501 manifold rubbers
501 manifold rubbers
I have a 501 engined 3 1/2 which is a delight to ride, a real grin a minute bike BUT it has a problem which is starting to get me down, because it is still wearing the 3 1/2 airbox with the larger engine, the angle to said airbox from the carb is fairly extreme, although it seems to be achievable, the problem is that it splits the carb to head rubber manifold on a regular basis, not sure if it is not getting the support from the airbox that it should, although it seems solid enough. Yes, I am using the plastic collar on it. I have limped home on one cylinder once too often now and need a permanent cure. I am not sure if NLM's rubbers are as good as they could be. I am seriously thinking of going to pod type filters with some means of supporting them but NLM nearly faint when the idea is suggested, they certainly have not been able to suggest a better cure. What does the team think!!
Re: 501 manifold rubbers
A couple of years ago there was a post about new inlet rubbers. I purchased a set and they seem fine.
I still have Alessandro's email. alexluzzi@gmail.com
I payed via Paypal and received the inlet manifolds without issue. You may be able to find the topic via the search or just email him and see if any are still available. I can't remember the price.
Rod in Oz.
Found the topic:viewtopic.php?f=5&t=2294
I still have Alessandro's email. alexluzzi@gmail.com
I payed via Paypal and received the inlet manifolds without issue. You may be able to find the topic via the search or just email him and see if any are still available. I can't remember the price.
Rod in Oz.
Found the topic:viewtopic.php?f=5&t=2294
Re: 501 manifold rubbers
Pod filters can work ok if they're in reasonably still air and both see the same conditions. Many people have found it impossible to get vice free carburation with one filter sticking forward and one back.
Which type of carb to air box rubbers are you running, originals or the 'universal' replacements?
Which type of carb to air box rubbers are you running, originals or the 'universal' replacements?
Paul Compton
http://www.morini-mania.co.uk
http://www.youtube.com/user/EVguru
http://www.morini-mania.co.uk
http://www.youtube.com/user/EVguru
Re: 501 manifold rubbers
Is Alessandro from a company called "Start Gomma" in Italy? They might be my next port of call,
I've split 6 inlet rubbers in the 3 years, the last ones being fitted by NLM and lasting less than 200 miles, not funny.
None of the rubbers would be originals Paul, all NLM supplied replacements. Certainly not the same thickness of rubber as my 350 Strada'ish 3 1/2 which is wearing original rubber, (does that sound dodgy or is it just my mind)
Most 501 engined 3 1/2's that I've seen seem to use pod filters, it is tight to get to the airbox with the larger engine.
I've split 6 inlet rubbers in the 3 years, the last ones being fitted by NLM and lasting less than 200 miles, not funny.
None of the rubbers would be originals Paul, all NLM supplied replacements. Certainly not the same thickness of rubber as my 350 Strada'ish 3 1/2 which is wearing original rubber, (does that sound dodgy or is it just my mind)
Most 501 engined 3 1/2's that I've seen seem to use pod filters, it is tight to get to the airbox with the larger engine.
Re: 501 manifold rubbers
I have never purchased inlet rubbers from NLM so no idea on them. They can probably be repaired but if the material is weak then they may only break elsewhere.
How I fix mine: I thorougly clean the break with all purpose thinners and let dry. I use sikaflex auto sealant/adhesive. It is a polyurethane product and I leave the rubbers on the bench with a weight applying pressure. Leave it like that overnight but leave the join for at least a week. Forget what it says on the directions. I then use some RTV type silicone to smear on the inside of the manifold to protect the sika join from the fuel. I leave it another week. If you are really keen you can paint the outside of the manifold with the sika too. It helps to seal it and stops the rubber from hardening. The important thing about polyurethane is that it can be re-done. Virtually nothing sticks to set silicone but down the track if you need to re-do it the poly can be roughened up and re-coated.
i can't remember the name of the company Alessandro worked for but the name you listed doesn't sound familiar. I was just informing you he may have some and that my dealings with him were sound.
As for pods I have absolutely no idea what happens with the airflow between my knees and I'm quizzical of anyone who says they "know." I have a friend who burnt a hole in a piston running it WFO with a strong cross wind on pods tucked up under the tank on a 500S. Mixture? Ram air effect? Fat knees? Baggy pants? Who knows?
My last option is to go to a friendly auto store with a set of verniers and one of the inlet rubbers and go hunting through all the radiator hoses they have for one that has the required bend and internal diameter somewhere in its shape. Common cars are usually cheapest. Yes, yes I know it is water hose but you will be surprised how long it will last. New water hose will last longer than old brittle manifold hose. Here is another tip, don't worry about the step inside caused by the carby into the hose. You won't notice any difference. I've used this method a number of times and it has lasted for thousands and thousands of km's. If the inlet on the head is different to the outlet on the carby then just sleeve the part that is too wide to fit with yet another piece of radiator hose sika'd into the outer. Ramp and seal theleading edge with silicone. Curing times at least as above.
"You speak herecy" I hear you say, 'fluently' I reply.
Rod in Oz, not going to Morini heaven but planning on having fun on the outside track with like minded souls.
How I fix mine: I thorougly clean the break with all purpose thinners and let dry. I use sikaflex auto sealant/adhesive. It is a polyurethane product and I leave the rubbers on the bench with a weight applying pressure. Leave it like that overnight but leave the join for at least a week. Forget what it says on the directions. I then use some RTV type silicone to smear on the inside of the manifold to protect the sika join from the fuel. I leave it another week. If you are really keen you can paint the outside of the manifold with the sika too. It helps to seal it and stops the rubber from hardening. The important thing about polyurethane is that it can be re-done. Virtually nothing sticks to set silicone but down the track if you need to re-do it the poly can be roughened up and re-coated.
i can't remember the name of the company Alessandro worked for but the name you listed doesn't sound familiar. I was just informing you he may have some and that my dealings with him were sound.
As for pods I have absolutely no idea what happens with the airflow between my knees and I'm quizzical of anyone who says they "know." I have a friend who burnt a hole in a piston running it WFO with a strong cross wind on pods tucked up under the tank on a 500S. Mixture? Ram air effect? Fat knees? Baggy pants? Who knows?
My last option is to go to a friendly auto store with a set of verniers and one of the inlet rubbers and go hunting through all the radiator hoses they have for one that has the required bend and internal diameter somewhere in its shape. Common cars are usually cheapest. Yes, yes I know it is water hose but you will be surprised how long it will last. New water hose will last longer than old brittle manifold hose. Here is another tip, don't worry about the step inside caused by the carby into the hose. You won't notice any difference. I've used this method a number of times and it has lasted for thousands and thousands of km's. If the inlet on the head is different to the outlet on the carby then just sleeve the part that is too wide to fit with yet another piece of radiator hose sika'd into the outer. Ramp and seal theleading edge with silicone. Curing times at least as above.
"You speak herecy" I hear you say, 'fluently' I reply.
Rod in Oz, not going to Morini heaven but planning on having fun on the outside track with like minded souls.
Re: 501 manifold rubbers
Interesting - I was thinking of tucking the pods on my 350/501 in the airbox space under the tank - maybe that's not the best way to get them out of the airflow.
Alex Liuzzi is an independent; his father bought a vast amount of parts from Morini when they closed. I've bought things from him and he's very helpful.
Regards, Mark.
Alex Liuzzi is an independent; his father bought a vast amount of parts from Morini when they closed. I've bought things from him and he's very helpful.
Regards, Mark.
"I'll have a V please, Bob."
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'It must be a .....'
- Posts: 368
- Joined: 12 Sep 2010 12:25
Re: 501 manifold rubbers
Hi, OFF ROAD ONLY www.oro2u.com do loads of universal filters with straight/angle/elbow connector flanges and some have a cover over the pod filter. You could tuck these filters under the tank of a 500?
hope it helps, have fun.
hope it helps, have fun.
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harrymuffin
- Posts: 292
- Joined: 07 Apr 2014 16:06
- Location: west midlands
Re: 501 manifold rubbers
I also have a 507cc five speed in a 350 frame. The heads and barrels were new with the heads not having the inlet stubs fitted. Not liking this inlet set up, owing to the rubber inlets closing down in diameter in the bend, I chose to mount the carbs on solid inlets with the carbs but jointed and held with industrial hose so that the inlet was a uniform diameter of 28mm down to the valve where it closes down to effect a venturi and increase of gas velocity. The solid inlet stubs were made by threading a tube (fork stanchion is perfect 28i/d), screwing into the head till firm then obtaining thick walled 90deg section pipe 28i/d cut in half so that 45deg section was created, tack welding into the correct position on the stubs already in the head, removing and then welding up with another straight sect of stanchion in order to mount the carbs. Although solidly mounted the carbs still have a certain flexibility and of course not affected by heat from the head. I did intend to incorporate long velocity stacks but my left knee was just too close for comfort to the K & N in case of coming off. The K & N's took some time to be dilivered of the right dimensions and in my anxiuosness to test the bike I tried it with out filters and the only problem I encountered was it was impossible to go above about 30mph as the rear inlet was facing forward and thus the ram effect was causing the back cylinder carb to run rich and eight stroking (the float bowl is pressurized causing more fuel into the cylinder). I did fit a shield to the front filter but found it made no difference to carburation at what ever speed I run at. With this method the carbs can be located longitudinally and tuck under the tank. If you check the relevant port dimensions, especially the rubbers, then they are all over the place and as for the corrigated tubes from the air box it does nothing for volumetric efficiency. I have a conventional 496cc SEI with the original rubbers with again K & N's with no support and have had no problems with splitting, carburation or anything else, though I did fit shields to the filters to stop water running off the tank into the filters when left outside causing water in the float bowls. I did have one or two people bring their bikes to me with carburation problems and impossible to balance. On all occasions a split was found in the rubbers and the repair was to use cyanacrylate adhesive used for making 'O' rings which has rubber filler in the solution. Also, these inlets did not have the support collars fitted on the head side which need to be there to give support to the rubbers. Personally, as these inlet rubbers are no longer available to the original quality, then there are going to be problems in the not too distant future, and with one of you reporting failures at such short mileages from inferior (Chinese) reproductions, then you will have to take a couple with you whenever going for a run.
Re: 501 manifold rubbers
This is all really helpful stuff, thank you gents, still dithering over which way to go but this is all food for thought.
I think I will try some of Alex's manifolds first and see how that goes.
On a more positive note, I took the bike out at the Brands Hatch bemsee meeting Saturday, they do a lunchtime "parade," mine was the only road bike out there but overtook a lot more times than it was overtaken, great fun, they do handle well don't they.
Pete
I think I will try some of Alex's manifolds first and see how that goes.
On a more positive note, I took the bike out at the Brands Hatch bemsee meeting Saturday, they do a lunchtime "parade," mine was the only road bike out there but overtook a lot more times than it was overtaken, great fun, they do handle well don't they.
Pete
Re: 501 manifold rubbers
Pedro, you'd better come to Cadwell Park on July 4th, just to confirm your initial thoughts that they handle well!...
"I'll have a V please, Bob."
Re: 501 manifold rubbers
Take a look at the Brands parade photos at Racing Line Photography
www.racing-line-photography.com
BMCRC at Brands Hatch 5th / 6th April Saturday parade to see what it's all about,
Regs are now out for Brands long circuit 9-10th August
Come and have a run around Brands, you only need a road licence and it's FUN, Brooklands will be there with some oldies, the Velo club usually turn out and lots of varied old race bikes.
If I can keep my carbs on I will be there!!
www.racing-line-photography.com
BMCRC at Brands Hatch 5th / 6th April Saturday parade to see what it's all about,
Regs are now out for Brands long circuit 9-10th August
Come and have a run around Brands, you only need a road licence and it's FUN, Brooklands will be there with some oldies, the Velo club usually turn out and lots of varied old race bikes.
If I can keep my carbs on I will be there!!
Re: 501 manifold rubbers
Update on this issue, I sent the latest split ones back to NLM, Stuart was very concerned and immediately sent me out a pair of replacements F.O.C. Nice man and good customer service, I will be back.
However, in the mean time I had ordered some from Start Gomma, these arrived the same day as NLM's but appear to be made of much harder rubber, whereas NLM's are fairly soft and bendy, the Italian ones are much less so and more or less the same price. Only time will tell if they wear better but they do appear much stronger. Watch this space.
However, in the mean time I had ordered some from Start Gomma, these arrived the same day as NLM's but appear to be made of much harder rubber, whereas NLM's are fairly soft and bendy, the Italian ones are much less so and more or less the same price. Only time will tell if they wear better but they do appear much stronger. Watch this space.