Another oddity... plugs got fowled, for no reason?

[tc80211]

Hey Guys,

'83 R65
No changes to carbs were made. just hadn't ridden in 3-4 weeks and was sitting on side stand. I started the bike with choke and let it warm up. Rode away and then noticed power loss, then back to normal. Did this a few times before being at a stop light and it cut completely regardless of how much throttle i was giving it to keep it on. Then won't start. Let it sit for 4-5 minutes and only starts with wide open throttle and then repeat what was stated prior, enough to get home before it died again.

Checked the plugs and both are fowled. Very black.

Changed plugs, bike fires right up. But when engine is running I am noticing the exhaust is more of a "pop" sound. Very odd, could it just be time to clean the carbs again?

I have attached a video that provides the exact sound I speak of.

[Bob_Roller]

I'm just thinking out loud here !!!!!
You said you left the bike on the side stand, for close to a month .
Don't do that .
You may want to check to see if the carb floats have become stuck, or hung up, allowing too much fuel in the float bowls .
Was the fuel tap left on as well during the time the bike was idle

[SoloLobo]

Leaving the bike on the side stand will have oil by-pass the low side piston rings and can account for one side's fouling (perhaps)

The popping after plug change means there is another issue.  I am going to say it is time to strip and clean your carbs... perhaps time for a new airfilter as well

[tc80211]

I'm just thinking out loud here !!!!!
You said you left the bike on the side stand, for close to a month .
Don't do that .
You may want to check to see if the carb floats have become stuck, or hung up, allowing too much fuel in the float bowls .
Was the fuel tap left on as well during the time the bike was idle

Fuel tap left in ON position yes. I did check both floats and both seems to be fine. Carbs were rebuilt just over a year ago.

[Barry]

The side stand won't have helped and warming up on the choke will carbon up the plugs in short order. Parking on the centre stand with the fuel off and minimizing use of the choke should keep the plugs clean.

One thing that has been demonstrated by recent threads is that the amount of choke needed varies dramatically between bikes but one thing that all airhead guru's will recommend is you use the minimum amount of choke consistent with the engine running properly and ride off as soon as possible ideally with the choke off if it will run cleanly. Inability to idle in the first few miles is not a reason to use the choke if the engine otherwise runs ok.  The potential problem from excessive use of the choke is not just carboned up plugs but engine wear as the excess fuel washes oil off the cylinder bore and dilutes the engine oil.

[tc80211]

The side stand won't have helped and warming up on the choke will carbon up the plugs in short order. Parking on the centre stand with the fuel off and minimizing use of the choke should keep the plugs clean.

One thing that has been demonstrated by recent threads is that the amount of choke needed varies dramatically between bikes but one thing that all airhead guru's will recommend is you use the minimum amount of choke consistent with the engine running properly and ride off as soon as possible ideally with the choke off if it will run cleanly. Inability to idle in the first few miles is not a reason to use the choke if the engine otherwise runs ok.  The potential problem from excessive use of the choke is not just carboned up plugs but engine wear as the excess fuel washes oil off the cylinder bore and dilutes the engine oil.

Thanks for the info! Hoping to spend some more time tonight with it.

[Bob_Roller]

Is the choke stuck in the on position ?

[tc80211]

Is the choke stuck in the on position ?

Choke is good and in off position... going to go ahead and take the carbs apart and clean them this weekend.

[Bob_Roller]

If both spark plugs are fouled, a carb problem on both cylinders probably not real likely .

After going through the carbs ,if things have not improved, check the ignition system .

Do you have an original gray and black ignition coil

[montmil]

First thing I thought of when you mention fowled spark plugs was that your engine had swallowed a bird and feathers were clogging the carbs. However, fouled plugs are likely a result of the above noted 'Airhead Sins":

1) Leaving the fuel petcock in the on position.
2) Parking the bike on the centersatnd for lengthy periods with the petcock open.

Both invite trouble. Several forum members hereabouts even go so far as to turn off the fuel about one-half mile from home. I now do this out of habit.

I would even go so far as to suggest you change the engine oil as it could be diluted with gasoline and is now not doing a proper job of lubricating the engine. If that is allowed to remain, fouled plugs could end up being the least of your concerns.  

[tc80211]

First thing I thought of when you mention fowled spark plugs was that your engine had swallowed a bird and feathers were clogging the carbs. However, fouled plugs are likely a result of the above noted 'Airhead Sins":

1) Leaving the fuel petcock in the on position.
2) Parking the bike on the centersatnd for lengthy periods with the petcock open.

Both invite trouble. Several forum members hereabouts even go so far as to turn off the fuel about one-half mile from home. I now do this out of habit.

I would even go so far as to suggest you change the engine oil as it could be diluted with gasoline and is now not doing a proper job of lubricating the engine. If that is allowed to remain, fouled plugs could end up being the least of your concerns.  

Thanks Monty! Oil change sounds like cheap insurance, will absolutely do that too. Took one carb off today and started sorting through it, definitely gummed up.

[montmil]

Thanks Monty! Oil change sounds like cheap insurance, will absolutely do that too. Took one carb off today and started sorting through it, definitely gummed up.

One carb disassembly at a time is a wise procedure for all of us. The carbs are "handed"; meaning there are some parts that fit only the right or left carb. Mixups can happen.

Some parts are better replaced than attempting to clean and reuse. For example, the needle jet is a wee bit 'wobbly' when properly installed in the slide. The needle jet, depending on mileage and use, can become worn by the needle's constant movement. You then could have problems getting mid-range operations to your satisfaction. Rubber o-rings and gaskets are cheap. A light smear of plumbers silicone grease, dielectric grease or even Vaseline aids o-ring install and does a good job of preventing tears.

Carb diaphragms may have unseen microscopic holes. A full carb overhauls should include these vital rubber parts.

Here's a helful link on Bing CV carb overhaul:
http://www.gunsmoke.com/motorcycling/r100gs/carb_rebuild/

[tunnelrider]

Good tip Barry about no excuse to ride off with the choke half on, 'cause too much will dilute the oils and seals.

I have to admit I've used it to keep the bike idling OK for the first few mins if I have stop lights, usually when below 15 deg. C (59 deg F).

But it's hard to let an R65 idle at 5.30am for a full warm up without thinking of the neighbours!

I guess I got my lazy tendencies from the Owners' Handbook I think, says it's OK for a few miles at the half notch.  It also means I'm usually short of time and just wait the initial period at full choke to change pitch and rhythm before riding off.  A bit bad perhaps.



Makes sense it might dilute the oils with looser tolerances of an older bike.