hard to go over 6K RPM, and excessive fuel comsuption

[Znort]

Hello guys
I've got my fantastic 1TX since a couple of months ago. I´ve done some maintenance since I bought it (fork seals, oil change) but not carbs at all. She usually starts fine, unless a couple of times that she was waiting on the street under the rain and it was difficult to start, and when I got it, she started running on three cylinders until she heated. I thought there was some water coming into the carbs, as the bike was standing on the sidestand under the rain for a while, so that question doesn't bore me anymore.
The point is, that the bike runs smoothly and accelerates fast on first gears until I reach the highway and try to go over 6K RPM (well, i not it´s not a completely legal speed, but I'm just trying to see how well is the engine  ). I`ve pushed it one or two times  to 7K but definitively she seemed a bit lazy to get to this speed. Haven't been able to go over this RPM.
Another question is that the fuel comsuption seems excessive to me, about 10 l/100 km (I've read that it should be about 7 l/100 km).
Should I check carburation? valve adjustment? air filter?
Thanks in advance!

[PaulG]

Should I check carburation? valve adjustment? air filter?

Yes

If you've owned it for two months and haven't opened the air filter you could have this inside - check the 2nd pic

http://www.fjowners.com/index.php?topic=16570.0

If not, put a new air filter in anyhow. Are the carbs balanced?  If not, get them balanced and see how it runs.

Before pulling the carbs you could do a valve clearance check. It's simple enough if you have the valve lifter tool which is specific to the FJ http://rpmracingca.com/proddetail.asp?prod=tools%3A90890-04110&cat=39.  "Usually" these things are carb related.

Then pull the carbs - disassemble and clean.  If you feel confident enough to do it check out the Carb Files for cleaning instructions. If not, find someone who is, or take it to an experienced shop and pay the bucks to get it done.  Originally I tried it myself and buggered them up. Took them to a shop who charged me to just fuck them up even more, then I took it to another shop (old timer guys) who fixed them right.  A few yrs later I reattempted it again, then again... then again before I finally got it right.

There are other things like ignition timing, but I would start with the carbs. The air filter and valve clearances can be done while the carb work is being done.

My 2 cents worth.

[FJmonkey]

Many here have sent their carbs to Randy at RPM (see banner add above) and reported excellent results. Your problem description sounds very much like carbs that have been sitting too long. Not sure where you are in the world but the gas here in USA does not store well in the FJ carbs.

[Znort]

Thanx for your help. I live in Spain, so I think it would not be easy and cheap to send the carbs to RPM  I will try to start with the air filter, wich seems easy for my skills, and do the carb sync with a mechanic friend of mine.
thanx again!

[Znort]

And yes, I think the bike has been stored for some 10 years, with very very little use in all these years by his former owner...

[jscgdunn]

Check the files section for carb rebuild info.

[Pat Conlon]

....Another question is that the fuel comsuption seems excessive to me, about 10 l/100 km (I've read that it should be about 7 l/100 km).
Should I check carburation? valve adjustment? air filter?
Thanks in advance!

So (in barbaric terms) you are getting about 23.5 mpg (10 L in 100km) and you think you should be getting 33.5 mpg (7 L in 100km)

You should get better than 33.5 mpg. I have a 1380cc FJ engine with 42.5 pilots, needle fully raised and fat 130 mains and I get 33.5 mpg.

A standard FJ engine (in tune) should get an easy 38-45 mpg.

I agree with Paul. If the bike starts and runs well....before you pull the carbs off for cleaning, try synchronizing them first. Look and see if any are far out of balance.

Paul also brings up a good point on the valve clearances, check those asap. You might have a couple that are tight, and all your fuel and compression ends up going out the exhaust valve(s)

Cheers   Pat

[balky1]

....Another question is that the fuel comsuption seems excessive to me, about 10 l/100 km (I've read that it should be about 7 l/100 km).
Should I check carburation? valve adjustment? air filter?
Thanks in advance!

So (in barbaric terms) you are getting about 23.5 mpg (10 L in 100km) and you think you should be getting 33.5 mpg (7 L in 100km)

You should get better than 33.5 mpg. I have a 1380cc FJ engine with 42.5 pilots, needle fully raised and fat 130 mains and I get 33.5 mpg.

A standard FJ engine (in tune) should get an easy 38-45 mpg.

I agree with Paul. If the bike starts and runs well....before you pull the carbs off for cleaning, try synchronizing them first. Look and see if any are far out of balance.

Paul also brings up a good point on the valve clearances, check those asap. You might have a couple that are tight, and all your fuel and compression ends up going out the exhaust valve(s)

Cheers   Pat

I don't know if the European bikes were somewhat different, but 6.5-7.5 L/100 kilometers is a normal consumption for FJ here. My does a bit under 6.5 with speeds up to 150 kph. On 170 kph and above gets easily to 7.5, especially with head wind.

[Znort]

thanks!
I'll try to do my carbs sync ASAP, and tell you how it works...
Cheers

[Ericcurreri]

I had same problem with my 85 fj1100 changed my plug wires and caps and adjusted my carb floats. Solved my issues

[Znort]

Hello guys!
I couldn't try to solve the problem until last week. Looked valve clearance, they were all OK. The carb diaphragms are not so bad, the sparks are nice. But the air filter...  Seemed like been there catching dust since 1987... So I changed the filter, and... voila! Wonderful acceleration and top speed.
I`ve been riding yesterday at Jarama circuit, next to Madrid (World Championship took place here until the early 90's), and it was an absolute pleasure. Got more than 200 km/h in the fastest lane...
thank you all!

[fj1289]

Do you have any more pics of the bike?  Especially the larger solo tail section?

Thanks!

[Mike 86 in San Dimas]

On the difficult to start after rain (does not rain much here, but would happen after I washed it). Never happen when it was young, started during mid life. . I replaced the coils this year and silicone greased all the electrical connections. That problem went a way. I tend to think it was the silicone grease. The coils "looked" OK.

[Znort]

Do you have any more pics of the bike?  Especially the larger solo tail section?

Thanks!

[fjbiker84]

You may want to try some strong carburetor cleaner treatment in your gas and see how that work.  When I first got my FJ it had sat for 7 years and not properly cleared of gas from the tank and carbs prior to being put in storage.  It had real problems accelerating after getting it running.  I put a good amount of Marine Foam in the tank and ran that for a while.  Since it was close to winter setting on I put the bike up for a couple of months.  When I came back to it the next spring the bike ran like a champ.