Yamaha FZR 250 help

**tigertim20** · 24th September 2008, 01:42

Gday people, have a problem with an FZR 250 I recently purchased and Im hoping somebody can help me diagnose the issue:
What happened.
Was riding along, and randomly the bike sort of lost power, it was like one or two cylinders just sorta stoppped working, I pulled over and held the throttle half open. After about 5-10 seconds, all cylinders went again, and it ran fine, did this a couple times, and now it wont start.
Ive replaced the plugs, and checked that I have spark, which I do.
Fuel pump is going fine.
Somebody told me it could be a carb issue, but im not sure exactly what he meant, how id check it, or how I would fix it if that was the case.
If anybody can advise what I should try, Id be grateful for the help, cheers.

**-easy--rider-** · 24th September 2008, 18:04

is it a strong spark? you can hav spark but it still wont run if its not enough.

**BBzz** · 24th September 2008, 18:15

EXUP valve maybe?
Cheek this site out all you need to know about FZR's and a good knowledge base of people to ask http://www.exupworldwide.com/forum/index.php
All the best Tigertim

**Dargor** · 24th September 2008, 18:43

Its not the exup.

I'm no machanic but the problem is with the engine/fuel-system, not the exaust system.

**BBzz** · 25th September 2008, 08:53

OK If it only dropped 2 cly, check the coils. If it’s the same as the 1000 they have two coils. Two clys share one coil.

**tigertim20** · 27th September 2008, 20:16

thaks for the help so far.
Im not 100% sure if it was actually dropping cylinders, it just sorta felt like that was the case, either that or it was losing a whole heap of power some other way.
Ive a mechanic friend who is looking at it at the momment, and he said that the compression seems to be down a bit, though Im not sure if that could be the problem, as the scenario posted in my first thread had happened 4 or 5 times over a couple of weeks. (bike was used several times daily) It was just after the latest time that it wont start now, dont know if this help as all!
though I do have two questions, 1)what compression should it be running/ how do I find out how much it should have? and 2, how would I check the coils and make sure they are operating as they should be? many thanks for all the help, id be lost otherwise!

**BBzz** · 28th September 2008, 09:53

Cly Compression is like a slow leak it happens overtime and once its gone Humm. Unless it's over heated.
Check out these sites http://www.fzr250.com/viewforum.php?...1e995d1966e60d
and http://www.exupworldwide.com/forum/index.php there is stacks of info there. I know I just read something on testing the coils but can't find it at the mo

**tigertim20** · 2nd October 2008, 04:33

SOOO, what are the potential causes for compression loss, and how expensive to fix?

**fatzx10r** · 2nd October 2008, 06:12

Originally Posted by tigertim20

SOOO, what are the potential causes for compression loss, and how expensive to fix?

squirt a we bit of engine oil down into the cylinder, if the compression is raised then more than likely you have worn compression ring's. if the oil does'nt do any thing you could have burnt out valves. that will give you a bit of an idea of what you may need to fix, so you can price up the part's

**tigertim20** · 6th October 2008, 04:06

Have had my mechanic friend do a compression test, all cylinders are around 50psi, and he reckoned they should be around 200 each.
So his diagnosis is that the timing has slipped. Im wondering what kinda damage this may have done. Im hoping (probably naievely that itll just be a mwtter of resetting the timing, although it probably wont be that easy)
He saud that the extent of damage would depend on whether or not a valve has hit a piston, so Im wondering what kinda likelyhood im looking at of that having happened, and why the timing may have slipped in the first place.
The whole point of the bike was a do-up project fpr profit that id put towards something a little bigger. so far it owes me a grand all told. I trying to gauge costs as to whether or not its going to be worthwhile fixing this timinng issue, as I know these are seliing for between 3, and 5 grand, so again, any advice, input, or vague quotes would be gratefully appreciated!!!!

**speedpro** · 6th October 2008, 10:08

I have a swag of FZR250 engine bits from a project both early and late model. Most bits are here though I carved up one cylinder and head. I have valves which are used but still probably OK which I think you will need if the timing slipped. You can have what you need if I have it for the cost of postage.

**tigertim20** · 6th October 2008, 20:24

That would be awesome, how can I get your email or something so I can contact you as soon as I know whats bent/broken? I would be extremely grateful!

**tigertim20** · 19th October 2008, 23:06

Ive discovered I need a new pick up coil,? (its the little thing that sits opposite the stator inside the magnetto casing, has a couple of wires coming off it). I need a new or second hand one of those, as mine is corroded and needs replacing.
I have a conclusion to the engine issue too. Turns out a buildup of carbon was preventing the valves from sealing, so thats been seen to, and put back together, now all I need is a pick up coil, which is frustratingly hard to come by, have had no joy from the local yamaha dealer, and cant find one anywhere, so if anybody knows of somewhere i cam find one, speak up!!!!!!

**speedpro** · 20th October 2008, 07:17

Tauranga rewinds have done good work for me in the past.

**tigertim20** · 30th October 2008, 19:51

foir the same bike, can anybody tell me the torque settings for the head, and the valve clearances? is the only thing from having my toy all put back together!??????????????