[Mister E]

I've owned my 92 900ss for a few months now. This is my commuter bike so I've already managed to put about 5,000km's on it.

I've noticed a couple of times recently when checking the oil that there appears to be some stuff that looks like mayonnaise in the sight glass. Okay, so I know I'm getting water in there somehow.

Does anyone have some suggestions on where the water is likely to be getting in? Where is the best place to start looking?

Another issue. Last night whilst riding home the bike started backfiring under engine braking at relatively low revs. On the way to work this morning it started backfiring again and intermittently not idling. Seemed to clear itself after a while. Should I be worried? It's getting about time for it's 5,000km service and I'm wondering if this is a sign that the exhaust valves are getting too loose.

regards,
MisterE

 

[Monty96CR]

i get condesation in the center of the sight glass between the metal and glass. More so when we have a really humid 90 degree day and i pull the bike out of the 75 degree garage. Short of a broken filler cap (or oring) and driving through water its highly unlikly to get water incursion in your bikes crank case. Water will froth in your oil not be mayonaise looking.

 

[jman900]

i get condesation in the center of the sight glass between the metal and glass. More so when we have a really humid 90 degree day and i pull the bike out of the 75 degree garage. Short of a broken filler cap (or oring) and driving through water its highly unlikly to get water incursion in your bikes crank case. Water will froth in your oil not be mayonaise looking.

I also have seen condensation on the oil sight glass. As for the backfire issue, it's lean on fuel. The carbs may need adjustment? Valves may need adjustment?

 

[Chuckracer]

How long is your commute?

 

[Deadguy]

the condensation or milky sight glass is normal

the backfiring is a fueling issue, probably need to clean out the pilot and main jets

 

[Mister E]

Thanks for the advice. I'll keep an eye on the sight glass and see how it goes. Time for the 5,000km oil change in any case so I'll have a good look at the oil once it comes out and go from there.

My mate thought water might be getting in through a poor seal around the rocker covers. He knows I opened them up for inspection relatively recently. Should I be worried? They look okay.

My commute is approximately 35km's one way. It's a mixture of twisties, open road and commuter hell down the motorway.

 

[CaribooBC]

If you had a poor seal around a rocker cover you would have an oil leak. I get the same condensation happening when riding in cool damp conditions. I was concerned at first as well, first thought was head gasket then I gave my head a shake and said "Air Cooled!!".

 

[DesmoDog]

Did you pull off a muffler recently? The backfiring you describe can be caused by an exhaust leak...

 

[jack]

Is it backfiring out the exhaust pipes or through the air filter?

Out the pipes is too rich. Back through the air filter is too lean.

Warm, humid air will condense when it come in contact with a colder surface, causing the "mayo" effect in your site glass. Your ride is long enough to evaporate the moisture in the oil. Do you only see it in the morning, or is it visible before you start it at any time of the day? I'm assuming you ride to work in the morning and ride home in the afternoon.

 

[Mister E]

There was an exhaust leak when I got the bike. This time it's definitely different. Sounds like it's coming out the pipes so too rich. It's coming in to winter here and it has been cold the last couple of days. It definitely seems to go better coming home than going to work in the morning. I'll keep an eye on it and see how it goes.

Good to know that the mayo I'm seeing is probably normal.

 

[Mister E]

Well, the bike was grumpier than ever this morning.

Started up first go as always. Kept it pretty low key going through the twisties near my house as there was a frost on the ground this morning. Got out to the straights and took her up to around 150 for a short spurt. Again, no worries. About 9k's done by now.

Then the problems. The bike just didn't sound right when trying to maintain a constant speed pretty much anywhere. When I tried to accelerate it would hesitate before accelerating and seemed well down on power unless I gave it a handful. Had to stop at a stop light and it just died.

It seemed to smooth out again near the end of the run to the point where the last stop light it actually idled okay (there are only two stop lights on my way to work).

My thoughts at the moment are that if this was valves I'd the issue to be more consistent than this. I'm leaning either towards issues with the spark as the bike warms up or fuel problems.

The problem does seem to be most noticeable when it is cold (less than 5 deg celsius).

Any more feedback from the collective wisdom? I'm planning on buying some new plugs on the way home tonight as I was going to replace them soon anyway. What plugs are recommended for a standard 900ss?

regards,
MisterE

 

[TassieDave]

Standard plug I used was NGK D8EA - something like A$5 each.

I recently decided to try Iridiums - NGK DPR8EIX-9. These are pre-gapped to about 0.9mm and the words on the box say "Do not adjust spark plug gap due to extremely fine electrode". Only need 2 so it wasn't too painful, cost about A$50.

Cold weather and standard Mikuni CV type carbs could be an icing issue. Moisture in the air freezes and causes the slides to stick. Some bikes delivered to cold regions were fitted with a carb heater kit - used warm oil to preheat the carbs. I bought FCRs and Dyna coils and the problem has pretty much disappeared. Expensive option though.

Another problem with the standard carbs is excessive wear in the emulsion tubes which might stuff up the mixture. I know nothing else about this one as I replaced my carbs.

 

[wdietz186]

Sounds like you have crap in the carbs.If the bike goes through fairly large temp changes you can have water form in the tank which will eventually wind up in the carbs.This can be an intermittant condition.If the quantity isn't too great high speed running can suck some of the non combustibles out of the float bowls and allow the pilot jets to meter fuel so it will idle again.I would try draining the tank and replacing the fuel filter and draining the float bowls and see if that doesn't clear up the problem.If it continues it will be time to get intimate with the carbs private parts.The pilot jets are tiny and can clog pretty easily.The milky oil is entirely normal,running long enough to get the oil over 200 degrees and/or partly covering the oil cooler in cold weather will help reduce the condition.Or get up earlier and take a longer way to work.

 

[Mister E]

Thought I'd send a quick update through on this issue.

Because I've been fairly pressed for time recently I decided to try different fuel. I switched to high octane first with the result of the bike running worse than ever.

Next step was to try a 10% ethanol mix. I'm glad to say that the bike is now much happier. I've since reverted back to my usual 91 octane and so far, so good.

My understanding is that ethanol tends to have a cleaning effect and that it will also absorb moisture like methanol does. I'm picking that the issue I was having was due to crap in the fuel line which is no longer there. Interested in getting people's feedback on whether or not this sounds right.

When I get some time I'll look at replacing the fuel filter in case its clogged and causing fuel starvation issues. Other then that I'll get the carbs looked at when I take it in.

Thanks for all your feedback on this.

regards,
MisterE