General My 5ino's transatlantic adventure
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General My 5ino's transatlantic adventure
the hobbler
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yes, sump bolts are 6mmx 1.00mm x 1.00inch. Have you tried using a longer bolt? just in case it is only the 1st section of thread that is knackered. I always use stainless 'cap-head' (allen key) bolts. I would never recommend that the cork gasket is used, you cannot get the bolts tightened correctly as the cork just keeps on compressing. If you do want to use a gasket, always use the 'ruberoid' variety. Having said that, more and more people seem to prefer using one of the modern sealants instead of a gasket.
I had one bolt on mine that had also been botched, but the responsible engine rebuilder had tapped the hole in the block out to 8mm. So I have all 6 mm bolts except one. I used Permatex Ultra Grey RTV and no gasket and I have no leaks. Installing the pan is a little fiddly; be sure to do it up very gradually and evenly in a crisscross manner. And don’t cross thread the bolts!
Before installing, be sure to inspect the drain plug and make sure it has a washer. I used a fiber type but others have used copper or aluminum crush washers. I also used a thread sealer; some have used Teflon tape.
Before installing, be sure to inspect the drain plug and make sure it has a washer. I used a fiber type but others have used copper or aluminum crush washers. I also used a thread sealer; some have used Teflon tape.
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turbo500
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Hi everyone, been away from the forums as life has been busy. Poor 500 has been sitting with the damaged hood. I decided this weekend, to pull the carb, as last time I drove it, the engine kept cutting out when accelerating. I'm hoping it's fuel contamination.
Anyhow, I pulled the carb, here are the pics:
Nice sediment buildup from the fuel...
I've done a little bit of cleaning, will probably end up hitting it with a brush and some fuel.
I have a set of gaskets+orings+etc, as well as a new float and pin just in case. I tested the float, by submerging it in water, but it still sounds empty inside, so at least I don't need to replace it.
Is there anything from the photos that I should take a look at? I haven't tried removing the choke valve. How do I remove this? It looks different from Chris (bambino) thread about IMB26 teardown
Also looks like the venturi took quite beating for some reason...
Anyhow, I pulled the carb, here are the pics:
Nice sediment buildup from the fuel...
I've done a little bit of cleaning, will probably end up hitting it with a brush and some fuel.
I have a set of gaskets+orings+etc, as well as a new float and pin just in case. I tested the float, by submerging it in water, but it still sounds empty inside, so at least I don't need to replace it.
Is there anything from the photos that I should take a look at? I haven't tried removing the choke valve. How do I remove this? It looks different from Chris (bambino) thread about IMB26 teardown
Also looks like the venturi took quite beating for some reason...
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turbo500
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Hello again,
It's been a few years. Finally getting round to working on my 500 again!
I am currently trying to figure out what to do with the carb. Before putting her away, I dismantled the carb and tried to service it, only to realize it was bent in multiple places, and I'm not sure it's even worth trying to fix.
So I was going to buy a new 26IMB, but then remembered that I have a 126 head (not sure about the internals or bottom end). Should I still buy a 26IMB, or get the 28IMB?
Also, when replacing a fuel pump, is it pretty much just a straight swap? I have a new BCD pump from Italy I want to install.
Thank you
It's been a few years. Finally getting round to working on my 500 again!
I am currently trying to figure out what to do with the carb. Before putting her away, I dismantled the carb and tried to service it, only to realize it was bent in multiple places, and I'm not sure it's even worth trying to fix.
So I was going to buy a new 26IMB, but then remembered that I have a 126 head (not sure about the internals or bottom end). Should I still buy a 26IMB, or get the 28IMB?
Also, when replacing a fuel pump, is it pretty much just a straight swap? I have a new BCD pump from Italy I want to install.
Thank you
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turbo500
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No clue about the engine. I've attached some pics. Is there anyway to figure out what it is from these?
Dynamo, so I believe the BCD pump should be a straight swap (I have a new bakelite spacer).
Yes the engine is for a 500F or L. How big is the inlet port under that Bakelite spacer. If it is 26mm diameter then you have a 500 head. If it is 30mm then you have a 126 head.
with an alternator you would need a fuel pump with an angled face But you will be ok with a Dynamo.
with an alternator you would need a fuel pump with an angled face But you will be ok with a Dynamo.
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turbo500
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Yes the head is a 650 because it has the cross hatched cooling design and also it says 126 on it. I want to understand if it's only the head or the rest of the internals as well, so that I can figure out if I need to get a new 28imb or stick with the 26imb
Need a new gasket as well
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turbo500
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So do you know what the correct part number for the carb spacer if I want to get a new imb26?
Would like to avoid ordering the wrong parts :s
the hobbler
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Just to throw a complete spanner in the works---yes, it is a 500 crankcase, but has it got enlarged barrels; the 500 crankcase can take up to 652cc barrels. If it has a '650' head, I would be tempted to fit a 126 652cc spacer and, if obtainable, a 28IMB carb---won't do it any harm, and might just helpthe performance a bit.
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turbo500
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Oh no, don't tell me that
How plug and play is the 28IMB? I think I would need a new elbow, spacer, anything else? Is the performance worth it?
(I need to buy a new unit since no one around here sells refurbs so it's either a new 26IMB or 28IMB)
My thoughts re carbs are it does not matter is you have the original 499ccs or a 650ccs upgrade , which I doubt, you can fit whatever carb you like. The original 26IMB carb has its faults including some parts warping or bending but they can be sorted for those that insist on originality. They improved the carb as they went and the 26IMB 10 which was fitted to the 500L being the last and most robust. Having said that you have a 126 head so it seems sensible to capitalise on that and any possible gains by going for a 28IMB carb. So you would need base gasket for spacer, new spacer if you want to replace that chipped one, carb base gasket as the one you have fitted is a 26IMB top inlet gasket if I am not mistaken, top inlet gasket and inlet elbow which should join up to your existing air filter. Some thing like this -
you would need to blank off the fuel return return outlet unless you want to install a return pipe to the tank.
so where would you source your parts from if you can get them?
the internet has been awash with ”new” IMB carbs which fall into two categories. Made under license Weber carbs which have mixed reports and unbranded Chinese fakes that have had bad reports.
you would need to blank off the fuel return return outlet unless you want to install a return pipe to the tank.
so where would you source your parts from if you can get them?
the internet has been awash with ”new” IMB carbs which fall into two categories. Made under license Weber carbs which have mixed reports and unbranded Chinese fakes that have had bad reports.
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turbo500
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Hey, I know I’m torn about the switch. I found someone in the US who is a Weber carb specialist, so I wouldn’t be worried about it being a knockoff.
I’m trying to figure out if the brass bolt where the fuel spigots are is included or not because I keep seeing pics of the carb for sale without it.
Also, do you know if everything else would work like bolts, throttle arm etc?
Also, when it comes time to regulate the carb, I’m guessing I should just follow standard procedures like I would with the 26imb?
Thanks for your help!
The carb You are looking at there will be a Spanish made under licence Weber. The missing brass cap and carb internal filter is a dead give away. Not necessarily a bad carb. I bought a collection of spares from a retiring 500 specialist purely because it included one of those carbs and I wanted to pull it apart to see what all the fuss was about with reports of dodgy carbs. Having restored many of these carbs I am pretty much up on what to look for. I pulled it apart for inspection and found nothing untoward. The carb was sold to a guy in the week before his wedding when he wanted to use the 500 as his wedding car After a sudden carb problem. All went well 
I was left thinking that the problem carbs would be the fake unbranded Chinese made ones. I have yet to examine one of those but from the pictures I can see that the castings look poor quality.
I was left thinking that the problem carbs would be the fake unbranded Chinese made ones. I have yet to examine one of those but from the pictures I can see that the castings look poor quality.
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turbo500
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So basically the newer production carbs dont have the brass cap on top (the filter is gone correct?). So I can reuse all the same hardware for mounting it as the 26IMB including the throttle arm?The carb You are looking at there will be a Spanish made under licence Weber. The missing brass cap and carb internal filter is a dead give away. Not necessarily a bad carb. I bought a collection of spares from a retiring 500 specialist purely because it included one of those carbs and I wanted to pull it apart to see what all the fuss was about with reports of dodgy carbs. Having restored many of these carbs I am pretty much up on what to look for. I pulled it apart for inspection and found nothing untoward. The carb was sold to a guy in the week before his wedding when he wanted to use the 500 as his wedding car After a sudden carb problem. All went well
I was left thinking that the problem carbs would be the fake unbranded Chinese made ones. I have yet to examine one of those but from the pictures I can see that the castings look poor quality.
I think if I can get the elbow/spacer/etc easily I will probably go for the 28IMB...
If you have problems I can supply an elbow and gasket set from here in the UK. I also have one last refurbished original Weber 28IMB carb. I have shipped a lot of parts to the US including carbs. We can ship airmail to the US for around £30
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turbo500
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thanks. Let me see what I can find.
Can I reuse the stud bolts from the 26imb or do I need new ones?!
Is there a parts number for the bolts?
The flange on the 28IMB is thicker on one side so you need a slightly longer stud nearest to the rocker cover. They do not have part numbers.
I have repaired a couple of Bakelite spacers recently where they have been chipped by forming a sort of mould with masking tape and using JB Weld then dressing it up when it has set hard.
