Hooray another jetting thread 04 450

The throttle has no bog now, it's really crisp just seems wrong with the fuel acre bottomed out. I'll take a look at the choke plunger, and post my findings.

I did the oring mod while I had it apart. apparently the previous owner tried his own version of this using basic wire? The stuff used to hold grips on..

Since I won't get a chance to check the choke plunger for a few hours, what are some other things I should look at while I check the choke?

I hear you about throttle response being good ....

 

Screw the O-ring mod on the AP .

 

Order the Merge Racing accelerator pump spring , way more consistant .

Ok. Thanks. Will update what I find. I'm going to assume it's not the needle jet being ovaled out for now as the bike only has 600 miles on it, give or take 50.

I've also never seen a choke that leaks but then again I steer away from jetting stuff usually.

All chokes leak eventually. If you pull them apart, you will see why....

Use Anti-size on the plunger sparingly

While you are there you might as well service the hot start the same way

All chokes leak eventually. If you pull them apart, you will see why....

Use Anti-size on the plunger sparingly

While you are there you might as well service the hot start the same way

I took it off and I'm not seeing why it would leak. Maybe I'm blind. All I can figure is maybe the seal on the end is too old? Here's some pictures ImageUploadedByThumper Talk1423410737.967589.jpg

ImageUploadedByThumper Talk1423410889.000104.jpg

It moves very freely, and holds its place on very well. The hot start was serviced a couple months ago as I had an air leak. Once fixed it solved all mid throttle bog. It has a new oring, plastic nut, and seems to move freely.

Tha'ts the 'old' style plunger. They wear out and leak.

You can grease the plunger to make it seal, but it does not last that long....but that would be a lean issue, not a rich one...

Ok. So I'm thinking I'll order new jets the same size as the current ones as they are correct, in case the previous owner used wire to clean them and it made them bigger. At the same time I will also put a new needle jet. Any other suggestions as to what to check?

You really need to service THE ENTIRE CARB, not just pick and choose what you feel like fixing....

 

http://www.dirtrider.com/features/protips/141_0707_keihin_fcr_carb_rebuild/

 

Rich condtion issue options have already been mentioned more than once

 

- needle jet worn

- air jet clogged

- choke plunger leaking

- acv valve not working properly

- dirty air cleaner

- float too high

I'm trying to find out what the float setting on this thing is. I have 2 of these bikes yet no manual yet.. I keep waiting for one to pop up locally with no luck. I'm sure you know.. Mind sharing?

And yes, every passageway is cleaned out now. Inside the acv, the accel pump, intake bell, all of it. My current float hight is 9mm give or take .3mm

I'm trying to find out what the float setting on this thing is. I have 2 of these bikes yet no manual yet.. I keep waiting for one to pop up locally with no luck. I'm sure you know.. Mind sharing?

You can download Yamaha service manuals from Yamaha's site.

Upon compairing the 45 pilot to a 50 pilot I have sitting around, I can confirm the 45 is way larger than the 50.. Leading me to believe it has been drilled out.

I have taken pictures of the jets, to show what the difference is. Both jets are fully clean as far as I can tell. I checked a 42, and a 50 against my 45. The picture I am showing is the 45 and 50.

This is the 50

ImageUploadedByThumper Talk1423813111.773285.jpg

And this is the 45

ImageUploadedByThumper Talk1423813202.605895.jpg

Both holes are perfectly round. I now believe the 45 was drilled out very large. I believe it would cause the exact issue I am having, but I may be incorrect. I checked the float bowl and set it to the factory 8mm, which actually allows more gas in so it would have been lean with how it was before.

Every passage in the carb is spotless, every gasket fresh. If this does not solve it my last effort would be the needle jet. I will be buying a new one tomorrow when I go to get my replacement jet as I have all sorts of pilots but nothing sized 45.

I uploaded with the best quality thumpertalk would allow. If the quality is not good enough, I can repost somewhere with better quality and link to it.

Keep in mind the 50 picture is slightly more fuzzy than the 45, the 50 hole is perfectly clean, unlike how the picture would make it seem.

Edited by x_JT_x

No one has an opinion on the size of that "45"?

On a side note don't you love thieves who steal your truck blow the motor and leave it? Just makes your day :(

The pics don't matter

Put in a new 45p

 

Was that your truck?

The pics don't matter

Put in a new 45p

Was that your truck?

Yes it was my truck stolen. I've only had it a week and a half. The POS floored it around in first and second, overheated the motor and it now has a massive rod knock and won't shift right. Motor has only been ran about 1 minute since recovery and it's way louder than before.

I now have to pick to spend more than I paid for the truck to repair, or get rid of it which is sad because it's super clean.

This was also my first car. If I catch the POS I will probably break his fingers at the least.

Of the 4 cars he stole last night, all were recovered and only mine had damage. One was spray painted on the tailgate but it came right off.

As soon as I can get to the store to get a new 45, I'll be getting my bike fixed..

Well a bit of good news, the new pilot did the trick. I guess you can't trust previously owned bikes. I can now run the fuel screw at around 3 turns to get good idle. Once I get up to 1500 elevation it should be perfect. Thank you Krannie.

Now on to the bigger project, replacing a car motor.

Move your needle jet to 5 if not 6th position. I'd invest in an adjustable accelerator pump, one that eliminates the leak jet all together. The 04' motor doesn't need a leak jet. I plugged mine with a new Boyesen accelerator pump 3. (Plug comes with kit.) Played with tuning between accelerator pump, fuel screw and have eliminated bog. Main jet I kept stock.

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