It's just not right....

Re5Guy said:
Just an update everyone, I've been away for the last 2 months plus so just back into it now...
I have changed the pilots to 55s, replaced the choke plungers and the pesky short spring mentioned earlier. It is now better but still definitely not right.
I can now get some change in engine speed playing with the fuel mixture screws but the bike is still rough between idle and 2,000rpm.
It will now pop and backfire on the over run when slowing down (which it didn't do before the changes above) and it just feels unhappy. Get to 2,000rpm and all is well.
I have looked for air leaks where ever I can think to look and tightened everything up. The only thing I haven't done yet is remove the inlet manifolds and double check them for any cracks/leaks...hopefully this weekend.
It still starts and idles well after it's warmed up.

This is all part of the "FUN"...right? :LOL:
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If you can keep a RE5 on the road , then I`m sure you`ll get the RGS sorted eventually ......... :) ............
 
Rob said:
A quick way of checking for inlet manifold leaks is to spray some carb cleaner on them in turn. Engine speed will change
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Very good idea Rob, but I already took them off and I reckon I've found the issue.
There is an O ring in the front of the manifolds to seal them to the head. Mine are obviously very firetrucked. They are sitting lower than the edge of the manifold and are hard as rock.
Replacements ordered and fingers crossed.
cheers all.
Tony
 
I thought I was doing the right thing by getting Vitron O-rings that are fuel-resistant, but they were a bit too thick, and I snapped one ear off; it didn't take much.
 
Andy said:
and warp, if the o-rings are too fat
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The " ears " on my 1200 Mirage I found to be warped , on inspection ....... although I didn`t have any particular problems as a result of that ....... If anything it was the insulation gasket between the manifold and head which became deformed first , causing the ears to warp when the manifold nuts were being tightened .......

I think this may have applied to a spare head I fitted for a while , whilst the original head was being refreshed ....... I`m pretty certain the manifold set up on my original head was never disturbed .... ( no need ) .........

The set up was ....... carb > manifold > o-ring > insulation gasket > o-ring > cylinder head ..........

Alan Bell of Miura Engineering here in the UK sold what he described as strengthened manifolds , which I fitted ....... but really the thing was to inspect the insulation gaskets in the first place ....... and make sure the o-rings are the correct size , as you say ......... and replace those insulation gaskets if they show any signs of distress , before re-fitting the manifolds .........

Can`t really remember how all this originally came to light .......... after all , removing and replacing inlet manifolds is hardly the sort of thing you`d do every other weekend ........

So I`m thinking it must have applied whilst sorting out the used spare head I fitted , as mentioned earlier ....... which was also obtained from Alan Bell , by the way ....... quick decoke of chambers and valve faces , cams in with appropriate shims , bolt it on ......... and fine for the next 20,000 miles , until I decided to refit the original refreshed one ........... The only thing to be careful of was making sure you fitted the correct length cam follower buckets ....... You don`t want longer ones in a head which has been running the shorter ones .......

Life was so much simpler back then ......... :) ................



BTW ....... all this applies to the 1200 I had ......... it sounds like the new fangled RGS has a different inlet manifold set up ..........
 
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rocketonarail said:
The " ears " on my 1200 Mirage I found to be warped , on inspection ....... although I didn`t have any particular problems as a result of that ....... If anything it was the insulation gasket between the manifold and head which became deformed first , causing the ears to warp when the manifold nuts were being tightened .......
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They all do that... :rolleyes:

The insulator compresses under excessive torque, bending the manifold "ears" in the process.

I've come across very, very few that were not warped/bent/snapped. Up to 0.5mm deformation is quite common. Not too dramatic, a quick clean up on the lathe restores reliable sealing. The "ears" may then no longer be parallel to the mating surface, but in practice, it all works out nicely, provided new flat insulators and correct o-rings are fitted.

piet
 
sfcpiet said:
They all do that... :rolleyes:

The insulator compresses under excessive torque, bending the manifold "ears" in the process.

I've come across very, very few that were not warped/bent/snapped. Up to 0.5mm deformation is quite common. Not too dramatic, a quick clean up on the lathe restores reliable sealing. The "ears" may then no longer be parallel to the mating surface, but in practice, it all works out nicely, provided new flat insulators and correct o-rings are fitted.

piet
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Sorry Piet ........ may have edited my post again since your reply ...... ( I have a habit of re-reading several times after posting and amending before being happy with a finished version ) ......... I`m always thinking of things to add afterwards .........

Don`t think it`s affected your reply though ........ :) ...........

Tony
 
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Ok, update time...and it's not good news, new o-ring gaskets carefully fitted and it made no difference. I checked their sealing with the carb-clean tip Rob suggested and idle speed did not change, so I think that can be crossed off as a possible source of the trouble.

To re-cap. The bike runs unhappily between idle and 2,000rpm after which it is quite happy.

When I start it up cold it starts easily, but it feels and sounds rough. As I turn the choke off it starts to pop and backfire. If I turn the choke back on half way the misbehaving stops but it still feels and sounds off. As it warms up the backfiring stops but again it still feels rough and unhappy. Riding it off idle is unpleasant as it isn't smooth at all. Playing with the air screws makes no significant difference.

Any new words of wisdom?
 
If timing is not correct, the mixture screws will not any or no effect. Considering the amount of work carried out on the carbs, I'd check the timing. Even check that the right coil is connected to right channel. Are the cams timed correctly, could they be a tooth out?

Andy
 
KERMIT1200 said:
If timing is not correct, the mixture screws will not any or no effect. Considering the amount of work carried out on the carbs, I'd check the timing. Even check that the right coil is connected to right channel. Are the cams timed correctly, could they be a tooth out?

Andy
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I have encountered SF with the timing a tooth out, running poorly and really lean at low revs and getting better at higher revs. An easy check is to see if you get vacuum after tdc compression, you can cover the plug hole with a finger and rotate the engine forward past tdc and you should feel it sucking your finger in, can pop it off and you hear it.
 
I don't suppose the carbs have those removable screws into which balancing spurs can be screwed, and one of the screws is missing? The issue just reeks of air getting in at high vacuum (= low revs and low slide position).
 
I once had one of the balance bolts fall out heading into Tamworth, the other 2 were loose. It suddenly ran on 2, or that's what it felt like, really obvious, a lack of power. I had the bike serviced by the NSW Distributor, and they balanced the carbs but didn't tighten the bolts afterwards. No damage thankfully and it ran great with a new bolt. They never worked on it again after that fuck up,
 
Air leak via the carb vacuum pipes? (the pipes that connect all three carbs via the brass spigots) - I had a popping and banging issue at low revs with my 1200 and found that these pipes were loose on the spigots, so drawing in air.
Replacement pipes and T-piece fitted (thanks DucatiPaddy) and normal service was resumed....
 
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