Jukka Häyrinen

[Jukka Häyrinen]

I had to replace the fuel pump few years back, ‘cos it sometimes just stopped pumping. I thought it had been ruined by the the rust in the tank, so I bought a new 2nd hand one. I bought and installed a pump of an YZF750. Maybe the original pump only had the problem ‘cos of this wire thing :-/

[Jukka Häyrinen]

Copied from FZ750.com archive:

3.1qt (3,000cc) with filter change, 2.7qt (2.700cc) without filter change, 3.7qt (3,500cc) after engine rebuild. Also the level should be between the maximum and minimum window marks. PeterL.

[Jukka Häyrinen]

OK, that’s that with my investigation work then. US$5386 in 1986 equals 27 000 Finnish Marks (FIM), that’s for a NEW FZ750, well, I bought my 1st ’85 FZ750 in the summer of 1988, 2nd hand, ex track bike, painted all over (cool flake grey..) and scratch+dent in the other muffler. It was fast (most likely still had some tuning in it left, I’d love to know what it was..) The bike took easily to 260+ km/h (to N of word JAPAN), and yes it had the original exhaust still. I paid 38 000 FIM of it. U can count yourself blessed there ;-D Oh yea: sixhundredandsixtysiiiiiix!

[Jukka Häyrinen]

Hello! Well congratz for a great find B-) I dunno exactly, but there might be at least one blocked hole in the air take of the airbox. Also it surely has too little main jets. Probably smth wrong in the exhaust maybe too..?

Hehe, I remember when I saw a Swiss FZ750 (red one) here in North-Karelia in Finnland, in a little village called Juuka.. It must have been around ’86 – ’87, in the time when I was riding my R5 350 B-) Yea it actually was (is) the model B to be exact. Anyway, the red FZ was parked together with another Swiss bike in the parking ‘lot’ of our bank, and a Swiss looking guy was sitting on it. I of course didn’t know at the time that it would be restricted, found out about it years later probably.. 😉

[Jukka Häyrinen]

OK, thanx. I think I’ve read be4 from smwhr that this gear bearing problem appears at 70 – 80 tkm, so maybe ur bike is having it the 2nd time at 140 tkm.. So I may find it out soon if my bikes’ odo is in it’s 1st or 2nd round since it’s at 38 tkm now.. hehe..

[Jukka Häyrinen]

No prob. 🙂 I haven’t touched the air screws yet, and won’t do so until I’ve build that manometer to do it properly or smth.. (live 2 c that.)

[Jukka Häyrinen]

I wonder if anybody has built an EXUP to an FZ.. That FZ11s (or smth) guy in those pics from Japan would be my 1st suspect if so 😉

[Jukka Häyrinen]

OK, now I’m in a deeper trouble with the carbs.. Please Arch, can u tell what all u’ve tried with the 3k-4k problem? So I wouldn’t need to try the same things again and in vain. Thanx..

Edit: Lowered the needles one step back -> to the original hight, now it works again like in the beginning.. Maybe a bit better even, the butterflies were far out of sync originally, quick adjusted them with naked eye, now they r much closer at least. Should try the 122,5’s now again while the needles r back to normal.. *sigh

[Jukka Häyrinen]

Congratz for a great bike (once u’ve got it in one piece first;-) I don’t have much of spares at all.. U surely have tried German and UK ebay too? Can u please tell the odometer reading (miles or km’s) of that FZ of yours? That might help me to determine, in the future, if my FZ’s odo is on the 1st or 2nd round.. Hopefully not very soon though. It now has 30 smth.

[Jukka Häyrinen]

Hi, I should have one spare.. painted one.. somewhere.. But I’m in Finnland and alone postages would be 31 €uro.

[Jukka Häyrinen]

OK, got tonight confirmation to my feeling of more power; TDM 900 was left behind a lot faster now in a drag race 😉 The cause was also helped by the lost weight during the drag race; side stand parted ways with the rest of the bike at about 200 km/h 😀 My friend stopped to search it (he saw the departure), and I joined into the search, but we couldn’t find it. I wonder if it would be possible to make the side stand out of aluminium.. This friend of mine works in a welding company, so he maybe could help in the making.. Anyway, found also that I have 122,5 & 125 & 130 & 142,5 main jets in the kitchen closet, I’ll try those too starting from the smallest ones.

Addendum to the 3k problem: if going 3k @ 3rd or 4th gear, twisting gas makes the bike accelerate somewhat ok, unlike @ 6th when nothing happens.

[Jukka Häyrinen]

Carry on the good work!

I’ve now noticed some unnecessary pipes and brackets in my FZ chassis too.. 😉

[Jukka Häyrinen]

Yea, I found from FZ750.com archive that 3k rpm problem being a common problem with 4-1 systems in FZ.. There also read that with different pilot jets and dyno time it may be possible to solve.. Oh well, Arch, what have u tried so far..? 😉 Yea, I would think a FZ from -87 onwards with 4-1 originally, don’t have this problem. Maybe should try find out what’s inside their carburetors. Anyway, I’ve changed this most sweetly carbureted bike into a monster! 😀

edit: and I’m not planning to give it any dyno time.. So I guess cleaning carbs, messing with pilot jets and jet needle is about all one can try, and probably try in vain too..

[Jukka Häyrinen]

Hi Scott, found this with google: http://www.fz750.net/history/prefix.htm 😉

[Jukka Häyrinen]

Hi! What happens between the first *click and the 10 seconds? It doesn’t rotate the engine the way it should when pressing the start button? Anyway, if u press the start button and it clicks and doesn’t rotate the engine, only the starter motor rotates, u should stop pressing the start button.. Sounds like some pinion or smth in the starter doesn’t catch properly. I haven’t had problems with it yet, so I dunno how to fix it.. Probably a good cleaning will do. Lets wait for professionals opinion.

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