Upside down inlet rubbers.....

[mr blackstock]

Hello,

So I recently found a wrecked FJ1100 nearby for a few hundred.  I thought "well, you never know, supposedly 100k on the clock, the motor might be worth getting"

So getting it home and closer examination revealed an absolute tosser of a P.O
For starters they made their own 4 into 1 exhaust system that blocked access to the oil drain plug... so who knows how many kms between the last oil change....

The compressions were healthy on three cylinders, bad on one.  Looking over things, everything seemed gunked up with oil.... exhaust ports were oily! SO I'm guessing bad valve seal and being parked on its side stand for years.... the plugs were carboned up, running too rich, and checking the oil it had around a litre too much.

So, I thought I will take my good bank of carbs off my running bike, throw them on, and run the bike, spray in copious amounts of seafoam through the engine and see what happens.

Taking of the seriously messy filthy original bank of carbs, I noticed the carb balancing ports were on the bottom of the rubber inlets.... strange way to put them on.... looking into the inlet ports I discovered the P.O had installed them poorly, all were upside down and sitting askew of the port, effectively 15% of the rubber inlet was blocked.   

Now maybe there was an urban myth years ago suggesting this mod.... perhaps increase the ventury effect to better mix the fuel and air ratio? Or perhaps the P.O was just plain wrong...So wrong... The inner gasket surface of one of the rubbers was seriously messed up with carbon build up... so this bike ran for years like this.... wow.  The 1st pic shows the imprint of where the rubber inlet was sitting, second pic shows the head protruding into the air/fuel intake, 3rd pic gasket surface.

By now I am thinking this motor has got be totally shot.... but as I have gone this far, I may as well see it through and discover how bad an engine can get and still run...

I'll upload a youtube video of the resulting motor torture over the next few days...

[Pat Conlon]

That looks terrible. I have heard that there were "restricted" inlet boots put on the FJ's for the Asian market. I've never seen one, so I wondered if maybe that's what you have...?

 I can't believe someone would install these inlet rubbers like  this....

The horrors of unskilled labor.

[mr blackstock]

I hear what you are saying.  I don't think these are restricter inlets as the carb synch ports were on teh bottom of the carbs and impossible to reach with the carbs installed....

This FJ has been seriously neglected/abused by the P.O

[oldktmdude]

Certainly not the factory restricted inlet rubbers but you would think they were doing a similar job! Some people should not be allowed to go anywhere near a toolbox and some of those same people should not be allowed to own a motorcycle.
It will be interesting to hear about other things that you discover as you get further into the bike.
Regards, Pete.

[RPM - Robert]

AFAIK the difference is in the cylinder head size and the hole being much smaller. I believe they look identical to the US standard inlet rubbers minus the outlet hole side.

[Millietant]

The bike must have ran terribly, performance would have been abysmal for a FJ and I'm guessing the carbs were a mile out of balance st a thought about the oily parts and carbon' up plugs - it's a possibility that the extra oil in the crank cases might have been getting blown into the inlet system by the breather pipe, rather than the bike having faulty valve seals.

It's also possible that valve clearances could be tight,  causing your low compression - if the po was so poor at maintenance, I'd guess the clearances were never checked (or shims replaced) diuring their ownership.

I'd always check the simple/cheap to fix things, before assuming the worst.

If the bike has been standing for a long time, stuck rings could also be a possibility for the compression issue. Have you done the "little oil down the spark plug hole to sit overnight" routine before rechecking?