Suzukisam77

Update (problem seems to be fixed) did a bench test on the carbs and I had a leak on 3. Fuel was leaking out of the air jet and also the needle jet. So I took a look at the floats and they were jamming up. I was able to bend the tangs in a way to free them up but keep my float height and it seems to run good again.

Update First off thanks for all your guys help so far I have tested my fuel tap and it’s working properly. It flows fuel when vacuum is present and doesn’t flow when there’s no vacuum. I think I’ve determined that it’s gasoline in my cylinder because I took a sample and it smelled like gas. So I’ve taken the carbs off and have been testing the fuel needle and seat and they hold 6 psi pressure with a pressure gauge so I assume these are good. I replaced the needles and seats after I bought the bike with an all balls kit, they fit very loose and very wobbly is this normal? The fuel floats themselves don’t appear to be in very well even when I replaced the orings with oem. In addition there are no o-rings on the emulsion tubes, I’ve heard these emulsion tubes can get worn out and cause excessive rich condition. Any thoughts on this or what else I should check while I’m in the carbs? @wraiththe spark plugs come up sooty and black even after 10 minutes

1-3 are like this , 4 is dry

Here’s a picture of the inside of a cylinder

I think I’ll have another look at those carb floats and needles seats when I get the chance. maybe it ran great at first because there wasn’t enough gas in the bowl to flood it but then it started leaking fuel into the cylinder because fuel level got to high or the needle valve wasn’t stopping flow.

@wraith interestingly I don’t see any smoke coming out of the exhaust which is now making me question if it is oil but actually gas mixed with carbon that just looks like oil like @fatblokeonbanditis saying. That thought did cross my mind as to why it wasn’t smoking if it looked like there was oil in there. Yeah I’ll try and get a thermometer and measure the exhaust temps.

@imago Yeah I think your right. The valve stem seals I used were aftermarket from the Athena gasket kit not sure if they need to be Suzuki or not because the Athena ones looked different and they didn’t have the metal rings at the bottom, only on the top. Maybe they aren’t fully home because I just pressed them in with my fingers and I didn’t notice any click.

@imago Ok I will try this and let you know how it goes. I thought the only way for oil to enter from the valve head would be through the valve stem seals which I replaced but the wear of the valve guide has an effect on this too?

@Swiss Toni Yeah I made pretty sure of the orientation of all the rings before I fitted the barrels. They had letters on them marking orientation. I maybe thinking now that the bores have gotten too wide as I checked them with a telescopic gauge and they were very close to the manuals service limit like .08mm away. I’m just finding it hard to believe they would get that way after 23000 miles?

Are the valve guides hard to remove and inspect?

@wraith Well it’s only got 23000 miles on it so I wouldn’t expect this kind of engine wear either. The oil seems to be in cylinder 1-3, cylinder 4 seems to be dry. And yeah I did replace the 6 o-rings that go on the head gasket around the studs. I did not check the valve guides themselves but i did check how much the valves moved from side to side in them, and they didn’t move very much side to side.

Hi my names Sam and I’ve been having engine problems with my 97 Bandit 1200 ever since I purchase it a few months ago. I’m wondering if someone here can help me as I don’t have a lot of experience in diagnosing engine problems. When I first purchased the bike it ran good when seller ran it for me so I bought it. As soon as I got it home it ran horribly, hard to start and would barley stay running. I did a compression check on all four cylinders and cylinder 1 came up low at 130 psi while the others were 160 psi and head gasket leaked. When I added oil it shot up to 180psi so I though it must be rings. So I then took apart the engine and installed new rings and new had gaskets etc, also I honed the cylinders with a hone from harbor freight. Reassembled and it ran great and was 160psi across the board. The next time I fired it up it sounded horrible like a cylinder wasn’t firing or something, and would also backfire heavily. I take it apart again and find oil sitting on top of the cylinders. So this time I replace my valve seals as well as cleaning and lapping my valves. Put back together and wow it runs great. Again the second time I fire it up runs terrible again same as before. I look inside the cylinder with a bore scope and yep oil in there again? Anybody have any ideas on what went wrong or what I should do now? Thx