Project My '90 FZR250 3LN3

Is under the carby's dark enough ?
I'll make sure they are soaked in Dielectric grease before i fit them, the XV250 manifold is still shiny from the grease coating

 

Yeah i'll get some jet's ordered soon.
Took the FZR out this morning around the block with the mixture screw's at 2.5 turn's out, the exhaust had a bit of a burble, response seem's ok, but on the road it won't pull away off idle too well, and i can hear a bit of popping in the exhaust so it's back to 2.25 turn's for the moment.
All the cylinder's are very close to 18" Hg vacuum and steady, and exhaust temp's are around 200°C

Thinking i might up the pilot's one size to a #12.5 and even try a #15

 

Yeah from japan-webike $34 US per kit-
https://japan.webike.net/products/23216010.html

They have the kit's for MC22's for $38US ea plus post, you'd have to ask them to send to Australia
http://www.ebay.com/itm/162655095857?rmvSB=true

 

I've had another go at tuning it this arvo, but i can't make a difference with the mixture screw
I reckon the new Repco fuel filter can't flow enough, enough to keep it going at idle and just above but not over 4000 rpm.

 

I can't afford 4 of them just yet, will just try the Pilot's first

Yeah i know, i'm almost ready to use some wingnut's to mount my tank.
I've ordered an alloy/glass filter from china, $4.65, and will go see my mate who run's a Speed shop tomorrow too and see what he has as well

 

Because they arent running perfect or close to perfect.
Mainly to get rid of the slight hesitation at 3000 rpm.
Think i found part of the problem today.

I was thinking about the pilot jet and was going to fit one size bigger in the carbs to get the mixture screw closer to the standard setting of 3 turns out.
But realised i'd need a leaner Pilot jet to be able to richen the mixture screws (not sure if Mikuni make one smaller though)
Then i remembered that just off idle the carbs start running on the needle and needle jet.
When i fitted the Keyster kits i found that the plastic spacer under the needle clip felt a bit loose on the needle and may have caused wear if i used the new spacer because the needle can wobble a bit.
So i used the original spacer on the needle.
Today i took the needles out and compared the Original and the Keyster spacers and found that the Keyster spacer is .16mm thinner.
So with the original spacer it lifts the needle out of the needle jet and makes it a touch richer off idle
I reckon being a touch richer it might be giving me that slight hesitation.
I have fitted the Keyster spacers in now to see if anything changes.





I soaked the original fuel fiter in some Threebond for an hour and gave it a thorough clean and blow out this morning as well.
Then i checked if the Repco filter restricted the flow by doing a blow through comparison.
The repco filter is about 50% harder to blow though so that might be causing the latest problem of it not wanting to rev over 4000 rpm.
The original filter is now back in and i'm just waiting for an hour or so without rain so i can check that out too.

 

Had the FZR running again today, tuned it and took it out for a quick ride, still wont rev over 4000rpm

Thinking now that the coil relay mod that i tried the other week might have damaged the TCI ?
Popped that open this arvo but cant see anything unusual there, will need to remove the diode's, transistor's and cap's off the circuit board to check them out and replace what i can




Lot's of surface mount resistor's on the back of the board!




A quick diagram showing the easily replaceable componant's , their part number's and location in referance to the circuit board (Not the 2x IC's at the top)

 

Started giving the original TCI a tune up today, the capacitor's have a limited life so i've picked up a set to go into my ignition box, along with a couple of new transistor's
Total cost for the part's was $8 for 7 cap's and 2x transistor's from Jaycar

I was able to find better capacitor's that are rated to a higher voltage and a higher temp so should last a bit longer than normal.
New cap's are fitted,
I still need to swap the 2x transistor's but will test it as is atm so i have something to compare it to once the new transistor's are fitted too
The new cap's will need to be anchored with some epoxy to keep them from vibrating and to help transfer some heat away from them

 

The 2x ZT2198 Darlington Transistor's above didn't work, had no spark.
Found i they needed to be insulated for the heatsink to prevent them earthing, something Jaycar didn't mention.

I searched online for some new transistor's same as the original's and ordered a pack of 10, they arrived friday arvo.
Today i removed the incorrect one's and fitted the new one's to the circuit board
The old one's are on the bottom of the 1st pic.





And the new one's fitted to the TCI.

 

Nah not yet,
i still need to mix up some epoxy and and put it around the new capacitor's to stop them vibrating and clip the box back together.
The new manifold's have been port matched to the head and fitted, just need to set the fuel level's and mixture's again.
I've made up a carby stand to set them while on the bench and will use my spare FZR fuel pump too.
I also want to check how many amp's the coil's are pulling, and want to try and measure how many miiliamp's they put out too.
And then while i'm at it will test it with the standard coil's too so i can compare reading's.