eh up,

Wifey is going out tomorrow, so i have some free time to sort stuff on the tiger.

my main issue to sort is get it running better/more powerful.

Its a fully reconditioned 2.0 pinto 205 block and standard head/cams, with GSXR600 carbs, and a lightened flywheel.

the main jets are 160, and i'm using a bike fuel pump.

it runs fine and sounds smooth and sweet (so i'm pretty sure they're properly balanced etc), but it just dies above 4000rpm ish.

its running megajolt with a map found on t'interweb.

its got bucket loads of grunt low down, and will happuly light up the tyres from a standing start, but as it goes over 4000rpm the power wains off, and i get better acceloraiton from changing down. all the power is between 2000-4000.

surely this aint right.

so where do i start?

i do have a new head and cam to go on as discussed before, so i dont want to rolling road it as it is now, nor do i have the time, skills, knowledge, or parts to change the head right now.

i just want to improve it if i can. maybe change the jets or the mapping etc, but where can i get the jets tomorrow morning, and what sizes should i try?

i'm in the middle of cheshire and the only place i could see online that'd have them for sure is demon tweeks, a 1 1/2 hour round trip.

the only other thing that my help diagnose is the fact that when lifting off the throttle anywhere above 1500rpm whilst in gear (kinda engine breaking), it pops and bangs like crazy, and i mean lots of burbling and popping with and intermitted 2 foot flash out of the zorst!

any suggestions, cos i wanna get the most of the rest of the summer before changing the head etc over winter.

cheers,

martin

Have you tried Autosport labs site for a map?

Whats your ignition map look like?

Needs to be 36deg advance from 3500rpm upwards at WOT.

David

sounds like you need to dill the jets out a touch bigger if it is popping its running weak
mine used to do that till i drilled the jets out to 1.5mm

im running a 1640 pinto on zx6r carbs and it goes well

Check basic cam timing it may be a tooth out!
or try a bit more ignition advance higher in the rev range
good power low down but not high normally points to retarded timings
hope this helps
Ray

you need to be running 12 to 14 degrees min at idle with a standard cam 2% co min

Check map for rev limit, there was one that did have a really low limit, think it was 4k

Rich

If you want to try this map, this is what I started with and doesn't seem too far out.

Map Linky Calibrate the TPS as well then commit to flash.

Cheers

Rich


[Edited on 28/8/09 by RichardK]

Start by checking the basics ie valve timing , tappet clearances . It's often the simple things that cause the problems . If found to be OK then check max advance , rev limiter jets etc

Have you ajusted the needle height. there are 3 (IIRC) grooves with a circlip on each needle jet. You need to ensure that the clip is on the bottom groove (so the needles are raised). The jet size is nearer to 1.7mm.

I am running the same carbs on a 2.0 ltr pinto although on a dizzy. I had the exact same problems and the above solved things.

Cheers

Nige

Try reaising the needles first before drilling the needles. This should show are marked improvement on what you have. If no change the problem lies elsewhere.

I would go up a jet size for the 2lr from 1.6 to 1.7 sounds like the engine is starved at higher revs check the plug colour this will indicate if your running a bit lean try this first before altering any timing .as your engine runs ok at lower rpms then if no change look towards timing matters

well i've had a little tinker and it has noticeably improved, though i don't think its perfect.

now it seems to run through the revs better, but still with a little hestitation, though not as much as before, plus it doesn't pop and bang as much when backing off (though it still does a bit). on the negative side if i'm at part throttle below 1500rpm it stutters with a fair bit of black smoke out of the exhaust, if it floor it its fine.

alls i did was move the circlip on the needles, there is infact 5 of them, i had set it right in the middle when building the car, so now they're all at the bottom.

think i'll stick with it as is for now, then get the bits needed to swap the heads, and figure out how the hell i do that without blowing up the engine!

then on the way home in my truck 300yrds from home, one of the propshaft uj's has started to make a horrible noise and was very hot by the time i got home.

arse!!!

think its only £15 for a new one, then gotta figure out how to press that in next weekend!

Martin

[Edited on 29/8/09 by b16mts]