Topic: Yay, My 750K is running right again after a crazy storm. -Water in the tank,,,

[UnCrash]

Friday here in Portland Maine the heavens opened up and unleashed a flood amidst 80 mph winds.  This picture was taken along the road just a couple miles from my work...



The rain came down so hard you couldn't see out the windows at work.  It looked like you were in a carwash.

Of course I rode to work that day.

I went out after the storm passed and found the bike still upright.  I put the key in and turned it to on and pressed the start button and she fired right up and sounded normal so I happily walked back into work and finished my day.

It fired right up again when I was ready to head home.  Riding out of the parking lot I noticed that it was kind of bogging down.  From a stop it sounds fine, goose the throttle and it still sounds fine, get under-way and it doesn't have much power after 3K rpm.  Get on the gas hard while in gear and it sounds muffled and funny pull in the clutch and rev it and it sounds fine...

I chalked it up to the rain in some component someware.  If I were out there in that weather I know it would be inside my eyelids.

When I got home, about 5 miles, I check the pipes.  All were equally hot.  It idled just fine.  I put my hand over each one of the pipes at the end and noticed that #3 was irregular while the others were fine.  I pulled the airbox wondering if the filter were saturated.  There wasn't any water in the air filter.

So Today I take the bike out and find the same condition exists.  I rode for a couple miles on an errand and parked back in the garage.............................

I'll pull the plugs out and see what thier story is and check out the ignition.

For the record:
1976 CB750K (see my avatar)
Martek ignition
Stock coils
New spark plug boots
1 year old plugs
New carb insulator boots
Pulled the carbs and cleaned all jets 1 month ago when putting the boots on and she's been running excellent in general

[KB02]

Drain your float bowls and check to see if there is any water in them. If you do find water, drain the tank as well.

That's all that I can think of at the moment that you haven't checked already.

[MJL]

^^^ that's good advice.  I rode through a storm and somehow got water in the gas.

[neil10]

yes drain floats and  put  half cup methylated spirits in tank,  takes water out of system

[UnCrash]

Wow, never would have thought that water could get in the system... 

But now that you say that it seems like a real possibility.  The gas cap gasket is dry and cracked, could have also come in the vent hole, or any other breathing place...

That makes more sense than other possibilites.  I'll check into mentholated spirits, I'm not familliar with them. (sounds like an old-timey drink 

Thanks for the advice.

I'll add it to the list of things to check tonight.

Cheers,

Ben

[UnCrash]

Hehe!  I need a cup of coffee...

I read KB02's post as mentholated spirits instead of methylated spirits.

Interestingly enough, both are band names:

The Mentholated Spirits (http://profile.myspace.com/index.cfm?fuseaction=user.viewprofile&friendID=103230531)
The Methylated Spirits (http://www.indiscriminate.co.uk/clips/IDR011B_Mentholated_Spirits_-_Waiting_for_tonight_Flyin_&_Sparky_mix_CLIP.mp3)

Turns out KB02's methylated spirits are ----> http://adunk.ozehosting.com/metho.html

Methylated spirits ("metho") is a mixture of ethyl alcohol (95%) and methyl alcohol (%5). The methyl alcohol is poisonous and is added to prevent the methylated spirits being used as cheap drinking alcohol.

In the UK, Australia, and New Zealand, metho is called methylated spirits. In the US and Canada its called denatured alcohol, methyl hydrate*, or fondue fuel. In Europe, it may be called spirits, brennspirits (Germany), alcool a bruler (France), or alcool etilico denaturato (Italy). It is generally available in hardware stores, supermarkets, service stations, and camping/outdoors stores. Methylated spirits may not be available in some countries due to alcohol restrictions (e.g. Pakistan).

Thanks for the advice as always.  I have some Denatured Alcohol in the shop...

[UnCrash]

Ok,  I went home for lunch and spend some quality time with the bike.

I dropped the float bowls.  No discernable water in them.  I'm not sure what to look for, but it all looked like one liquid (gas).  One float bowl had a 1/4 inch long floating red something in there.  It seemed like a flexible acrylic paint chip or something.  I have no idea where that came from. It wasn't tank liner and I had the bowls off a month and a half ago on a clean workbench.  I must have missed something, or dropped this piece of thing in there...  dunno. (I hate when that happens)

I pulled plugs 3 and 4 both looked very reasonable (I ran out of time for 1 and 2).  They were on the cold/rich side of good but still within good running condition.

With only 1/4 of a tank of gas left I looked in and couldn't tell if there may be any water in there.  I poured my remaining half can of Seafoam in there because it says it helps to dry and stabilize gas. 

My Martek ignition looks fine, and the points gasket held up to the weather because it was totally dry in there.  The LED's which fire the ignition were clean and unobstructed.

Pulled the airbox and double checked that, all seemed good.

So, I put my helmet on and headed back to work on the bike.

The condition still exists, and here's the best description I can give of its symptoms....

Throttle response is normal when the bike is in neutral and the bike idles perfectly.  Crack the throttle in neutral and it sound good, even up at 5 to 6K... Like it wants to light the tires up.  Put it in first and throttle response/acceleration is normal for the first 1/4 of the throttle range.  After that it boggs down not unlike a lot of choke on a hot engine.
All remaining gears have slightly less response up to 5th where there is little throttle response and pre-detonation sounds when the throttle is really opened.  It coasts just like it should.

I rode the bike 5 miles into work and the condition did not change at all.

Does anyone have any thoughts?

My next steps are:

• pull #1 and #2 plugs for a look
• drain the remainder of my gas and try it in the lawn mower 
• remove the carbs, clean and blow out the jets

[andy750]

Ok long shot I know but....could water have got into the points and drenched a condensor? I rode through a heavy rain storm and some floods before and this is what got me - rain water in the points area (even though I had an electronic ignition -oh wait you have the martek -well Id still check for water in there.....


Worth a look...has to be ignition or fuel right?

good luck,
Andy

[heffay]

it is amazing where water can get...
we had a similar storm a couple of years ago and elizabeth's 98 vfr800 wouldn't even start afterward.
the vfr is even fuel injected so no carbs to sneak water in.

but, it ended up in the motor somehow, in the tank, in the injection system, basically, in everything.
needed an oil change, an injection system clean and new fuel and all was right.

[scondon]

 I'd take a second look at all electrical/ignition related components. Even new plug caps can get the resistors fried by riding in that kind of downpour. Water can cause arcing in all the wrong places and overheat components. Even when the water recedes/dries out there is a path that has been opened up for the current to go to all the wrong places.

[UnCrash]

I talked to a co-worker who's a SOHC veteran. 

Ignition is fine at idle but when the rpm's go up and under power (not in neutral) the bike boggs down.  Howard was curious if the ignition was properly advancing the timing.  We thought an easy way to test that would be to just turn the bike on and slowly turn the throttle from idle.  When advance is working properly you have the RPM's go up at a quicker rate when you hit advance around 2500 RPM.

I tested the throttle response just now and sure enough, at around 2500 the timing advance kicks in. 

So tonight I'll pull the mains and clean them out and see if that helps.  I'll also verify good spark through the throttle range with a plug pulled out.

Thanks for your input.

[UnCrash]

Well, the ride home was much better.

Seems that draining the float bowls, and adding the Seafoam have helped to identify fouled gas as the culprit. 

Response really picked up during my ride home and she's almost feeling back to normal.

I'll drain the rest of the tank and put fresh gas in and breathe a big sigh of relief.

I hope all my problems can be so easy to deal with.

Thanks as always for the input.

[andy750]

Good update Ben and glad its working itself out. Next time, get a cover for the bike for those heavy downpours ;-) Or better yet replace the gasket on the fuel tank cap (as I need to do as well!).

cheers
Andy

[heffay]

Good update Ben and glad its working itself out. Next time, get a cover for the bike for those heavy downpours ;-) Or better yet replace the gasket on the fuel tank cap (as I need to do as well!).

cheers
Andy

elizabeth's viffer was sitting in two feet of water.   

not high enough for the intake, but...

[UnCrash]

Good update Ben and glad its working itself out. Next time, get a cover for the bike for those heavy downpours ;-) Or better yet replace the gasket on the fuel tank cap (as I need to do as well!).

Z1 here I come! 

[KB02]

Hehe!  I need a cup of coffee...

I read KB02's post as mentholated spirits instead of methylated spirits.

Well, you're welcome. But it was actually Neil10 who suggested the spirits:

yes drain floats and  put  half cup methylated spirits in tank,  takes water out of system

I'm glad she's running better for you.