Picked myself up a 3LN3 for $300 the other day. It needs some attention to put it lightly, essentially everything will need going over but that's perfect to keep me busy over winter. Bike was stored undercover apparently but I can clearly see water in the engine. Carbs and tank were off. So the plan is to rake it out and turn it into a Cafe racer/cruiser with custom seat and new tank, pod filters etc. Just kidding . The plan is to fix it up to race bike condition or very tidy roadbike conditions (depends if I can find a proper 3LN3 headlight...). I'm starting with the carbs and trying to resist the urge to work on too much at once. Engine head got pulled yesterday because of all the schmutz I could see in the intakes and there's some cylinder rust but it's all wiping off so far. It should look great next to my 2KR. Getting a real little collection happening now. Sent from my SM-G991B using Tapatalk
SCORE! That actually doesn't look to shabby, there will be [unwelcome] 'discoveries' awaiting you, but that's always the case. Glad that cafe racer conversion was a joke otherwise even your cat, dog or goldfish would not be safe. BTW Check gumtree for bodywork also - IIRC there was someone in QLD that looked to have a significant amount of parts Ad is still up https://www.gumtree.com.au/s-ad/wit...ts/yamaha-fzr250-2kr-and-3ln-parts/1187188126 The 3LN3/5 frame is slightly heavier than the 3LN1 as Yamaha added some stiffness, but a significant step up from the 2KR frame IMO as it's a Deltabox - I wish I could relocate the article that claimed that the FZR400 [and likely the 250 frames] were designed by the GP team working on the YZR500 GP bikes. That would readily explain the performance of the FZR400's handling wise and I reckon the 250's are potentially in the same league with some suspension work.
Nice score. A word of advice on the headlight. I have only ever seen one correct twin projector headlight that the 3LN3+ are supposed to have, and it's on @Grasshopper 's 3LN6. Almost all of them have a TRX/TDM 850 headlight, to meet Australian design rules. Must have a 55/60w headlight. A lot of the 250 imports have 35/35w headlight bulbs, which the twin projector unit on the 3LN3+ are meant to have. The TRX/TDM headlight is a 55/60w H4 globe. My ZXR250 had either H6 or H4R globes in it, and they were 35/35w. CBR250RR (MC19/22) use the same 35/35w globes
Interesting stuff, so in a pinch the TRX/TDM850 has the same curves and mount points as the 3LN3/5/6/7 and can be substituted. That dual projector in @Grasshopper's 3LN6 sound good, my 3LN1 headlights are pretty poor and have plastic lenses YUK!
The twin projectors are proving quite hard to find online. There's a few on Japanese auction sites for around 80 AUD so I might splurge and get one from overseas cos they do look so cool Sent from my SM-G991B using Tapatalk
Some people should not be allowed to work on vehicles... this is the exhaust if it's hard to tell Sent from my SM-G991B using Tapatalk
It should come as a shock to most of you but finding a replacement slide and diaphragm cap is actually not very easy. Dunno how it got broken as its decently thick plastic and carb 3 isn't usually something that breaks in a crash. Anyone happen to have a parts carb they would sell? Picked up an ultrasonic cleaner but the degreaser I used turned my carbs black. Very clean, but ugly oxidised black. Very annoyed by that so ill likely sodablast them once I fix the air compressor. Sent from my SM-G991B using Tapatalk
Try a hot dilute solution of either citric acid or cream of tartar to bring back the shine, it makes it easy to wipe off Otherwise you could make up a paste of either and use a toothbrush if you're a masochist, it also works for brass. It tends to be the brass and other metal parts that cause the aluminium to blacken for some reason in the ultrasonic
The black goop you get from an ultrasonic cleaner is because you have water, dissimilar metals and heat. Plus the cleaning agent. What you have is a form of electrolysis. Essentially when you dunk everything in the ultrasonic you make a battery of sorts. I don't have this issue when using CT-18 truckwash mixed into the water at high concentration. Using any type of solvent or cleaning fluid and you will get black aluminium. Good news is it's easy enough to clean off, just soak the body in threebond engine conditioner and wash with hot water after.
Well that's a pleasant suprise, that it cleans up so (relatively) easily. I'll get on that Sent from my SM-G991B using Tapatalk
Yep you've gotta be careful when using any high alkaline or caustic degreaser on aluminium. It will rapidly oxidise the surface and turn it black from the aluminium oxide . Heat will speed it up aswell. You'll see the surface of the part foaming . Some Ali Brite will clean it up .
I've never tried it myself, but would soaking the blackened carb bodies in Coca Cola or CLR do the same? @neoncrypnid if you get a moment to test it, can you smear a bit of Tomatoe Sauce on one of the carbs and let it sit for a few minutes to see if that does anything? Good opportunity to get some facts. Also, with your broken carb bits, could you 3D print replacements?
I got a bit excited with the new toy and didn't test anything before chucking one of the carbs in but I stopped once I saw the oxidisation. Ill definitely try some coke and sauce out. Can anyone recommend a better degreaser that doesn't oxidise? I'll be removing brass parts from now on too. 3D printing will probably be the plan. I need to work out what type of plastic the slide is to repair it as i doubt I can print an entire one accurately. It's just the diaphragm area that's damaged so worst case I could maybe glue the diaphragm on with fuel resistant goop, it just has to hold a small vaccum. Sent from my SM-G991B using Tapatalk
You could scan one of the other diaphragm covers and try printing that, but I do agree it won't be an easy thing to 3D print, so maybe glue & a prayer is your best option. Good Luck.
With a new diaphragm installed, it actually looks alright. Polypropylene filament is meant to be fuel resistant, but at $100/kg it's not cheap. I'm thinking of getting some HTPE sheeting and cutting 'patch panels' and gluing them over the holes. Add some decent gasket maker and it might come up alright. The cover might be harder to do cosmetically speaking but that can be sorted later. Sent from my SM-G991B using Tapatalk
A lot of degreasers these days ruin aluminium. I avoid them like the plague. Water soluble used to be great, but I believe banned now. What is going on with the diaphragms? You need new ones?
No I got some new ones as part of an aliexpress kit, the old ones are cracked and old, but that reminds me I will be ordering a seal kit from you soon too Sent from my SM-G991B using Tapatalk
I truly do not know how it got so badly damaged. She's had an abusive owner in the past sadly, but she's in (hopefully) good hands now. The more I look at it the more confident i feel about fixing it with some HDPE sheeting, a dremel and some glue. Sent from my SM-G991B using Tapatalk