in there braided brakes lines from HEL, gaskets, new switchgear, new cables, clutch plates, seat lock, it's very exciting.


Box of new cooling bits including hoses....I'm second guessing the colour now..wish I'd done black...and a new impeller.


A lot of the electronics and a better case cover...


Need to add these bits...


To these...


this pic will hopefully help...



anyway...time to get to work...
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Hudtm60
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Sun Dec 15, 2024 7:07 am » Post: #180 » Download Post

Day spent in with an undercurrent of panic as parts were thought lost forever but were later found in a some very organized drawer or plastic bag. wouldn't like to/be able to do this for a living. yet.

per the advice of you experts on here (ericandchi)....it's all about the flow...decided to get rid of these rough edges instead of removing all of the odd shaped material because Turn 1 reminded us that "A two stroke engine breathes by compressing the fuel/air mixture in the crankcase and then transferring it to the combustion chamber. Those odd lumps are there to make the case volume the same in both sides so equal amounts of fuel/air mixture gets to both cylinders."


which took a few seconds....hard to tell but, yes, smoother...


cleaned up the stud threads...


and...very carefully and slowly...ran the threads in the cases with a bit of tap oil...and blew them out


and they got the bath I had promised (as prescribed by ericandchi)


made sure all the oil ways were clean..


paid particular attention to clutch actuator and shifter bearings...they did indeed feel a little gritty...later some aersol electronic clearer and compressed air had them spinning gaily...


first install was the oil screen....cleaned bolts and threads...applied a liitle Loctite and that was that.


took a closer look at the shifter rod which when dismantled had this going on...


looked up to see if I could get a new 24610-KV3-000....ha-ha. no chance...that being the case it doesn't look so bad. Smile so carefull filing should get those straight to mate with the lever.


only other thing I did was install the kickstart piece...



Last edited by Hudtm60 on Sun Dec 15, 2024 7:32 pm; edited 3 times in total
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