Triumph T100R Overheating Problems – Any Help Appreciated

[Petergj]

As a quick update, I fitted a new Amal carb from Burlen including 4 Cutaway Slide Hard Anodised, 180 Main Jet, 106 Needle jet and Size 17 Premier Pilot Jet. I ran the bike last week end and the plugs were a very light brown - see pictures. I plan to drop the circlip to richen up the mixture and get a darker plug colour.

The engine still seems to be running hot but I do appreciate other comments which suggest the engine is not running but the right hand pipe of the 2 into 1 is well blue! I did try to measure the head and timing cover temperatures with a touch thermometer but the test was inconclusive - I'll have to invest in the optical device from Maplin as suggested.

Does anyone think the coil could be causing some of the issues? The coil is a single unit with two HT leads made by EMGO. Would it be worthwhile changing the coil for another unit?

Again, any comments appreciated - I am planning to take the bike to France for a rally in two weeks and will cover approximately 100 miles. Time is running out to fix the "overheat" issue if there is really one. I will cover 30-40 gentle miles before going to France.

Thanks for all your comments.

[R]

The engine still seems to be running hot but I do appreciate other comments which suggest the engine is not running but the right hand pipe of the 2 into 1 is well blue!

If one pipe only is turning blue, it suggests your engine is not running equally well on both cylinders.

Put a dab of oil on each pipe up near the exhaust ports, and when you start it from cold, watch which side boils the oil into smoke first.  They should go together. Waving your hand near the pipes can also detect if there is a temp difference between them on startup - but is usually a good recipe for getting burnt fingers. !

If one cylinder is only running poorly, your engine could well be getting too hot as one cylinder labours to do all the work. This really needs to be sorted before heading off anywhere, or to a rally.

Can you switch the coil around, so it fires the cylinders opposite to how it is now ?
If the problem switches sides, you know there is a problem on the electrical side of things.

I missed the start of this, are your point(s) correctly set, and correctly timed.
And the ignition advance side of things correctly advancing and retarding ?

[Petergj]

R, the ignition timing is Pazon and the advance retard works - timing set using a strobe.

I have seen other threads about the exhaust on Triumphs differing in colour - the right hand exhaust pipe getting more blue. I do wonder if the blue is due to the 2 into 1 design and greater flow of hot gases in this area.

I will let you know what happens when the needle is raised and if I can switch the HT leads.

I does not appear that one cylinder is getting hotter than the other - maybe the heat is a consequence of the recent rebore as others have pointed out.

Thanks for your comments.

[Petergj]

Rex, I measured the engine temperatures after a run using a touch digital thermometer and got 55 Deg C on the timing cover at the pressure connection point and 135 Deg C at the third fin from the top on the cylinder head.

I noted the Amal Premier I received from Burlen was fitted with a #4 throttle slide and when running port throttle the plugs are a greyish colour after a plug chop - running lean? Would a move to a #2 or #2.5 throttle slide be too much of a change to richen up the mixture when running at part throttle?

Appreciate any comments.

[iansoady]

Those temperatures sound fine to me.

4 to 2.5 would be too big a jump IMO. Plug chops at part throttle are not very accurate. Unless it's got a flat spot just off tickover I'd leave the slide alone.

TBH I think you're worrying about nothing.

[Rex]

The temps should be comparative as they don't mean much in themselves.
Is the slide not as specified in the manual?
It's a common enough bike and you shouldn't have to do plug chops.
(Incidentally, I don't know if it's correct or not, but some American tuning bloke posted a while back somewhere else that plug chops are only vague at best on ethanol fuel. Can't rely on them anymore it seems}