Hi friends! I apologize for my English - he studied it in school 6 years ago. I am writing to you from Russia. With the help of Google came to your forum! I am very glad that I found the club owners Yamaha FZR400/R/RRSP!
Since this bike is not common in our country, to find spare parts is a big problem! My bike (Yamaha FZR400RR 1989 3TJ1 1WG engine) has recently started to smoke heavily blue-gray smoke after 8K rpm
By this I decided to pack up wasted 56.5mm.But I faced a serious problem in the choice of piston group. Find the original pistons and rings on 3TJ model I could not (3TJ-11636-00-00; 3TJ-11610-20-00). But I managed to find suppliers 1WG-11636-01-00;
1WG-11610-20-00 for the FZR400 88-90 years. Prompt, whether they fit the pistons and rings in my engine?

What I'd recomend is replacing the 400 with a 600cc engine but you might not be able to find one of those.

So how about a big bore 426cc kit ????
http://www.tts-performance.co.uk/yamabore.shtml this should give you a Piston Kit and Head Gasket

if you can get a re-bore done fairly cheep then there's some options you can check out here

http://fzronline.com/wiki/doku.php?id=d ... ment_chart

442.90cc sounds good + 3mm bore with fzr600 pistons might be easier to get than over sized fzr400 pistons

don't know of anyone doing it but it's apparently doable, although if you go down this route it'd pay to open up the crank oil ways a bit, not a problem on road going fzr 400 3tj but the racers often open them out for better oil flow to the crank and 43cc is a fair jump up




EDIT
i seem to remember iv'e read somewhere that the 3tj can only be re-bored to +1mm,
the above chart states FZR 400 RR which is the 3tj, but the yanks never got the 3tj (and fzr online is an american site)
so i'd check it out before going the hole hog, cos if it's gonna need re-sleeveing, it's not worth it, a gasket set alone is £120 and that's before you pick up a spanner

Hogdigerdy Dog wrote:EDIT
i seem to remember iv'e read somewhere that the 3tj can only be re-bored to +1mm,
the above chart states FZR 400 RR which is the 3tj, but the yanks never got the 3tj (and fzr online is an american site)
so i'd check it out before going the hole hog, cos if it's gonna need re-sleeveing, it's not worth it, a gasket set alone is £120 and that's before you pick up a spanner

That's what I thought, which is why I was looking at the TTS kit. They didn't quote a liner so I assume they were ok in the 3TJ's.
I think the +1mm is the biggest overbore because those are the biggest pistons available from Yamaha and it might be in the 400 racing rules.

Of course he might be able to hone the bores and use a piston ring kit ... just depends on what he finds

according to the fzronline chart the +2mm takes you out to 428.02cc
which is close to the TTS 429cc so perhaps you can go +2mm on the bore (i expect they rounded it up )

but i agree if the bores are not to scored then a hone and ring kit might be the cheapest/easiest option to a smoke free motor

with gaskets, honing and ring's it's gonna be a £350 job at least and that's if you build it yourself, so i'd probably go with a used engine
but maybe not in russia

True it's expensive but you'd decoke it and relap the valves and the engine would be good to go for another .... 20,000 miles.

1WG pistons are about 1mm taller than 3TJ pistons. It would be a lot of work to use them, adjusting the cylinder base gasket with a spacer, and cam chain length.

Shimmiel states he has "(Yamaha FZR400RR 1989 3TJ1 1WG engine)" if it's a 3TJ1 - 1989 then it'll be a jap export bike which as far as i know all had an engine number of 1WG
the earlier frame numbers started 1WG up untill the 3TJ1 which starts with 3TJ1 but i thought the engines all had 1WG and nothing else on them if they were jap exports,
the british model 4DX had a 4DX prefix frame and engine number but these are 1992 onwards

Plus 2mm is possible on the 3tj bores gives something like 440cc i think and prob good for 3 to 5 bhp right through the rev range. Not sure who does the pistons but my engine builder has made one for a customer to run in mini thunder bike i think. Kicked out 86bhp if i remeber the conversation. Obviously a little more work involved for that sort of horse power but i would think 62 bhp would not be out of the queston.