Yet another 3LN1 Rider

Hey Everyone,

My name is Aedan and I'm a mechanic at Ebbs Motorcycle in West Auckland, New Zealand.

Been reading allot of info at FZR250.com and decided to signup here as they recommend since I own a lovely little 3LN1 named Bagheera(Black Panther). Got allot of modifications and maintenance on the cards, First few have been done already.

First off I cleaned, balanced tuned the carbs. Made a new air filter. Done valve clearances. Heat Wrapped the header pipes in fiberglass wrap. Since then I have relocated the Ex-up Actuator under the tank in preparation for tail chopping her since I never plan on having a pillion and always wanted to do a street-fighter.

To do;
Front Forks(change oil, more preload, shorten springs and longer spacer)
Tighten Rear Suspension Preload
Rear Tyre(because Shinko tyres are a hospital pass)
Tail Chop(New Rear Lights too)
Relocate Coolant Tank
Fit Trail-Tech Dash
Motocross Bars+Risers+Grips+Levers
Different Headlight
Clean up loom
Polish Engine and Frame
Paint Tank & New Rear Panels
Re-Position Pegs(Maybe new hangers and Pegs??)
Muffler(Make a new one or Fit a different one)
Oil + Filter(Trying out Penrite 15W-50 Full Mineral, anyone used it yet its new to NZ markets)
Yeah lots to do....

Here is some photos since everyone loves photos(Sorry their from facebook);





(Ok ill stop spamming photos now)

 

Thanks for all the info, already done valves and I used a treatment to soften up those rubbers. Worked a treat. Fuel filter was replaced, pump flushed and carbs were beautiful inside just a partially blocked idle jet.

I do need the rocket cover gasket however. So will be ordering that. Photos are a tad old, but she rides great already had her off the clock dispite the atrocious rear tyre.

 

Carbs, in lovely condition for a 26yo bike. They have probably been replaced.

 

Yeah 1 and 4 do now, one was siezed and broke off when I cleaned it. Had to drill and tap the whole thing! I'll have to buy some brass bolts for it when I pull the carbs next. No rust tho luckily, nothing new. They will be off when the engine comes out to be cleaned in a few weeks.

 

Nope I did mean full mineral, simply because the gaskets are 25 years old. Synthetic oils are known to cause issues with old gaskets because back then they were not made to accomodate the additives used today. So because I don't want to wreck gaskets I'll use full mineral till after I've rebuilt her(when she needs it). Also older oils had more zinc in them, and zinc is known to reduce engine wear and promote gasket life. So Penrite is a good choice because of high zinc concentrations.

That's why I said I will be trying it out, and at 35$ NZ for a 4ltr why not. Will let you know how it goes I'm doing it this weekend.

From past experience working on older bikes running synthetic in bikes designed for mineral is generally a bad idea. Seen far to many bikes leaking from the crankcase come into the shop I work at.

 

Its fairly common knowledge between us mechanics, The engine was designed in a time when Synthetic oils were not a huge thing.

The gaskets were made to retard mineral based oils because that was the thing at the time, the rubber they make all the seals(eg. Valve Guide Seal, Output Shaft Seal & Gearshift Shaft Seal) were made with the intentions of retarding the mineral oils. Its not a "It will happen" thing, Its a "If its thinking about it, it probably will now" kind of thing. Id rather just avoid the issue completely and run the oils the engine was designed to run.

And also the newer oils are usually comparable in weight hot and cold, they are designed to lubricate better and flow faster. This is great for engines that are newer and use smaller oil passageways and oil gaps. But in older engines designed with larger oil gaps to accommodate heavier oils, a faster moving oil is bad because the principle of the big end bearing is the connecting rod spins on a film of pressurized oil(Oil Cushion) that prevents wear to the actual bearings. So when a lighter slipperier oil that moves faster is pumped into a large gap(Example of big end bearing) it takes more pressure to maintain the same amount of lubrication or "Oil Cushion" to prevent engine wear. So long story short, Running Synthetic oil in a engine designed for mineral will cause 3 things; More Wear, Possible Leaks, Less resistance(so easier to spin).

That said, normally a semi-synthetic oil is fine because its a mineral base oil blended with additives to make it lubricate better. That is what we use in the shop for Japanese and European bikes. Harley Davidson we use a oil made specifically for them.



So this evening I got started with the oil+filter change, Man i was disgusted at the oil filter... Makes me feel bad for taking her off the clock a week ago! More lovely pictures;


I also did some minor repairs to the "Frame Sliders" since I can't be bothered sourcing new ones yet, More photos;

So there was a few places where they had ground through and was able to leak water into there, So i sandblasted it back and epoxy resin'd up the inside to seal the leak. Then covered it in good old bog, did away with the yamaha logo too simply because I would like to keep people who don' recognize the bike when I'm done guessing. Left that to cure when I went home from work tonight. I got a lovely low gloss black engine enamel to put on when I'm done.

Tomorrow I'm getting started on the other covers and planning the bum chop since I finally found a nice flush led stop/tail light. More photos;


Can't wait!