Ok guys need your expertise
Just fitted twin 1 1/4 to a 1275 A plus.
First it wouldn't fire up, found the inlet manifold was too high allowing air in so refitted it lower.(it has a big bore inlet head but had a 1 1/4 inlet with hif 44 and ran great)
Engine fired up but won't run properly.
It revs itself really high then drops and revs again
What have we done wrong?
Any suggestions how to fix welcomed
Steve
I think the exhaust manifold could well be stopping the manifold seating correctly.
I think the weld is a tad too high on the manifold and I will have to grind it a little.
Sounds lean.....I used to have to braze half flat washers to the thick flange washers accomodate and to clamp the factory manifolds with aftermarket headers for the suggested problem you might have...
"You must learn, Keats, there are more things to life than breaking and entering."
Going the hs2 twin route on a 1275 with A big bore head cause it won't flow enough to use what spec you've got better off with a hif44 or twin hs4 or twin h4 carbs
Chalkie wrote:Going the hs2 twin route on a 1275 with A big bore head cause it won't flow enough to use what spec you've got better off with a hif44 or twin hs4 or twin h4 carbs
Maybe a period mark could be useful in that sentance?
Capital letters are indeed a good invention as well
Found the problem, took the inlet manifold off and can see where it is hitting the exhaust manifold, also the flanges on the exhaust are thicker than the inlet.
The inlet flanges are worn down from years of tightening up the manifold.
Going to get a Maniflow inlet which should cure the problem.
Anyone used a Maniflow 1.25 steel inlet.
Steve
