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Here is a little background first.
'88 1127 (GSXF not GSXR)
Pre 750 carbs (Arsenic cleaned)
Stock post 750 electrical system (working just fine in April/May)
OEM Airbox/filter
I've gotten to the point of finally getting this thing running and as expected I have run into some problems. It will start but "runs" pretty bad. Not all cylinders are firing all the time and it only stays running on full choke. Anything less and it dies. Since the electrical system was working just fine on the bike before I think I can cross it off the list. Since they are asenic carbs, I think I can cross dirty pilot circuit off the list. That leaves compression and air.
A cold compression test tonight gave me values of 150, 150, 132, 141. Given they are cold numbers, I suspect that compression is good enough.
Next is air. Stock airbox and new OEM filter so off to a good start. The next air factor would be vac leaks. I am using old (kind of hard) intake boots. No visible cracks (ok some small ones out by the bolts, but not where it matters) but hard. Similar story on the airbox side. Those aren't near as hard, but certainly not nice and supple. I tried doing the "spray carb cleaner" test while it was running and didn't notice anything, but it was running so bad that I don't really trust the test.
Another issue I think I may have is regarding the alignment of the intake boots. During this process I discovered that the carb spacing of pre and post carbs are not equal. So I got some pre 750 boots from 542 (thanks btw) and put these on the 1127. Well, the alignment on the head is not very good. I didnt take notice at the time of installation, but now I'm thinking it could be a problem. Here are some pics:
The o-ring does sit on the machined face, but in some spots it does overhang the edges a bit. I know this isnt a good thing, but I also cant think of an easy fix.
I read somewhere that certain early year 1127 engines ran 36mm carbs. I'm thinking that maybe those will fit the head better and still have the spacing of pre carbs.
As far as the poor running my suspicion is that some massive air leaks are causing some of the cylinders to fire, but only on full choke. (Plugs range from slightly wet to very wet - again taking the pilot circuit out of the equation).
Im open to some input/questions..
'88 1127 (GSXF not GSXR)
Pre 750 carbs (Arsenic cleaned)
Stock post 750 electrical system (working just fine in April/May)
OEM Airbox/filter
I've gotten to the point of finally getting this thing running and as expected I have run into some problems. It will start but "runs" pretty bad. Not all cylinders are firing all the time and it only stays running on full choke. Anything less and it dies. Since the electrical system was working just fine on the bike before I think I can cross it off the list. Since they are asenic carbs, I think I can cross dirty pilot circuit off the list. That leaves compression and air.
A cold compression test tonight gave me values of 150, 150, 132, 141. Given they are cold numbers, I suspect that compression is good enough.
Next is air. Stock airbox and new OEM filter so off to a good start. The next air factor would be vac leaks. I am using old (kind of hard) intake boots. No visible cracks (ok some small ones out by the bolts, but not where it matters) but hard. Similar story on the airbox side. Those aren't near as hard, but certainly not nice and supple. I tried doing the "spray carb cleaner" test while it was running and didn't notice anything, but it was running so bad that I don't really trust the test.
Another issue I think I may have is regarding the alignment of the intake boots. During this process I discovered that the carb spacing of pre and post carbs are not equal. So I got some pre 750 boots from 542 (thanks btw) and put these on the 1127. Well, the alignment on the head is not very good. I didnt take notice at the time of installation, but now I'm thinking it could be a problem. Here are some pics:
The o-ring does sit on the machined face, but in some spots it does overhang the edges a bit. I know this isnt a good thing, but I also cant think of an easy fix.
I read somewhere that certain early year 1127 engines ran 36mm carbs. I'm thinking that maybe those will fit the head better and still have the spacing of pre carbs.
As far as the poor running my suspicion is that some massive air leaks are causing some of the cylinders to fire, but only on full choke. (Plugs range from slightly wet to very wet - again taking the pilot circuit out of the equation).
Im open to some input/questions..
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