What would YOU recommend?

[bazwell]

I have an '85 US delivery, and of the top of my head I don't think it's Californian.

The previous owner decided to mod the standard exhaust, but rather than make a long drill and drill a hole like the internet says, he put a long drift down the muffler and knocked the centre bit straight out. The then started it up and revved it until the bits of metal (like core plugs) shot out and flew away.

It sounds great, like a teensy weensy V8 track car. Revs freely, but it's very rich.
It blows black smoke with the vboost open. If I start it cold, I have to ride it to warm it up immediately or it fouls a plug. (Might also be due to the fact that one of the front pipes is squashed.)
Idle is smooth, slightly tending towards stopping, and it's starting to get down to about 85 miles out of a tank. The engine is out at the moment, and the short (2") cast pipes on the back of the engine are very sooty black inside, dark as.

It's standard, apart from the fact that I will put tboost on it as it's goes back together. It's done over 50 000 miles, but I am postponing a proper engine build.

What do you think I should do with the jets?

 

[KJShover]

What do you think I should do with the jets?

Pop in 147.5 mains, and welcome to the collective

 

[PATMAX]

Well you gotta know what jets you are currently run but go with KJ and moving the needles up a clip or ring or whatever they call it sink that needle deeper hence leaner and see what that does is a possibility. There is also shimming the needles which is washer swap fine tuning of the needles. Check out Paul's Shim Kits online or maybe somewhere here hidden in a thread.

 

[PATMAX]

Baz, almost forgot. Please register the last for digits of your bikes' VIN in the thread entitled "oldest surviving Max" on this forum. By the way, you might need an inflatable if your up in the NE territories eh? Stay safe.

 

[Saml01]

85 to a tank is what I get with my Dyno Jet stage 7 kit, mix of spirited and cruise riding.

 

[4gasem]

The front pipes are double tubed, so it'd have to be VERY squashed to have any effect on flow.

If you're running stock jets, I'd look at running the 147.5's. It'll lean you up a bit.

Is your air filter clean? Are you running the correct plugs?

Chris

 

[richwrench]

What about a larger PAJ2 jet ? It's easier to access - it's right under the diaphragm covers on the side. It's an air jet, so you want to go larger to lean out the mixture. Sean has posted that he's had good luck tuning with that jet as it covers a broader spectrum than a main jet does ( off idle, mid-range & top end instead of just top end). I'll be experimenting with it myself here in the near future now that I've established a baseline with the dyno at Capt Kyle's.

 

[maleko89]

I don't see how the PAJ2 affect anything above 5-5500 rpms...just like the pilot screw.

 

[one2dmax]

I think I have the a/f charts somewhere mark. I didn't realize it would either but it did,
Sean

 

[KJShover]

 

[maleko89]

That might be true but I don't want to start changing pilot settings to tune the different ranges. If you are lean or rich on the main jet...change it. Set floats first, then mains, needles, finally pilot...IMO of course.

 

[bazwell]

Thanks guys! I'm thinking I will change the main jets, it's what my guts tell me anyway.

I've never done anything with the carbs, and one of the screws on the diaphram cover looks "tamper proof" so I'm guessing that not much has been done before me.

I'll try and set it up on the bench according to what I can find in this forum, and fit 147.5 mains. Now, where can I get them?

The front pipes is quite squashed. Don't think I'd say very squashed... maybe I'll take a pic and post it.

 

[Rusty McNeil]

I bought mains from the dealer for around $20 for a set of four, they usually have to order them.

If it's an 85 that's new to you, do yourself a favor and pull the carbs off and strip 'em bare, clean them and set the float levels etc,...you may find you don't have any problem with your carbs other than dirt and neglect. Although i too think the 147.5 mains are good too..

Also.... change the plugs AND wires and give it a good going over, igntion problems can really send you on a "carb problem" wild goose chase....sometimes what seems like acarb stumble is just a cylinder not firing until a higher rpm due to shitty plugs or wires..

Also...

Unless the 85's are different than the rest of the years??? then the needles are not adjustable, although they can be shimmed they don't have multiple clip positions..

If you have multiple clip positions pn your needles then someone has installed aftermarket needles and no telling what else in it...

 

[SpecOps13]

That picture is worth a thousand words KJ....

 

[CaptainKyle]

Thanks guys! I'm thinking I will change the main jets, it's what my guts tell me anyway.

I've never done anything with the carbs, and one of the screws on the diaphram cover looks "tamper proof" so I'm guessing that not much has been done before me.

I'll try and set it up on the bench according to what I can find in this forum, and fit 147.5 mains. Now, where can I get them?

The front pipes is quite squashed. Don't think I'd say very squashed... maybe I'll take a pic and post it.

I have Mikuni mains for $ 9 bucks for a 4 pack plus $ 2.50 shipping.