FJ1200 puzzler

[planedick]

Owner has aftermarket pipes, pretty much straight thru, dynojet kit, original 110 mains replaced with 112 and needle replaced with one with clips for changing height.

First time it was brought to me it was without the original jets or the original springs so I wasn't sure what had been done. I raised the needles and it went from not running at all except with the enrichment circute full on, to running good enough to scare the s**t outa me.

Well, almost a year later and it's back with the same symptons. Won't run at all except with full enrichment. Changed the jets to 114 and test run was good except for above 5000. I guess I will go with the 118 jets in the kit.

The real problem is what is slowly changing. Owner said it was OK at first, but steadly got slower and slower until it wouldn't run at all. I can't think of what would slowly change like that???????

PS I'm told the owner rides like it was a Hardly, low rpm's, puttin' around......

[wa407mpp]

Did he let it set a long time with gas in the carbs?

[planedick]

Riding

He's been riding it regular, besides, I've already had the carbs off and apart for cleaning and rejetting twice so far this time. Something is slowly changing over time and I can't think what it might be. Good compression all across and good spark and the plugs look like the mix has been good. Luckily the bike comes with a service manual and a complete service record.

[LoserShoes]

Sounds like an air leak, maybe the carb holders?

Steve

[FJ111200]

Air filter clogged up?

[planedick]

New filter

Can see right through air filter, no obstruction. Using propane I couldn't see any leaks around the carb holders.

[wa407mpp]

bad gas, maybe water?

[Montreux_Blue]

Clogged fuel cock?

[planedick]

Gas

New gas and it has a fuel pump with new filter and it does pump real good. Don't ask how I know.............

[FJ111200]

Which model is it mate? 1TX, 3CV or 3XW?

Sorry they are the European models. Still, let me know if you can, i'm looking at the manual here with all the model codes.

[madmax-im]

well whats left if it isnt fuel or its delivery?maybe something electrical?

[egsols]

needle replaced with one with clips for changing height.

I raised the needles and it went from not running at all except with the enrichment circute full on, to running good enough to scare the s**t outa me.

If it is slowly getting worse over time, could it be that the needles are wearing? JAT

[FJ111200]

Another one according to the Haynes book of lies is, and don't know how true, and quote,
"Engine oil viscosity too high. Using a heavier oil than the one recommended can damage the oil pump or lubrication system and cause drag on the engine".
Mmmm.

[snowdog51]

fj

perhaps the exhaust is going bad needing more fuel thus larger jets

bill

[planedick]

Can't find a way

How is it possible to hook up the crankcase vent to the airbox after I put it back on? No possible way to access it and can hardly see it even.....