are you man enough for a manometer?...

[stevodude]

After last sunday ride with All, we were talking about the smoothness or lack of it of the ol' FJ, and he offered for me to pop around to his place for a bit of a tune up. But alas my afternoons are usually taken up with my offspring, so I thought I could wip up a manometer to see what was going on with the carbi's.

I had a look around and thought I could make one of the DIY sync carbi's.

After a bit of browsing the inter-webs, I shot down to the local hardware store for some 8mm tube, 5mm tube, 4 x 8mm joiners (which I didn't end up using), 2 x 8mm T joiners.

1 x 1200mmx300mm scrap wood from the shed.

Total cost 8 buks.

a few power cable thingo's you bang in the wall to hold the cables ( not sure what they are called).

join it all up and suck in some 2 stroke oil ( incase I suck some into the motor, then it won't damage tooo much :-) )

Aafter a 10 minute blat around the block, I hooked it all up to the 4 ports on the inlet manafold.
A
nd as I thought, nothing is even stevens :-)

results show that no 2 cylinders are even close to each other.

also show's further investigation into the motor required.

left to right is cylinder 1 ,2,3,4 ( No.3 is suppossed to be the benchmark ? )...

IMAG0079.jpg

[alpal]

shit that is quite dramatic hope that it is only sync, how long since valve clearances were done, would be doing a compression test I think, my sons CBR250R carbies were right out of sync but was mainly due to the idiot he bought it off not knowing what he was doing..

[stevodude]

yes I have a compression tester, but the smallest thread size on the end is 14mm ( designed for a car I guess), and the fj spark thread is 12mm.

wonder if anyone around town has adapters to go from the guage, has a connector like your normal compressor snap fitting, but smaller (about 9mm).

[alpal]

Hey Steve I think I may have 12mm sparkplug adaptor if that helps, I had adaptors in colourtune mixture kit I purchased years ago

[outbackbiker]

Hey Stevo, that is a way cool manometer, very good job mine is just some tubing zip tied to a cricket stump & filled with atf!!
I wouldn't be to concerned about comp testing yet , the imbalance you see on you m'meter is prob only a couple of inches of mercury differencial between pots, find the balance screws on the carbs, & adjust away you will be amazed at the smallest amount you turn them to bring the sync right again, the other thing you will find is as you just crack the throttle a very small amount they will change around again slightly , it's to do with linkages , just find a good comprimise between the 2.
The sync is actually not that bad first bike i did when i started the engine it was that far out one cylinder drank alll the atf,DOH!!!