1982 R65LS: rehab bumps - no start

[opus451]

Hey All,

Hope everyone is healthy, happy.
Riding often.

Here is the problem: Bike turns over, catches for a second, enough that the starter squeals to leave it alone, but then just doesn't catch all the way. Stalls after the first chug or two.

What I have done thusfar:

New battery.
New gas with a bit of seafoam added.
New gas lines, inline filter.

So in a previous post, I shared the float bowls of death.
They in the end after a good cleaning were so pitted they developed holes and leaked pretty good.
Which ruled out bad petcock and bad float needle, but not so quickly (or rather my brain did not quickly compute) that i did not inspected both, and petcock could use a rebuild kit although filter seems fine, and needle rubber looks good, and cleaned the needle seat out. For now going to assume floats are still within spec. So float bowls replaced. Carbs broken down, inspected, cleaned, and rebuilt with gaskets and rings. Diaphragms look fine.

Cables adjusted according to manual, mixture screw set to default until carbs are synched if I ever get the damn thing running long enough.

I cleaned out the gas tank, plenty of rust flakes came loose. Went the naval jelly/krud kutter mixture route to retard rust on the inside and coat it for now until winter.

There is spark at the plugs.

I am assuming for now that valve clearance is normal and timing correct. The bike was supposedly running before it was put on the kick stand and left to rot for years.

Looked over the front electrics compartment, and no corrosion really.

Any thoughts or ideas?


Much appreciated!

Opus from Brooklyn

[SteveD]

Timing and valves are worth checking, especially valves as it's easy to do and only a 15 minute job.

When you say "default" what are those settings? As per the BING book, 335 & 336 carbs (65LS) should have the needle on the 3rd position (reasonably rich) and the idle mixture screw @ 0.5 turn out from closed.

Other simple things to check.
1. the small jet in the carb bowl...is it blocked? I guess they're new with the new bowls?
2. does fuel flow from the petcocks at a reasonable rate?
3. I wouldn't presume anything about those floats. Their colour was "past it", imho. What is the fuel level in the bowls?

Starting technique. Incorrect technique can flood the bike. From cold...
1. Ignition on
2. Full choke
3. Freeplay in throttle taken up, but not "opened".
4. Depress ignition button, and when the engine catches, open the throttle enough to keep the engine running.

Apologies if these are already known, tried and tested.

[montmil]

Here's a photo of opening for the small "jet" that feeds the enrichener circuit. If the jet is clogged, and that is a possibility with the debris you mention, the enricheners will have no fuel to do their job. Strip out a single strand of thin copper wire and probe the jet. Test by adding fuel to the float bowl reservoir and confirm fuel is passing into the smaller reservoir. Check both float bowls.

[khittner1]

Opus---With carb float bowls that looked as bad as yours, you probably ought to give up hope for cleaning as a remedy, and find a new/used functional set of carbs. You should probably pull the heads off to see what got into the combustion chambers. Compression testing is certainly in order if you haven't checked that yet.

[opus451]

Thank you all for the advice!

Float bowls are new but will check the enrichener jet to make sure. That was the other reason for new bowls beside the pit holes. That jet was useless.

Curious, can the floats for the bing slide carb be used for the cv? I have a pair from my 60. Trying to go easy on the bank. Ones in there are on the brown side. Don't have a scale to weigh them but safe to assume they can be retired.

Thanks for those techniques Steve! We all could use a lil fine tuning.

And KH, my thought exactly-next is compression test, followed by a valve clearance check, and in the end checking the timing when all else seems ready.

Much appreciated Guys!
Will update.

Opus

[Kurt in S.A.]

You can test floats by putting them in a jar/glass of gas. If about 1/3 is above the surface, they're fine. Also, you set the float such that when the gas shuts off, the seam on the float is parallel with the body of the carb. You can confirm the setting, by letting the bowl fill with gas and then shutting off the petcock. Drop the bowl...is the height of fuel in the bowl around 22-24mm? If so, then the float is fine.

Kurt in S.A.

[Bamboo812]

Adjust the valves BEFORE doing a compression test...

[Major Softie]

Adjust the valves BEFORE doing a compression test...

Yes. Clearances way off could give you a bad compression reading - especially if you've got one closed up.

[Duane Ausherman]

OMG, the FIRST thing to do is add a few drops of fuel directly into the spark plug hole, as it sounds like it is lean to me. Always, always start with the simple and proceed to the complicated.

[khittner1]

The major engine health checks are in order, given the cancerous condition of his carbs. I guess we know that the bores aren't seized (anymore, at least), since it has apparently turned over, but internal engine corrosion wouldn't be surprising.