RobBrown
|
| posted on 14/9/13 at 07:12 PM |
|
|
R1 Pinto trouble starting
Still trying to tune carbs...
Engine will only start when the idle screw is turned all the way in, but still very lumpy and eventually cuts out. Turning the screw out and it
doesn't start at all.
Does that mean a smaller Pilot Jet? Or something else?
|
|
|
|
|
teegray19
|
| posted on 14/9/13 at 07:19 PM |
|
|
Are you starting with the choke?
|
|
|
RobBrown
|
| posted on 14/9/13 at 07:22 PM |
|
|
choke does make it a little easier, but still requires screw turned in.
|
|
|
teegray19
|
| posted on 14/9/13 at 07:25 PM |
|
|
You'll need the choke for a little while, try idle screws at 1 and 3/4 turns out, are you running dizzy or mega jolt?
I quests if its dizzy you may need some vacuum advance.
|
|
|
snapper
|
| posted on 14/9/13 at 07:28 PM |
|
|
Where is your needle posisions
I found that you can richer up by lifting the needle a bit
Ultimately you will need to rolling road it
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
|
|
|
RobBrown
|
| posted on 14/9/13 at 07:34 PM |
|
|
running megajolt, timing advance at 12
needle in middle, OK for WOT.
Will get it to RR eventually, but would be nice to get it at least starting OK.
|
|
|
jacko
|
| posted on 14/9/13 at 07:41 PM |
|
|
Dose the engine turn over fast enough
What fuel pump are you using bike pump i hope ?
|
|
|
RobBrown
|
| posted on 14/9/13 at 07:46 PM |
|
|
yes, bike pump. battery may be a shy of fully charged after the continued retries, so may be worth waiting until the morning before trying again and
getting the engine up to temp on the choke.
Will try increasing the Throttle position up a little also - currently 3% according to TPS, seeing as seems to run better with a little throttle.
|
|
|
jacko
|
| posted on 14/9/13 at 07:52 PM |
|
|
What size are your main jets my carbs are zx9r's and they have 1.7mm jets with 3/4 turn out on the air screws
Also have you balanced the carbs you will have problems if not
|
|
|
RobBrown
|
| posted on 14/9/13 at 08:00 PM |
|
|
1.7 jets were way too rich, for some reason. Ended up with 120 main jets to satisfy the AFR at WOT.
the fact that the main jet is so much smaller than what I expected it to be makes me think the pilot should be smaller too.
It does seem to still smell rich at idle, however lumpy, especially when I turn the screws out.
Re balancing - I've not separated the carbs so how would I balance then?
|
|
|
jacko
|
| posted on 14/9/13 at 08:10 PM |
|
|
You will need a balance gauge you balance no 1 and 2 carbs then 3 to 4 then 2 to 3
New Motorcycle Carb Carburettor Vacuum Balancer Gauge 2 / 4 Cylinder Gauges Kit
Something like these if you havs balance pipes in your manifold
do a search on here there is lots of info how to make your own
[Edited on 14/9/13 by jacko]
|
|
|
RobBrown
|
| posted on 14/9/13 at 08:23 PM |
|
|
I've already got a carbtune kit.
No pipes on manifold
ordered new vacuum nipples\adaptors from
MorganCarbtune
will see how unbalanced they are when they arrive
[Edited on 14/9/13 by RobBrown]
|
|
|
RichardK
|
| posted on 15/9/13 at 07:44 AM |
|
|
1.2 jet seems incredibly small and potentially running very weak, my pinto ended up at 1.65 jets with the free flowing filters on.
Trouble starting I would be looking at float height as a priority and putting main jets at 1.55 to start with too and as get them synced as soon as
you can get them to run at 3 or 4k
If the carbs are unknown as in cleanliness I would be stripping and cleaning them thoroughly as well and don't be surprised if you have to do
more than once and be meticulous in keeping your work area clean and tidy and do one carb at a time  there are plenty of YouTube videos that show
how this is done too.
I wouldn't even be looking at afr just yet concentrating more on plug colour
Just my 2 pennenth and hope you get sorted soon
If you don't understand how carbs and the different functions different jets do in the rev range, Dan explains it really well
HERE in fact his whole motorcycle course is worth a read for anybody interested in bikes.
Cheers
Rich
[Edited on 15/9/13 by RichardK]
Gallery updated 11/01/2011
|
|
|
RobBrown
|
| posted on 15/9/13 at 02:02 PM |
|
|
Thanks for the advice Rich
I started with bigger jets(1.75), it ran but bogged down under acceleration. Bought AFR meter, and discovered was running too rich at WOT, so have
slowly come down in jet size so that WOT was correct AFR. That's when it stopped starting and idling.
In the midst of all this I've fitted MegaJolt - just because I was convinced timing and Dizzy was causing some of the problems
Can get it to start on the choke, but very lumpy and will eventually stop if not feathered on the throttle enough.
I'm obviously missing a piece of critical info as I too believe 1.2 is too small for a 2.0l pinto, based on the research I've done.
With the bigger jets the plugs were very wet and black.
With the 1.2 jets they are dryer and better. Practically everything is telling me 1.2 is correct even though I'm convinced like you that they
are too small - apart for the starting issue.
Rob
|
|
|
sjmatthews
|
| posted on 15/9/13 at 03:57 PM |
|
|
Something else to consider is the fuel contamination. If its more than 6 months old it could be blocking the idle jets, and they'll need to be
blown through, and the system drained. Make sure the fuel is fresh and you have a filter pre and post pump.
Speaking from my own experience
Good luck
I'll be in the garage dear!
|
|
|
RobBrown
|
| posted on 15/9/13 at 05:45 PM |
|
|
fuel has been in sealed jerry can - does that matter? Will it still be contaminated?
filter pre and post pump
Going to take off and clean carbs through, just to be sure, just so I can be confident of answering these suggestions.
Should be able to check balance as well by next weekend
|
|
|
BaileyPerformance
|
| posted on 15/9/13 at 07:58 PM |
|
|
Have you blocked your air correctors? We have seen this done before, it does increase fuelling even with a small main jet, but makes the fuelling rich
at near full throttle.
If you have blocked them, unblock them and try 1.8mm mains with needles dropped to second from lowest position.
What AFRs are you aiming for at light throttle and full throttle?
[Edited on 15/9/13 by BaileyPerformance]
|
NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
|
RobBrown
|
| posted on 15/9/13 at 09:07 PM |
|
|
yes blocked, they came that way.
Just stripped carb down - 2 of the 4 idle mixture screws rubber O rings split and need replacing
Was trying to keep AFR at around 13, but found most jets caused AFR to drop to 9.
1.2 Jets kept it at around 11.5
Will try unblocking before I put it all back together. Can always block them back up again afterwards.
[Edited on 15/9/13 by RobBrown]
|
|
|
snapper
|
| posted on 15/9/13 at 09:21 PM |
|
|
I have played with Megajolt cranking advance to make engine turnover easier
Check your getting full choke when you pull the cable
Also choke is not effective on bike carbs if you also apply throttle
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
|
|
|
mcerd1
|
| posted on 16/9/13 at 07:29 AM |
|
|
quote:
Originally posted by RobBrown
running megajolt, timing advance at 12
have you checked that it really is giving you 12° ? (i.e. with a timing strobe)
just to eliminate things you could also try running a 2D map (without the TPS) or even unplug MJ and just use the EDIS4 (which should be 10° fixed)
also my carb's came with 1.6mm jets from bogg bros to 'get me on the road' so 1.2mm seems a little small...
[Edited on 16/9/2013 by mcerd1]
-
|
|
|
jacko
|
| posted on 16/9/13 at 06:31 PM |
|
|
Im betting its the air correction holes some carbs like them blocked and some don't
|
|
|
jacko
|
| posted on 16/9/13 at 06:33 PM |
|
|
quote:
Originally posted by jacko
Im betting its the air correction holes some carbs like them blocked and some don't
And the main jets do need to be bigger i would say 1.60 - 1.7 mm
|
|
|
RobBrown
|
| posted on 16/9/13 at 06:59 PM |
|
|
Just drilled them out. they were closed off with solder or aluweld or something, so needed drilling. I was careful as I didn't know how far to
go.
All the brass inserts came out cleanly but the bottoms are all shot. Can I get replacements for these? Or can I run without the insert. I notice that
they are not displayed on the standard Carb schematic and parts list.
I suspect that without the insert there will now be too much air getting in.
I work near a Yamaha dealer, so will pop in there tomorrow to try my luck.
|
|
|
RobBrown
|
| posted on 18/9/13 at 05:25 PM |
|
|
Update...
Fuel drained, old fuel in tintop, new fuel bought
Filters cleaned
Carbs striped down cleaned and put back together carefully
replacement idle screw rubber washers fitted (splits in 2 of the 4)
air correction unblocked
165 main jets fitted
needle clip on middle setting
screws turned out a variety of settings, initially 2, then back to half, then 3 then 4.
but still wouldn't start, even had trouble coaxing it to start on the choke
plugs wet
but... will start with a squirt of carb cleaner down each carb and will then run, but as soon as I try and go back to idle again it dies.
Still convinced that the 165 jets are too big I can smell the fuel coming out of the exhaust, but not had the AFR on it at this stage to check.
So it must still be to do with not getting the idle\pilot circuit mixture right to allow it to start.
Interestingly can't get the carbtune synchroniser to register any readings, from the new adaptors fitted to the manifold (might be a leak in the
tubes, although sucking hard seems to do the trick (Oo-er))
Engine seems to be blowing back through carbs at idle ( I would naturally expect it to be sucking the same as it does at higher RPM)?
I've got bigger pilot jets to fit, which I could try (17.5), but not convinced at this stage that it's going to make any difference
Any suggestions gratefully received at this stage
|
|
|
jacko
|
| posted on 18/9/13 at 05:38 PM |
|
|
My carbs spit back until the engine is hot
I don't need to use the choke to start mine
you could try dropping the main needle to the lowest on the clip
If all this dose not work i would give Bogg Brothers a phone call they are experts on r1 carbs
All this is i can think off
It looks like someone has played with the carbs before you got them if the air holes where already blocked
Jacko
[Edited on 18/9/13 by jacko]
|
|
|
