Right Cylinder Running Hot? + Backfire

[Namastebuzz]

1998 R1100GS

Right cylinder seems to be running hotter than left. I've noticed this when riding in sandals (Yes - I know!). My right foot gets REALLY hot. Seems to be a bit more heat discolouration around the RH intake too. Riding in boots I don't notice.

Also, the engine is backfiring a bit on the overrun. It may be the crappy Nepali/Indian petrol I'm using. I'm presently up into the Himalayan foot-hills too.

Otherwise - it's running well. Did valve clearances and synchro'ed TBs (thanks Roddy) so it goes very well. Plugs are in good nick and the right colour. Oil is fine and running at normal temp on the gauge. Throttle cables properly seated.

Is this heat problem normal? Is it related to the backfiring? Is there nothing to worry about?

 

[Blackal]

1998 R1100GS

Right cylinder seems to be running hotter than left. I've noticed this when riding in sandals (Yes - I know!). My right foot gets REALLY hot. Seems to be a bit more heat discolouration around the RH intake too. Riding in boots I don't notice.

Also, the engine is backfiring a bit on the overrun. It may be the crappy Nepali/Indian petrol I'm using. I'm presently up into the Himalayan foot-hills too.

Otherwise - it's running well. Did valve clearances and synchro'ed TBs (thanks Roddy) so it goes very well. Plugs are in good nick and the right colour. Oil is fine and running at normal temp on the gauge. Throttle cables properly seated.

Is this heat problem normal? Is it related to the backfiring? Is there nothing to worry about?

Call me stupid, but could it be that the RH cylinder is further back than the LH one and it is just the closer proximity of your foot to the unit?

Al

 

[Namastebuzz]

Call me stupid, but could it be that the RH cylinder is further back than the LH one and it is just the closer proximity of your foot to the unit?

Al

That's entirely possible. It is nearer the foot than on the LH side and my right foot is generally further forward on the peg to use the back brake too.

 

[Timolgra]

Of course it could be that the left hand cylinder is running cold

 

[snoopy]

Spot the optimist!

 

[boarder]

Spot the optimist!

No that can't be right, he'd say "the cylinder was half full" if he was an optometrist.

 

[Namastebuzz]

Another point - took off fuel tank as well whilst servicing (getting it refinished). It's possible I re-connected the fuel lines incorrectly. Would this have any bearing on the matter? Such as incorrect amounts of fuel going to each cylinder.

QAny thoughts?

 

[Vendome 41]

Anything to do with the fact of the exhaust manifold being on the right hand side ........more noticeable when you wear sandals...

 

[Steptoe]

Another point - took off fuel tank as well whilst servicing (getting it refinished). It's possible I re-connected the fuel lines incorrectly. Would this have any bearing on the matter? Such as incorrect amounts of fuel going to each cylinder.

QAny thoughts?

It sound like your throttle cable has become unseated on the R/H side. "They all do that" when you remove the tank -

Should look like this -



But yours could be like this =

 

[ELIMINATOR]

Most commonly posted picture award goes to..........

 

[Namastebuzz]

Thanks Steptoe but 1st thing I checked was throttle cable seating.

Is it possible there's air getting in through the rubber collar between injection pump and cylinder?

 

[Tsiklonaut]

Throttle cables exhausted? I.e. you can get TBs synced on idle and just quickly revving the engine, but on steady throttles old cables go out of balance (they stretch) Any a bit more-than-regular vibrations on various revs you feel through footpegs and handlebars gives you a hint they go out of balance.

BM recommends to replace the throttle cables every 20 000 to 30 000 miles.

Just a theory, don't take it seriously tho.

Margus

 

[Namastebuzz]

Thanks Margus - I guess anything's possible. Though as I said - it's running very well and it balanced nicely at 2000rpm.

Don't want to blindly ignore a serious problem but also don't wanna stop for a minor malfunction.

 

[Namastebuzz]

Well, problem got worse and worse but now it's SORTED.

The rubber collar on RH intake was loose. When I synched the TBs it must have been a bit loose so although got the synching correct - there was too much air coming in on RH side.

When I tightened up the collar - synching was way off again. Borrowed some vacuum gauges and got it spot on now.

No more backfires - runs perfect.

 

[Steptoe]

The rubber collar on RH intake was loose.
.

Part of the service schedule

Plus should always check when balancing T/B's - common sense

 

[Namastebuzz]

Part of the service schedule

Plus should always check when balancing T/B's - common sense

Yep, you're right. Had checked ALL nuts&bolts when I 1st servced bike in Nepal (and tightened many). However, 5 months of riding here with at least 1 mile offroad every day shakes everything loose.

I NOW know to check this.......