Piston/carb ?s when oversize

[bountyhunter]

Ok I just brought a new to me blaster 2002 model the guy that had it before me just rebuilt it
he put a .020 over Namura piston kit in it.
My ?? is will these pistons hold up as good as a stock Yamaha piston or Wiseco Piston
I know from rebuilding snowmobiles that some aftermarket stuff will not hold up that well
now for my second ? he eliminated the oil injection system!
what should I mix fuel ratio to properly lube engine
and also maybe it just that its cool(20-30 degrees) up here right now but it seems way on the lean side,
should I increase the main jet size/raise needle up some for the overbore and oil going thrue the Carb
Thanks

 

[Blaaster]

32:1 is the usual, with an oil designed for air cooled motorcycles.

I prefer 25:1 as I am old school and want the ultimate protection for my motor.

Namura piston will serve you well, but increase the size of the main jet by one size to compensate for the oil taking place of gas in the mix.

Plug chop to confirm.

 

[Awk08]

/\ that

and yes, raise main jet size to compensate for the colder temps, it's a common mistake to not rejet, and fry pistons.
colder air is denser and effects the air/fuel ratio.

i jump 2 main jet sizes larger for temps in the 50's down into the 30's, and do not ride under freezing or i'd prolly go another 1 or 2 bigger.
fouled plugs are much cheaper to replace than pistons.

 

[gb blaster]

sorry to thread Jack but I e was wondering is 260 to small to ride in snow with stock blaster no air box lid an maybe a DG pipe could be stock? I p're mix also.

 

[Blaaster]

sorry to thread Jack but I e was wondering is 260 to small to ride in snow with stock blaster no air box lid an maybe a DG pipe could be stock? I p're mix also.

#280, #290, plug chop to confirm.

 

[Awk08]

sorry to thread Jack but I e was wondering is 260 to small to ride in snow with stock blaster no air box lid an maybe a DG pipe could be stock? I p're mix also.

plug chop to confirm any main jet changes, it's the only sure way to tell for your exact temps and elevation.
guessing = $$$

 

[gb blaster]

Yeah true that I'll chop before I ride go big tO start

 

[bountyhunter]

ok thanks
another ? if I may I here that guys or taking the airbox cover off what other engine mods (cheap) LOL can I do to increase Performance! its has stock pipe and silencer/carb air box and filter
also when i purchased this mine my son and I picked up an 96 for him,with FMF Fattie Pipe and differant carb. (IE Lever type Choke/enrichment) with K&N Filter that clamps onto Carb
what everyone else using with bigger carbs and how do you keep water from messing it up?

 

[Awk08]

jet up about 2 main jet sizes for removing the airbox lid, plug chop to confirm, adjust airscrew for highest idle.

a properly, well oiled filter will repel any incidental water.
"Outerwears" brand covers are available for even more water protection

 

[Blaaster]

Placing an air filter directly on the carb throat will need 1 or 2 sizes larger main jet to handle the increased air flow.

If you put a filter directly on the throat if must not be a paper one otherwise gas blow back will destroy it.

 

[joeak47]

Placing a filter directly on the throat of the carb makes a carb harder too tune. Thats why the stock air box (like most) have a bit of a run (venturi) to help straiten out and speed up air flow.

 

[Blaaster]

Gordon Jennings teaches that for maxium flow, which produces maxium power the filter should be directly at the carby throat, but you need to jet for it and a stock 26mm is very easy to jet.

 

[bountyhunter]

Not sure if it,s a stock 26 mm carb or not did the 96,s have lever type choke or did all the years use same stock carb
when warms up againg will do plug check to make sure it,s jetted right

 

[Larry's Shee]

Blasters never had a lever type choke. Look to see if it has a name on it or maybe post a pic

 

[Awk08]

Placing a carb directly on the throat of the carb makes a carb harder too tune. Thats why the stock air box (like most) have a bit of a run (venturi) to help straiten out and speed up air flow.

it has been the experience of many on here, when switching to a pod filter, a 4-6" velocity tube eliminates
the jetting havoc a direct to carb filter causes,
no matter what GJ says in a book.

 

[bountyhunter]

will post pic of carb if I can LOL

 

[best]

it has been the experience of many on here, when switching to a pod filter, a 4-6" velocity tube eliminates
the jetting havoc a direct to carb filter causes,
no matter what GJ says in a book.

I totally agree with this Awk.
Gordon Jennings is wise in pretty much all things and has stood the test of time, but I disagree with him here.
Filters directly on the carb have always been hard for me to tune, 2 strokes and 4 strokes.

Moreover, it is impossible to keep pod filters dry in that low location if you are going through any water at all.
I do like an airbox that draws its air in high and forward.

Steve

 

[bountyhunter]

IMG_20121229_141133.jpg photo by lahfsh | Photobucket

 

[bountyhunter]

heres a the pic on first post sorry not good with pics lol

 

[best]

heres a the pic on first post sorry not good with pics lol

My Blaster came with that setup, Triplecrown tried to run it. We found poor results.
I put pods on my KZ1000. Spent over $100 in jets trying to get the jetting right.
Found that at highway speeds I put my hand down by the carbs and vary the power of the engine (mixture).

Even on automobile engines I found better results with a filter housing on than off, even with no filter in it.

Steve