Carb setup LM1

Checked timing, looks like RTBM, re the Gunson timing light. Stupid 60 degrees of advance would have been 30 ish plus the indicated, giving 90, which would be about right for t’other cylinder, I think. Being a Rita, both coils fire together every time.

Had a brief ride as I wanted to put fresh fuel in. Bike now starts easily, and is idling nicely, and pulling like a train above 3500, with possible pinking on left pot. Flat below, so difficult to pull away, needs a handful. Transition clearly not right & needs sorting, it’s surely carbs, not timing. I have not yet synched the carbs, so that’ll help. Didn’t get a chance to look at the plugs.

Then had to go for a walk to a local pub with Madame. She’s a hard task master.

Didn’t feel like doing any more today, watched French Moto GP. Good race.

Thanks to everyone who took an interest for your replies - it all helps.

Cheers
Simon
 
Sounds more like timing to me if it’s flat below 3500 rpm but running evenly. Are the throttle pumps working?
 
Thanks Chas,

Good question re the pumps. I wasn’t convinced last time I tried them. I expected a visible squirt when I twisted the throttle but didn’t check after the ride.

I was inclined to think it’s the carbs because giving it a handful is enough to make it pull fine, but thinking about it, I guess in doing so, I’m slipping the clutch to get rolling. Over advanced? Maybe the timing needs revisiting. :(

Cheers
Simon
 
The pumps make zero difference whether they are working or not IME.
 
Timing definitely wrong. Over advanced at fast idle and reaching full advance at around 3500 rather than 6500 revs. Crowsfoot spanners ordered.
 
This is just from memory, but isn't full advance around 4000? 6500 sounds very high.

I may well be mistaken.
 
I don’t know if it’s “MotoGuzzi” or “MotoGuzzi with Rita” but that’s what I read.

The spanners will arrive tomorrow & I’ll have a play. I suspect a bit more retarded will suit.

Thx
Simon
 
Does the Rita ignition still rely on the mechanical advance/retard (bob weights)?
 
Chas,

No, the Bob weights are removed, the “cam” is fixed directly to the distributor spindle. Advance is entirely electronic.

Atb
Simon
 
Sounds more like timing to me if it’s flat below 3500 rpm but running evenly. Are the throttle pumps working?

Chaz,

I had made a bollox of the timing. After much faffing, it’s now pretty good.

Thanks for your suggestion.
 
Postscript.

The noise would not go away. I took it to the local man, who agreed with me that there was something, but probably not bottom end, he thought it was the right, I thought it was the left. He was more wrong than I was.

The camchain was definitely flapping around. I decided to dig deep.

Pulled the cylinders off, and the left big end was definitely not right. Ripped to bits. Bizarrely all the other bearings are fine. Cleaned out the sludge trap, changed the camchain, added a spring banana tensioner, and am now rebuilding it.

More soon
Simon
 
after reading the last two pages i am never going to clean my guzzi`s carbs,:D it was running, then you decided to spoil it with a carb clean and now your down to big ends ? talk about a problem escalating, reminds me of the time i drilled a hole in the shower to mount a soap dish, the hole then started to leak water and ................................
looking forward to hearing that the rebuild went well, good luck.
 
Ha!

There’s a question. Coincidence or causality?

My guess is that the camchain and big end were totally bolloxed and I was polishing a turd hoping to fix stuff that was superficial…

Of course, it is possible, in an infinite multiverse, that me fixing the carbs screwed up everything else…
 


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