Nak mr-1 #4 gets new idler tire!

jayk

Super Member
I DID IT!! all by myself, too.
got tires and extra washers (just in case) for nakamichi mr-1 #4, opened machine up half an hour ago, got washer off, then lifted idler wheel right off.

pried old hard tire off wheel, put new one on, put assembly back on its holder, made little cut in washer to ease re-installation, used scotch tape to get washer back into position, secured wheel assembly from below with a screwdriver, lightly tried to press washer back on.

washer bounced off once, found it cuz it's shiny and light reflected off it-otherwise i may never have found it
got it back on, screwed well plate back on without losing the screws, plugged in, loaded tape, and IT WORKS!

play, ff, rw all ok. meters still no workee. next on the list.

ps-much thanks to the folks here for giving me the confidence to try stuff like this!
 
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runnin' #4 tonite. it's running like a champ!
this thing sounds really good. runs great as long as i don't put a too tightly packed cassette in it.

i haven't replaced capstan belt yet or fixed the meters but i thought i'd run it just to keep the other rubber parts up to snuff.

i just love these naks!!!
 
Would wrong size i-tire cause mr-1 to play fast?

my mr-1 #4-
just playing around with this deck tonite and it seems that it plays fast. it sounds great, but a little fast.
only thing i've done to it was put in the new i-tire last summer. the capstan belt still needs replacing and the meters still no workee. will fix those this winter, i hope.
also, the speed pitch control doesn't function at all.

1. for right now, tho, if the the idler tire is too big/small? will it cause the deck to play fast?
2. or would the non-functioning speed pitch control have anything to do with it?
3. a too loose/or tight capstan belt cause it?

T.I.A.
 
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The idler tire size does not determine your tape speed. Doesn't the MR-1 have a pitch control like the BX-300? That is where I'd look for the problem.
 
The idler tire size does not determine your tape speed. Doesn't the MR-1 have a pitch control like the BX-300? That is where I'd look for the problem.
hi. glad to know the i-tire isn't the cause.

the deck plays at a steady speed but a little fast until it warms up (after playing a tape for ~40 mins or so); then the speed gradually slows down and finally comes to a stop (after about ~15 seconds). i'm guessing the warmth from the heat inside the deck lets the elastic material in the belt expand and loosen.

or else, as others have suggested, the lube in the flywheel warms up and gets sticky and gums up the mechanism.
 
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Should be easy to tell! If the motor is still spinning but the capstans are not, then it's the belt. If the motors stopped, then it's the lube in the motor. The capstans have no lube, they are sintered impregnated bearings. They spin too slow it ever heat up and change the bearing property enough to stop them. Now if someone tried to grease them previously, then that would be a different story. No grease for capstans, only a drop on light oil into the bearing.
 
Should be easy to tell! If the motor is still spinning but the capstans are not, then it's the belt. If the motors stopped, then it's the lube in the motor. The capstans have no lube, they are sintered impregnated bearings. They spin too slow it ever heat up and change the bearing property enough to stop them. Now if someone tried to grease them previously, then that would be a different story. No grease for capstans, only a drop on light oil into the bearing.
cool.
i'll open it back up, maybe tonight, run it for a while and when it starts to slow down, watch the motor to see what it does.
 
cool.
i'll open it back up, maybe tonight, run it for a while and when it starts to slow down, watch the motor to see what it does.

most decks behaving like you describe has belt issues ;)

never seen a motor slowdown that way, they're normally running or not running.
 
most decks behaving like you describe has belt issues ;)

never seen a motor slowdown that way, they're normally running or not running.
i'll take a closer look at motor next time it happens.
motor may be running as normal but the warmed up belt gradually losing its grip and finally coming to a stop.
 
i'll take a closer look at motor next time it happens.
motor may be running as normal but the warmed up belt gradually losing its grip and finally coming to a stop.

Hi! This is my first post here, but recently got a MR-1 myself and figured I could share my experiences.

I think you might be on the right track. My bet is on the capstan belt as well.

I had a problem with speed stability... The thing would play great for like 10 15 minutes then it would gradually slow and then speed up a few times before finally slowing to a complete halt.

When I opened the thing up I could tell the belt seemed a bit loose and kinda dirty. I immediately ordered a replacement but at the same time I decided to try and see if I could get more life out of this one that was already here. It wasn't glazed or dry-rotted.. just a little dusty and a bit loose.

What I did was take some of the Roller Rejuvenator I had laying around (the stuff you get from Parts Express) and put it on a Q-tip.

I took the bottom plate off the MR-1 and turned it upside down because this gives you easy access to the bottom of the transport and the capstan belt. I powered up the machine so that the capstans began to spin and then applied the q-tip lightly to the top side, and the underside of the exposed belt... I then turned the machine off an let it set for a bit. After about a minute I started it back up and used a clean, DRY Q-tip on both sides... I got a nice amount of 'crud' off. I did this process one more time just to make sure the thing was good and clean. I then let it set for about 5 minutes and haven't had the speed problem since! Though admittedly, I've only put about 20-25 hours of play/rec time on the machine since. It may not be a long term solution, but if this works then at least you would know your motors aren't completely toast.

The only -slight- issue I noticed while doing this was that after applying the solution to the underside of the belt it wanted to slip around on the capstan pulleys... I'm not sure if it would come off or not but watch out for this. After drying out it self centered itself on the pulleys.


Lucky for me my MR-1 had the idler gear upgrade. Man I was psyched when I saw that!

As for the meters.. mine didn't work at first but one day just started to function. My guess is the internal wiring connectors were loose. If you haven't yet, I'd focus on that first.

Right now the only issue with my machine is that it seems to be stuck in "Timer Record" mode no matter where I position the timer switch. This means whenever I power up the machine it immediately tries to start recording. I have to make sure I eject the tape before I power the machine on or it starts to over record my tapes! Kind of a pain. One of these days I'll open it up and figure out how to defeat the switch and lock it into the 'off' mode.


Anyway, that's my experience. Hope it helps.

(BTW: My Capstan motor would come to a halt too. The belt did not 'spin' on it, but obviously my motor was not bad. I did not lube it at all. Just cleaned the belt, tape path, and pinch rollers and it now works fine. Don't assume motor until you know your belt is legit.)
 
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Hi! This is my first post here, but recently got a MR-1 myself and figured I could share my experiences.

I think you might be on the right track. My bet is on the capstan belt as well.

I had a problem with speed stability... The thing would play great for like 10 15 minutes then it would gradually slow and then speed up a few times before finally slowing to a complete halt.

When I opened the thing up I could tell the belt seemed a bit loose and kinda dirty. I immediately ordered a replacement but at the same time I decided to try and see if I could get more life out of this one that was already here. It wasn't glazed or dry-rotted.. just a little dusty and a bit loose.

What I did was take some of the Roller Rejuvenator I had laying around (the stuff you get from Parts Express) and put it on a Q-tip.

I took the bottom plate off the MR-1 and turned it upside down because this gives you easy access to the bottom of the transport and the capstan belt. I powered up the machine so that the capstans began to spin and then applied the q-tip lightly to the top side, and the underside of the exposed belt... I then turned the machine off an let it set for a bit. After about a minute I started it back up and used a clean, DRY Q-tip on both sides... I got a nice amount of 'crud' off. I did this process one more time just to make sure the thing was good and clean. I then let it set for about 5 minutes and haven't had the speed problem since! Though admittedly, I've only put about 20-25 hours of play/rec time on the machine since. It may not be a long term solution, but if this works then at least you would know your motors aren't completely toast.

The only -slight- issue I noticed while doing this was that after applying the solution to the underside of the belt it wanted to slip around on the capstan pulleys... I'm not sure if it would come off or not but watch out for this. After drying out it self centered itself on the pulleys.


Lucky for me my MR-1 had the idler gear upgrade. Man I was psyched when I saw that!

As for the meters.. mine didn't work at first but one day just started to function. My guess is the internal wiring connectors were loose. If you haven't yet, I'd focus on that first.

Right now the only issue with my machine is that it seems to be stuck in "Timer Record" mode no matter where I position the timer switch. This means whenever I power up the machine it immediately tries to start recording. I have to make sure I eject the tape before I power the machine on or it starts to over record my tapes! Kind of a pain. One of these days I'll open it up and figure out how to defeat the switch and lock it into the 'off' mode.


Anyway, that's my experience. Hope it helps.

(BTW: My Capstan motor would come to a halt too. The belt did not 'spin' on it, but obviously my motor was not bad. I did not lube it at all. Just cleaned the belt, tape path, and pinch rollers and it now works fine. Don't assume motor until you know your belt is legit.)
first of all, welcome to AK! sounds like you're in the right place.

i'll give belt the 'rejuve' treatment after i get some. belt already slips a bit (but only if i nudge it) as you describe.
if i take the cover off when playing it, the slow down/stop issues doesn't happen or may happen after 2-4 hours rather than 30-40 mins with cover on.
that tells me it might be a heat related issue with the belt-ie expanding and losing its grip from the heat.

re your timer switch. iirc, i've read that a squirt or so of deoxit in that switch, then work it many times to work the deoxit in, might 'cure' its issues.

re gear drive. the third mr-1 i bought last spring started stopping after playing about 40 mins of one side of a c90 and a bit of tape unspooling. i thought it might be the idler tire but when i opened it up, LO AND BEHOLD-the much ballyhooed GEAR DRIVE!
issue turned out to be the reel motor but a few shots of deoxit into the slits in the rear of said motor fixed that at least for the time being. it's been fine since.
edit-this deck also has a white dot on the back of the bottom panel which means it's a mr-1b with normal eq, as i understand it.

thanks to you and the other guys for your/their advice. :D
 
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been running this deck again tonite. it's been perfect. almost to the end of a 2nd c90, no slowdown or stop. still a bit fast but not too bad.
and it sounds really great!
i think the tapes i've played tonite are not as tightly packed (as some others are) which seems to make a difference.

edit-oooops!, spoke too soon. just in the last few mins of the 2nd side of the 2nd tape, it slowed. so i stopped it before it did itself.
didn't have it opened back up yet, soon tho.
 
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Here is one for you that maybe someone can answer. Is there anywhere for me to get a copy of the Service Manual and/or Owners Manual for the MR-1 for free, or would it be illegal for me to download a copy and should I just inquire to Nakamichi? I'm sorry I really don't know how that situation works. I've been working off the manual for the BX-300 that I found available on-line (because this was the commercial version of the MR-1) but they have some slight differences and possibly more than I'm presently aware of.


BTW thanks for the advise on the timer switch. I'm going to deoxit the switch later today when I have some time to pull the machine so I can get a good blast in it. Will let you know what happens!
 
Here is one for you that maybe someone can answer. Is there anywhere for me to get a copy of the Service Manual and/or Owners Manual for the MR-1 for free, or would it be illegal for me to download a copy and should I just inquire to Nakamichi? I'm sorry I really don't know how that situation works. I've been working off the manual for the BX-300 that I found available on-line (because this was the commercial version of the MR-1) but they have some slight differences and possibly more than I'm presently aware of.


BTW thanks for the advise on the timer switch. I'm going to deoxit the switch later today when I have some time to pull the machine so I can get a good blast in it. Will let you know what happens!
don't know about free serv. man. others may.
yeah, good luck with switch.
 
Ok, forget I said 'free' That's not really what I was trying to get at. Where would be a good value place to get one? (Free being the best value.) I'm sure going to Nak themselves is going to be the most expensive option? Should I keep an eye out on auction sites?

I can tell you right now.. this will not be the last MR-1 I own... I'm already in the market for good deal on another. Are other Nak decks significantly better for the increased price they command? I got this MR-1 for $50... I think it sounds great. It plays my tapes that I recorded from Mp3 for my car deck back in earlier 2000's (yes I still had only a tape deck in my car until about 2006) and it plays them almost better than my computer could play the mp3s. (slight exaggeration of course... but they sound great for being recorded from a computer hooked up to a late 90's Aiwa bookshelf system. I almost can't believe it.)

It's because of this I haven't had time today to even want to turn the Deck off and be able to deoxit the switch! hahaha!
 
Ok, forget I said 'free' That's not really what I was trying to get at. Where would be a good value place to get one? (Free being the best value.) I'm sure going to Nak themselves is going to be the most expensive option? Should I keep an eye out on auction sites?

I can tell you right now.. this will not be the last MR-1 I own... I'm already in the market for good deal on another. Are other Nak decks significantly better for the increased price they command? I got this MR-1 for $50... I think it sounds great. It plays my tapes that I recorded from Mp3 for my car deck back in earlier 2000's (yes I still had only a tape deck in my car until about 2006) and it plays them almost better than my computer could play the mp3s. (slight exaggeration of course... but they sound great for being recorded from a computer hooked up to a late 90's Aiwa bookshelf system. I almost can't believe it.)

It's because of this I haven't had time today to even want to turn the Deck off and be able to deoxit the switch! hahaha!
several months ago i emailed this place for an mr-1 serv. man. he has them.
$28, iirc. if i can't find a free one, i'll be ordering one from here.
http://www.vintageaudiomanuals.com/

here's a copy of the reply from vintageaudiomanuals-
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"Hi and thank you for contacting VintageAudioManuals,
We can provide a high resolution scanned, printed and bound reproduction of the following:

Nakamichi MR-1 Owner’s Manual
Nakamichi MR-1 Service Manual (several fold-out diagrams and schematics as well as a few service bulletins)

for $28.00 total, delivered to your door in the U.S. or Canada. International, please request new total. Manual(s) ships within 24 to 72 hours after payment receipt and is shipped via USPS First Class Mail (make sure to include your address with payment).

OR

We can provide a high resolution scanned, printed and bound reproduction of the following:

Nakamichi MR-1 Owner’s Manual

for $12.00 total, delivered to your door in the U.S. or Canada. International, please request new total. Manual(s) ships within 24 to 72 hours after payment receipt and is shipped via USPS First Class Mail (make sure to include your address with payment).

OR

We can provide a high resolution scanned, printed and bound reproduction of the following:

Nakamichi MR-1 Service Manual (several fold-out diagrams and schematics as well as a few service bulletins)

for $18.00 total, delivered to your door in the U.S. or Canada. International, please request new total. Manual(s) ships within 24 to 72 hours after payment receipt and is shipped via USPS First Class Mail (make sure to include your address with payment).

If insurance is desired, please add $1.50 per $50.00 of the grand total.
If you need it quicker, via Priority Mail, please let me know and I’ll adjust the quote for you.
If interested, I can accept payments via www.PayPal.com (paypal@vintageaudiomanuals.com), Money Order drawn on a U.S. bank in USD (USPS Postal MO OK too but we cannot accept the pink Canadian postal money orders), a Personal or Business Check (subject to hold for clearance) or well concealed USD Cash. Please refer to what manual(s) you are buying on your payment.

If you need me to send a www.PayPal.com invoice, please let me know.

Please make mailed payments payable to:

Mike Thomason
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The above quote is valid for 15 days from the date of this e-mail. Please let us know at your earliest convenience whether or not you intend to proceed with the transaction.

As a general rule of thumb, we do not sell electronic versions of our manuals for two reasons. First, the files are entirely too large, ranging from 10MB up to as much as 3GB each (these ones are 28MB and 132MB respectively). We do not reduce or otherwise try to make our files smaller at the expense of quality. Second, we do not want our manual scans ending up posted on other manual websites claiming them as their own. This has happened numerous times in the past and now there are some sites selling our work as their own (probably the best copies they offer based on what I've seen of their actual work). Lastly, the scanned files we assemble for printing purposes are different than those assembled to be a single pdf manual. Our files are produced with the specific purpose of being printed and not for being able to easily follow/read.

NOTE: For those of you who might think our prices are a bit expensive, please understand that all of our manuals are scanned, cleaned up and printed by us personally and are not cheap photocopies run on a high speed copier or scanner. Our manuals are as close to the original as you’ll ever get from anyone, including fold-outs. Also, the above price includes packaging for safe arrival and shipping, there are no additional costs. Please bear all of these things in mind when evaluating our prices. We can assure you that you will be pleased by the quality of our products, regardless of price or the economy.

Lastly, if you happen to have any original owner’s or service manuals you’d be willing to lend, trade or rent out for a few days, please let us know.

Thank you for your interest and have a great day!

Mike Thomason & Crew

Visit www.vintageaudiomanuals.com for all of your vintage audio documentation needs."
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i've never had one of the 'better' naks so don't know how much better or if they're better.
most i paid for any of my 4 mr-1s is $47+ 20 s&h. bx-300 for $31+$22 s&h.
onliest thing i had to do is i-tires in 2 of them. excluding #4, they all work perfect.
my nak 600 i paid full retail for :eek: it new back in '76.
 
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Thanks for the info jkay!

That price for both manuals isn't so bad, really... I'm starting to consider it.


How does the BX-300 compare? It's my understanding this is the consumer version of the mr-1, but doesn't it have some different features? I've seen a few people call the bx-300 a 'sleeper' nak.

I've started making recordings from vinyls to spare them (and my cartridge) the plays when I just want to do some casual background listening. The MR-1 has nothing short of impressed me so far in this capacity. Even using type I cassettes for a lot of them sounds fantastic for this purpose if you take the time to set the levels right.


Seems like you got some great deals on these things! I'd grab another mostly functional one in a second for ~$60 shipped!
 
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Thanks for the info jkay!
That price for both manuals isn't so bad, really... I'm starting to consider it.

How does the BX-300 compare? It's my understanding this is the consumer version of the mr-1, but doesn't it have some different features? I've seen a few people call the bx-300 a 'sleeper' nak.

I've started making recordings from vinyls to spare them (and my cartridge) the plays when I just want to do some casual background listening. The MR-1 has nothing short of impressed me so far in this capacity. Even using type I cassettes for a lot of them sounds fantastic for this purpose if you take the time to set the levels right.

Seems like you got some great deals on these things! I'd grab another mostly functional one in a second for ~$60 shipped!
bx-300 is pretty much identical to mr-1 'cept 300 has bias adjustment knob and rca ins/outs where mr-1 has 1/4" and xlr jacks and rack mt. hdware.
there may be other minor differences, not sure.

i'm thru buying cassette or r2r decks for a while as i have 2 amps getting recapped, etc. need cashola for those.
 
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