Hi guys,

Firstly, I want to say hi. I am a new member and I have been doing a bit of reading and the info available on this forum is unreal! So keep up the good work.

I have just bought my 2nd nsr, after selling the first to buy a gsx-r 750. Loved that bike but someone felt they needed it more than I did. Like I said, great bike, but I honestly think my old MC21 was more fun to ride, so here I am.

This time though, I bought a project bike. It is a Mk 1 MC18 that is mostly there, that came with a stack of bits, including a mk 2 frame with full loom, PGM 2, coils etc. Basically though, my question is:

The bike has been sitting for a long time from what I can gather, so there are a few things I plan to check before I try and start it. Namely, pull the pipes of and have a look in the cylinders for scuffing etc, if that is ok, then compression test (looking for somewhere between 100-140 on both cylinders), then going to check the coils with a volt meter as per one of the posts floating around, and put a drill on the oil pump to see if I am getting anything out there.

Is there anything else I need to do or check for before I try and get the old girl going? apparently it was running but a stationary drop cracked the water pump cover and it got put in the too-hard basket but you never know with these things.

Thanks in advance for your help,

Andrew

Sounds like you know what you are doing.
This is just stating the obvious I guess, but, I would also pull the carbs off and remove/clean out the float bowls and check the jetting and float levels are near standard.
Have a look at the reeds when the carbs are off.
Check for rust in the tank and fuel lines.
Check that the power valve motor works.
Check that (with the cables detached) the power valves rotate without too much force, and set them correctly.
Blow down the exhaust pipes to be sure they are not blocked.

All good tips, thanks Tuckerbag. Thanks mate.

I just pulled the pipes off and looked in the exhaust ports and everything looks great! the bores still have a nice cross-hatch on them too. This is incredibly relieving as this bike was a bit of a gamble.

The carbys will be coming off, and I have another set i got with the bike which I suspect are Mk 2 mc18, so I will do some reading there and see which would be best to rebuild.

Thanks again mate.

Come on Duggs.........We want photos !
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The list of things to check could get quite long if you were going to get fussy I guess.
As far as actually riding the bike is concerned:
Check sprockets and chain. Especially check for tight link joints by making sure the entire chain wraps nicely around the front sprocket without lifting off.
Check the fork seals are not leaking. It is pretty simple to replace the front fork oil. If on a budget just use cheap Automatic Transmission Fluid. It will be a lot better than the old oil.
Check wheel bearings
Check steering head bearings
Make sure brakes are working well.

I guess it is also worth pulling the fuel tap apart and cleaning it out. And check that the fuel hose from tank to carbies is in good condition.
Make sure that fuel does not run out of the carby overflows when the fuel tap is on. If it does then check needle valves and float heights
Maybe drain the two stroke oil tank and check that the oil light comes on.

I had planned to do chain and sprockets, fork seals, and steering head bearings, but the fuel tap is something I didn't think of. good call!

I am tempted to drop the engine out and get the frame acid dipped at the same time so it looks a million bucks.

I will put some pics up soon, but this is once I got her inside and took a few things off. Poor thing has been neglected a bit but I'll sort her out

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Ok guys, A little bit of an update...

Over the last few months I have been scavenging some bits that the old girl was missing, such as the water pump outlet housing, a set of samco hoses (the one i was most in need of didnt fit ) and a few other bits and pieces, and I am now in the position (more or less) to get stuck in and have a play.

I dropped the motor and gave it a degrease and a quick look over, the jammed it back in and connected everything back up. I've also pulled the thermostat and dropped it in boiling water, and sure enough, it opened right up. Win!

I also put 12v on the power valve motor (while hooked up), and there was movement, but it looked like the cables were restricting its movement as it only moved a few mm... does anyone know if this is normal? I have half a dozen spare power valve motors if not.

Tomorrows job is to pull the carbs off and give them a clean. I have mixed some 2 stroke in a coke bottle with some hose to the carbs, so hopefully I can get some proof of life out of it.

Wish me luck...

Bad news... Went out and bought a compression tester, and the old girl is showing about 85psi on both cylinders...

Does this mean a bottom end rebuild is required?


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Sorry if this is a bit too basic, but I like to cover off the basics.
Was the throttle fully open during the compression test?
It just seems a bit odd to me to get two evenly low readings?
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[color=#808080][size=9]Yes,.. I too know how to waste Time and Money,...

Oh, also check your reeds are sealing well, and look for blow back towards the carbs as you kick it over.
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[color=#808080][size=9]Yes,.. I too know how to waste Time and Money,...

http://nsr250.net/forums/viewtopic.php?t=12272&highlight=compression+tester
_________________
Andy.
NSR-WORLD.COM

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Tuckerbag: The throttle was closed for the most part, but I opened it toward the last few kicks to see if it made any significant difference. It didn't as far as I could see.

I will check the reeds for any visible sign of leakage, but not quite sure what you mean by carb blow back. How would I check this?

Andy: Thanks for the link, I thought I had found all the good threads on compression but I obviously missed this one.


Thanks for all your help guys. It is definitely appreciated.

Hey guys,

Update time, so post compression test I have decided the motor will need a top end rebuild at minimum, so I dropped the motor. First port of call though is to do a leak down test, which I plan to do with a bicycle pump, and some bungs to plug everything up, hopefully this weekend...

The other night, I came across a guy here in Oz rebuilding an MC21 on a cbr forum, and he is doing a beautiful job, and so I was inspired. Once the engine was dropped, I pulled the rear subframe off, and basically went to town.

Basically this is what I finished up with this arvo.





This is a little bit funny, seeing as I have been a little depressed about the prospect of what seems to be an impossible task of a bottom end rebuild.



Now to clean all the parts up... I wanted to ask if anyone had any opinions/experiences about treating the frame and swing arm bearing in mind that I would like to keep the brushed look? anodising? powercoating etc...

I would also love to hear any other tips and tricks for parts cleaning is welcome as this is a first for me...

Thanks guys

Thanks

Hey guys.

Not much has happened over the last few months, but I have started collecting parts again, and making sure everything is back together in anticipation for the little beast's first ride.

I do need a hand though, as there are a few holes in the side of the engine which that I have no idea what they are for (circeld in the image below).

Any help is greatly appreciated.



Thanks,

Ooh, I also forgot to post this...