jetting problems after spending $2000 on mods

the sig mods list this as a 35mm airstryker
personally i'd only run a 35mm on a ported bbk,
others run it, and larger, but seem to be more concerned with all top end "powaa" at the cost of bottom and mids

what needle is in this thing ????
the needles most of the keihins come with are usually way too rich for our bikes

on my 34mm pj, a switch from a "k" sumthin, to a "dgh" needle cured a whole mess of jetting issues for me, others are running the "cel" needle

report back with what needle is in this, and is the float height to spec,
i think that can be found on here......
Keihin ATV Carburetors

write down your findings, a call to /\ carb parts warehouse ended all my jetting woes on my 34mm pj
which by the way is running .............

45 pilot
155 main/162 in colder temps
dgh needle
you shouldnt be much, if any, richer jetting than mine,
as your choice of an FMF pipe is holding you back, versus my left bend F7

i'm gonna guess your too rich on the pilot and needle, and those are also effecting the main

assuming the float height is correct.......
what airscrew setting gives you the highest idle ????
under 1/2 turn out = smaller pilot
over 2 turns out = larger pilot

it must be certified leakproof,
the float height, pilot and the correct needle, before trying to jet the main, then plug chops to confirm what each jet is telling you "rich or lean", not just blindly jump up and down
 
Last edited:
turbowrenchhead said:
This is my first 2 cycle build. I bought the machine last year and it had a lean burndown last year summer when my 300 pd friend rode it hard and through many puddles. So I found this board and I took everyone's advice on what combination to build.
I took it up north in October in 50 degree weather. I had a 55 pilot and a 160 main. It made great power from zero to 1/3 throttle. After 1/3 throttle it doesn't keep pulling, it leveled off. When I got to the railroad tracks I got it up into 6th and tried to get some top speed. It seized up. I let it sit a minute and it fired right back up. It did that three times that weekend. I tore it down and it had a multipoint siezer. So the engine builder was kind enough to warranty the work. He brought the cylinder to piston clearance from .002 to .004. I got it back all together a few months ago and I took it out on the ice in 18 degree weather after being properly broke in. I started running it a little hard and it seized once again with the bigger clearance. I talked with my local machinist and he was thinking that I was running way to lean on the main jet. So I got sizes 180,190,200 and 205. I took it out yesterday in 35 degree weather on the frozen lake. I tried the biggest jet first. It fell on its face after half throttle and bogged. I worked my way down to 180 with the same results, the bog just got a little lighter. So I put my 160 back in. It didn't bog after half throttle but it just doesn't pull at all. It levels off after 1/4 throttle. The thing pulls real hard up to 1/4 throttle and thats it. I had my gps and all I could get is 56 mph at the most and this was at 1/4 throttle. After changing jets a few times I notice after a few hard runs that I had crankcase oil coming out of the vent tube. Perhaps I have bad crank seals. I did a leak down test after the first rebuild but I have not since then.
I think I'm still to rich on the main and I'm getting a lean condition at half throttle from leaking seals. They are new seals, but I've seen new parts fail in the past.
I'm getting very frustrated at this machine. I've spent so much time and $ on it to have it not much faster then stock. My neighbor a few blocks away has a big bore blaster and he can do 91 mph with 14/38 sprockets WTF!
Click to expand...

Never any mention of WOT, the needle controls throttle openings up to 3/4 throttle when the main joins in.

Have you tried messing with the needle some.
 
With all the seizes I'm lost at if something was done after the last, what break-in procedure you're using, and if you are letting it warm up correctly and if you have been rejetting for the different wether conditions you have listed. Did you EVER do a leak test??
 
My 35mm stryker is at 162 and a 48 pilot, cel needle. Do as stated with a leakdown test if that all checks out- check float height-The trick to these PWK carbs I found out is to first start at 1.5 turns out reguardless of what pilot u are using, keep it running by stabbing the throttle if you have to.Then adjust idle to around 1300-1500rpm, I do this by ear, then once it is idling with out using the throttle, and it has been running for at least 5 minutes or so- start on the air screw pilot circut, follow this rule from AWK:

what airscrew setting gives you the highest idle ????
under 1/2 turn out = smaller pilot
over 2 turns out = larger pilot

Once you have that dialed in, it's main plug chop time, I agree that you shouldn't need anything over 160-168! If it were me, I'd put in a 165 and ride it for a good 15 minutes, then put a new plug in, do the plug chop at 5th or 6th WOT, Adjust main as needed.

Then follow this- 1/4 TO 3/4 Throttle

The JET NEEDLE is the most effective component in the range. Changing the STRAIGHT DIAMETER (D) will change the calibration in the transition range from the SLOW circuit to the MAIN circuit (1/8 to 1/4) throttle. A smaller diameter will make this range richer and a larger diameter will lean this range. TAPER (A) changes are only made if there is a problem balancing the calibration between 1/4 and 3/4 throttle. If the mixture is rich at 1/4 throttle and lean at 3/4 throttle, a JET NEEDLE with a larger taper is needed. If mixture is lean at 1/4 throttle and rich at 3/4 throttle, change to smaller taper. If the calibration is lean from 1/4 to 3/4 throttle, raise the JET NEEDLE by lowering clip position, or use JET NEEDLE with shorter length (L1). If the calibration is rich, lower the JET NEEDLE with a longer (L1).


Here is a needle chart for u to compare what u have to what u may need!

7ccf1f75.jpg
 
my advise altho many wont like it. toss that aircrapper carb and reinstall your stock carb and get the damn bike dialed in. ive used larger carbs on these engines and havent had much luck. BUT They do work good as these boys will tell ya but from what i know those stock blaster carbs can still manage 30-40 horse if ur makin more then that with your aircrapper carb then let me know. lol ps your not
 
Triplecrown421 said:
my advise altho many wont like it. toss that aircrapper carb and reinstall your stock carb and get the damn bike dialed in. ive used larger carbs on these engines and havent had much luck. BUT They do work good as these boys will tell ya but from what i know those stock blaster carbs can still manage 30-40 horse if ur makin more then that with your aircrapper carb then let me know. lol ps your not
Click to expand...

I hate to say it, but I agree with a bit of this, I personally wouldn't run a larger carb than a 34 and that would be bbk or heavily ported. With a KOR port job I'm super surprised that you aren't running a TM34 and having him help on the jetting. Regardless, I have had mush luck with the 28mm carbs on a mildly modded motor, and understand the bigger is not always better attitude.

And as far as your issue I'd chime in but AWK and slick got it covered.
 
Triplecrown421 said:
my advise altho many wont like it. toss that aircrapper carb and reinstall your stock carb and get the damn bike dialed in. ive used larger carbs on these engines and havent had much luck. BUT They do work good as these boys will tell ya but from what i know those stock blaster carbs can still manage 30-40 horse if ur makin more then that with your aircrapper carb then let me know. lol ps your not
Click to expand...

do you have proof of your 40hp claim?
 
im with the needle story here. check it and report the code. i had a nightmare with my OKO and the needle. I bet you thats your problem, however, leaking oil etc is a seperate issue and you need to get that engine airtight ASAP.

Wisecos will sieze if they are not properly warmed up..and i mean properly
 
polaristb325 said:
do you have proof of your 40hp claim?
Click to expand...

i shouldent need any its just true its been done before. and as for me i have a built liquid cooled stock bore and stroke blaster thats deep between 30-40hp and at the moment buildin a air cooled stroker with the dt200 motor specs running all this with stock carb size and dont plan to change. theres power to be made everywhere on the engine its just choosing the weakesst links first. and these blaster motor have alot of them.

30hp without any mods pipe anything. stock carb
mugew.jpg
 
I believe It's a cel needle. I will have to check to make sure. I did a leak down test today. Im having problems getting the exhaust sealed. There was bubbles coming out of the gasket a placed in between the engine and flange. It lost about a pound a minute. I siliconed it and I'll let it sit overnight and try tomorrow. I also used ultra grey silicone to mate the cases together when i assembled the engine. That's something I need to fix. I also found the plug cap was out of spec by 300 ohms to high. I was wrong on the pilot size. There is a 48 pilot in it. That's the smallest one I have. I also have a couple of dents in my fmf pipe. Ken said that it can certainly effect performance. I talked to ken today and he gave me some good advice on what to do next. I have to say ken has been very helpful and easy to talk too. I should of had him assemble the motor, but I'm a cheap ass and like doing what I can myself. I wish the was a blaster guru in my area that I could bring it too, but no such luck. Hopefully with the help of this board and ken I will figure it out. Thanks in advance!
 
Last edited:
Ultra grey silicone is ok. That's the same as yamabond 4 or threebond 1194.

A few dents in the pipe will not make the engine just stop running all together at a certain point, it just may not put out quite as much power as it COULD if the pipe was straight.

The spark plug cap being too high in ohms could have something to do with it, that would make it much harder for the spark to travel down through the spark plug. Might be part of your problem....
 
IMAG0151.jpg

IMAG0150.jpg

The plug wasn't changed during the jet swaps

I have seen gas eat away ultra grey silicone. So I would think it will eventually eat the silicone out of the case halfs around the crank.
 
Last edited:
And oddly, yamaha recommends that in the book, crazy huh? What keeps that silicone safe is the limited surface area that the case mating surface offers. That's a tiny little thin layer turned sideways.

Gasoline hardly ever collects in the bottom end either without being diluted by left over oil either...
 
Blaaster said:
Never any mention of WOT, the needle controls throttle openings up to 3/4 throttle when the main joins in.

Have you tried messing with the needle some.
Click to expand...

I couldn't even get to WOT with the 180 and bigger jets. With the 160 in it WOT was the same as 1/2 throttle.
I have not tried moving the needle. I've always read that you should start with it in its middle position.
 
You must log in or register to reply here.

Similar threads

Saimon69
MY YZ250 SWAP BLASTER BANSHEE INSPIRED
Replies
0
Views
150
Engine Mods and Swaps
Saimon69
Saimon69
Y
Help jetting for a big bore bore
Replies
6
Views
142
Carburetor
KKane
K
B
Blaster with a full Vito’s kit worth keeping
Replies
1
Views
145
General Support
RIDE-RED350r
RIDE-RED350r
J
Power?
Replies
3
Views
516
General Support
Lindso
Lindso
T
Piston Skirt Explosion
Replies
1
Views
304
Engine
RIDE-RED350r
RIDE-RED350r
Top Bottom
Back