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2002 Yamaha F100 questions please

T

tnal

New member
"My local mechanic cleaned out

"My local mechanic cleaned out the carbs and checked the compression of my F100 and found the middle 2 cylinders lower than the 1 and 4 (190 versus 140 for the middle 2). Any chance this is normal or related to the carb- I had ethanol issues I think.

What is compression supposed to be?

He thinks I may need intake/exhaust valve job- any recommendations for Portland, Oregon?

Thanks!"
 
"Okay, let's try this agai

"Okay, let's try this again:

Compression was 156, 115, 140, 190

I was able to run it today and got 6KRPM WOT. Seems to hesitate a littl at 2400 and 3300 RPMs. The idle at 700RPM is rough in gear...

And I am getting more smoke than I remember after running hard."
 
Could be some carbon build-up

Could be some carbon build-up on valves/rings/pistons. Run some strong(1 ounce per gallon) Ringfree through it to remove carbon and it could smooth it out and reduce smoke. Good Luck!
 
"Thanks Robert,

I will give

"Thanks Robert,

I will give it a try. Is Valvetect a good alternative to Ringfree?

Thanks."
 
"Well I ran about 16 gallons o

"Well I ran about 16 gallons of gas with shock qty of Ringfree through it. It actually ran well and I did not feel the hesitation at 2.4K or 3.3K RPMs any more. It's still rough in gear at idle though and there is still some smoke after running hard- the smoke goes away in about a 45secs to a minute.

I will try to run the seafoam or Ringfree additive for now to see if it improves.

J-I-T, I have no idea how to do a leak down test and will check with the mechanic.

What's your opinion on the compression numbers, 156, 115, 140, 190- are these bad and a sign somehting bad is going to happen?"
 
"hell yes

190 in one
and 1

"hell yes

190 in one
and 115 in another is bad

any mechanic that does a compression check on a 4 stroke, is either lazy or they has no clue

2 stroke is for compression
4 stroke is for leakdown test"
 
JIT- Thanks.

Good mechani

JIT- Thanks.

Good mechanics are really hard to find.

I asked because the motor is running really well for the most part and with plenty of power.

I may just opt for a valve job at the end of the season...
 
"ok so 7 years, so around 900

"ok so 7 years, so around 900 hrs?, i think you have maybe 700, more like 435

no mechanics are e-z, technicians are hard!

u own a motorcycle or any atv???"
 
"a compression test is always

"a compression test is always a good indicator of trouble, a leak down test will pin point the problem, read the yta books."
 
"450 hours. No ATV or motorcy

"450 hours. No ATV or motorcycle, why?

I will check out the info on leak down tests, sounds like a good thing to know and will also try to find a tech.

What's a valve job going to cost me?"
 
"I ran the motor yesterday and

"I ran the motor yesterday and had issues with rough idle and it would die if put in gear at idle. It runs fine at higher RPMs. since the carbs were just cleaned out and from reading this board, I think I need the get it synced and linked? I am tired of mechanics and wondering if this is something I could do. I wouldn't mind investing in the equipment.

JIT- would a seloc manual be enough to get this done? What type of equipment?"
 
MAN!!

i'm tired of piss

MAN!!

i'm tired of piss poor mechnics!

over his last month i have fixed 10 boats from shops!!!

yes sync and link

SELCO is garbage

email me for factory
 
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