Excalibur Peculiarities

[swtuggle]

Just joined, first post. Finally bought my very own Morini, a '87 Excalibur 501. Spent all of its life in Pennsylvania and Virginia, but now it's been delivered out to the Puget Sound region of Washington state. Over the weekend, I was looking it over, getting familiar with the Morini way, I noticed a few things.

First, the shaft of the oil dipstick is curved, apparently to facilitate removal underneath the rear exhaust pipe as it snakes around the right side. It's clever, but is it correct for the Excal? I'd hate to service oil to the marks, only to find I overserviced the crankcase.

Second, it has PHBH30ES carbs (which will need an overhaul), whereas everything I've read lists PHBH26 for the Excalibur 501.

Third, everything I've read about the Excalibur says it should have a Kokusan alternator, but this one has the Ducati Elletrotechnica magneto attached to the electric start drum.

Looking forward to some good exchanges with fellow Italiaphiles!

Regards,
Steve

[mgill]

Hey I saw this bike on I-80 between Cleveland and Toledo, OH two weeks ago.
Doing about 75mph in the back of a pick up truck....
Looked brand new.
Nice price on e-bay too, was tempted to buy it and put the motor in my race bike.
Regards,
Mathew Gill
Canada

(small world eh?)

[EVguru]

The dipstick is curved so it clears the gear cluster when it is installed at the only angle the exhaust allows.

Oil capacity is 2.5 Litres (10w40 semi synthetic), so you can use that to check your dipstick calibration.

PHBH30ES carbs are US emission spec. They're jetted very lean and then use an accelerator pump to compensate. They're really too big and the setup doesn't have a good reputation. The 500 engines started off with PHBH26 carbs, with later 501 RLX Excalibers being fitted with PHBH28 carbs and you're probably better off replaceing the carbs.

Later Excalibers did have Kukusan ignition (for certain the RLX versions) and front mounted starter, but earlier ones didn't.

[swtuggle]

Small world, indeed, Matthew. Was the pickup driving on the road or on a car trailer? The bike does look quite nice for a 1987. Up close and personal you can see it's not mint, which is what I expected, so no surprise there.

Paul, thanks for the info. Since the PHBH30s have shortcomings as delivered, can I rejet or do anything to improve the stock carbs since I have them apart and plan to overhaul them? I also plan to remove the stock airbox and run conical filters to free up some airflow.

One of the first things I did was pull the right cover to inspect the timing belt. Oh yeah, pretty loose. Silk screening says Moto Morini, so I'd bet it's original. Got two Mitsuboshi belts on order. The cam pulley is stamped B, so I hope the Mitsu fits well.

I'd like to find a L5 cam for an eventual upgrade, or is it not worth the effort?

Should I leave the stock exhaust plumbing alone? I can only hope that the engineers designed that reverse-flowing horseshoe-shaped "balance tube" located under the crankcase for cylinder scavenging reasons.

Regards,
Steve

[EVguru]

Since the PHBH30s have shortcomings as delivered, can I rejet or do anything to improve the stock carbs since I have them apart and plan to overhaul them? I also plan to remove the stock airbox and run conical filters to free up some airflow.

I doubt you're getting anywhere near the flow capability of the airbox. It's very similar to the one on a Dart and there is a restrictive sleeve over the filter and some other bits in there that can be removed. Pictures on my website; http://www.compton.vispa.com/morini/dartmods.htm

On the carb side of things, I'd sign up to the Morini emal list as the same carbs were used on US spec Camels and there are some people with experience of sorting the bikes. In most cases it's an upgrade to a smaller non-pumper carb as I recall.

I'd like to find a L5 cam for an eventual upgrade, or is it not worth the effort?

Are you planning to race it? I think you'll find it goes pretty well with the stock cam!

Should I leave the stock exhaust plumbing alone? I can only hope that the engineers designed that reverse-flowing horseshoe-shaped "balance tube" located under the crankcase for cylinder scavenging reasons.

So Lambertini claimed and Alex at NLM certainly thought it made a significant improvement to his 350/500 hybrid track day bike. It's an awkward set of bends comprimised by styling and Alex built a replacement system with better ground clearance. That's unlikely to be a problem on the Excalibur.

[swtuggle]

Are you planning to race it? I think you'll find it goes pretty well with the stock cam!

No plans on racing it, just looking into the future in case I employ this motor in a Sport or Strada.

Another thing that doesn't look very obvious is how to remove the Ducati alternator "magneto" flywheel, so I can replace the timing belt. I haven't been able to remove the nut yet, but when I do, are there threaded holes to facilitate the use of a puller?

[EVguru]

Recent timing belt discussion;

viewtopic.php?f=4&t=1483&p=6976&hilit=timing+belt#p6976

There are several wright-ups of the job out there.

Here's one; http://blog.morini-riders-club.com/blog ... 31506.html

If your pulleys are rusty like that I'd be inclined to run the engine for a few minutes to remove most of the rust before changing the belt. Taking them off to clean is the best way, but you have to be confident about getting the timing right again afterwards.

[swtuggle]

Thanks for the links. Guess I could have done a search before asking about something already covered ad nauseum.

Great idea about modding the stock airbox. Does your Dart moan or honk loudly upon acceleration now that the restrictions are removed? I figure it can't be as loud as open element filters.

[EVguru]

I don't think the intake mods made much difference to the noise. Along with the straight through exhaust It definitely improved the top end performance. The exhaust wasn't much louder than stock, but it was a much nicer noise.

[swtuggle]

I see in another post, you stated a 27x1.25 puller is required. I saw in another post, a person stated to use a 26x1.5 thread. Being that close, I'll bet anyone experiencing a stripped flywheel was caused by trying to use 26x1.5 puller.
Before I order a 27x1.25, I want to confirm that Morini used only the one size, or did they machine different sizes for different years/models?

[mgill]

Only one size. NLM or Hermy will send you one

[swtuggle]

I've decided to simply replace the ES carbs, but not sure which would provide better overall performance, PHBH 26 or PHBH 28. Suggestions?

[EVguru]

The 28mm versions seem to run just fine with good tractability, so I'd be inclined to go to them. If you ever tuned the engine in future, the carbs wouldn't be the limiting factor.

[72degrees]

I run 28mm PHBH on my 375 with L5 cam. Still chasing a slight flat spot in the mid range. Not helped by several recent changes to the 2:1 exhaust which had to be repaired and so i repacked the 'silencer'. One day I'll try trick atomisers or whatever. A bit better since I dug the Morgan mercury manometer out after having to swap the front head but not perfect. OK if you just give it the beans though

[swtuggle]

Didn't see any definitive answers applicable to the 507 from using the search feature, so bear with me if this is an old question. I'm ready to purchase a pair of PHBH28BS carbs, but wonder if I should purchase some additional jets at the same time to fine tune them. I was told the as-delivered specs are as follows:
105 main jets (wasn't given the main needle #)
65 pilot/idle jets
70 starter/choke jets
40 slide
200 seat/#2 needle.

The Dellorto direct rep isn't familiar with Morinis, and when I told him what the original 30ES emissions carb specs were, he thought I should purchase a couple smaller sizes of main jets. I informed him of what Paul told me, that the ES were jetted lean, and never ran well. Additionally, I have performed the airbox mods Paul illustrated on his site.

So I ask the subject matter experts, should I try some 110 or 115 mains & any others for that matter?