rough running 1098

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Morrisman58
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rough running 1098

Post by Morrisman58 »

High everyone,
I have just had a new stainless exhaust built and fitted to my minor,i also fitted an lcb manifold which i have taken from my other mog. Of course i had to put an inlet manifold on as well and the inlet was a 4 stud fixing,however the carb is an inch and a half with a two stud fixing! I took out two studs and fixed the carb on with the relevent new gaskets. The inlet had the vacuum plug blanked off as i have no servo. However the car runs uneven now,can anybody tell me why please?? :(

Regards Andy
panky
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Re: rough running 1098

Post by panky »

Hi and welcome along :D
What needle is in the carb, I guess the carb is a HS4.
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bmcecosse
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Re: rough running 1098

Post by bmcecosse »

Make sure there are no air leaks at the carb/manifold junction and at the manifold/head junction. Is the vacuum advance connected to the dizzy ? Is the engine otherwise standard? I would fit an AAU needle..
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Morrisman58
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Re: rough running 1098

Post by Morrisman58 »

Hi,
The engine is fairly standard except for oversized valves and inch and a half carb. On the inlet manifold (water heated) there is a vacuum take off which i have blanked off as the vacuum is taken off the carb. Interesting to note though,the engine was running perfect before fitting lcb and the new larger bore exhaust??
Andy
bmcecosse
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Re: rough running 1098

Post by bmcecosse »

As long as the vacuum is connected - and working at the dizzy? Have you checked? What size valves in the head - indeed -what head? Don't connect the water heating!!! And yes - the LCB is designed for long period cams, and can actually lose power on a 'standard' engine. Still suggest an AAU needle - or perhaps an AAA - although it will burn more fuel.
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Morrisman58
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Re: rough running 1098

Post by Morrisman58 »

Hi,
Sorry for late reply as i work away some weeks!....the head is a standard 1098 with oversize valves(not sure exactly what size) why do you say do not connect water heating? all i have done is fit lcb and inlet and van was runnig fine beforehand.
Thanks
bmcecosse
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Re: rough running 1098

Post by bmcecosse »

Because you want the charge to go in as cold as possible, ' Twin carbs ' don't have a heated manifold (pretty much their only 'advantage')....... so why should the single be heated ?
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Morrisman58
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Re: rough running 1098

Post by Morrisman58 »

Thanks very much for your help,might have to go back to original manifold!
regards Andy
bmcecosse
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Re: rough running 1098

Post by bmcecosse »

As long as it's all airtight - no leaks , it should be good. Double check that in all the fuss - the plug leads haven't been mixed up...... 1342 anticlock round the dizzy cap.
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Morrisman58
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Re: rough running 1098

Post by Morrisman58 »

Thanks again
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