Well.
Everything is back together.
Compression on no 2 cylinder is 70-100, not great, but better than 0. All I did was remove the exhaust valve, and lightly brush down both edges with
wire wool. I retested with Fuel in the port and it seems to have cured the leak. I replaced the Valve Stem seals on this and no.1 exhaust valve.
Balanced the carbs on the bench using 2 3mm drill bits, they were all out by a fair bit.
It definitely idles a lot smoother now, but still cuts out at low RPM. It was running for so long that I thought it had been fixed but no.
when it does idle I'm now getting more pops and farts than before.
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posted on 29/9/13 at 01:12 AM
Number 1 still 50? I thought as a rough guide compression should be above 100 think you should have lapped in all the valves while you had the
chance, also confirmed that the chamber held paraffin /fuel with the valves shut.
quote:Originally posted by RichardK
Number 1 still 50? I thought as a rough guide compression should be above 100 think you should have lapped in all the valves while you had the
chance, also confirmed that the chamber held paraffin /fuel with the valves shut.
I don't have a lapping tool for that.
I tested 1 and 2 with Fuel in the port after the clean up and they both held up OK. I did the same thing before the clean and it came out everywhere,
so I know that the clean up has done a good a job as I could do in the garage.
I've not rechecked the compression on 1 yet (that I remember!)
I'm slightly sorry that I didn't fit the replacement head instead. It was very dusty and crudded up with drying Oil, so shyed away from a
massive clean-up, but underneath I could see that it was in much better shape that the one I removed and refitted.
What I might do this week is clean it up - jet wash it down and rebuild it up ready to fit, then give that a go - probably not until next weekend
now - will mean a new head gasket and head bolts.
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posted on 29/9/13 at 12:36 PM
Bolts are ok to re use 2 or 3 times in my view but as you don't know the history you're probably wise to replace.
As we're both unsure what is the correct float height, I wonder if some kind sole wold stick a clear tube on the bottom of there overflow and
let you know the reading?
Sure there are plenty of R1 carb setup out there, mine are honda hornets so can't help.
I noticed that the fuel pump was clicking intermittently, even though the engine wasn't running, this was after I lowered the floats
yesterday.
So I fitted a fuel regulator just before the carbs. It's a cheap dial type
(like
this), so wasn't really convinced it would make much difference.
It seemed to work then cut out again after about 2 minutes of just on idle.
I tried again and just let it run, it started to faulter again so I blipped the throttle and then it just ran and ran. I don't know what RPM
it was running, but seemed a lot lower than 2k. I didn't have the laptop fitted as I was just closing everything up for the night
The proof of the pudding will be trying to start it up again tomorrow, and it continuing to run.
I probably now need to sync the carbs properly, before starting to fine tune the jets.
Incidentally compression on no 1 is now 80PSI - still not great I know. I've another better head being rebuilt, for next weekend
Thanks all for your help. Will let you know if I get any further problems with it over the next couple of days.
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posted on 30/9/13 at 09:19 AM
Mmm I had one of those and it reduces flow as well as pressure, what bike pump are you using, you're not using the mechanical pinto pump are
you?
Off to look through previous posts...
Glad you're getting there
Ok bit of a recap needed, what is your float height at now, below the joint?
Main jet size?
Idle screw set back to standard?
Don't forget to dump the oil if you think it could be thinned with petrol.
My instinct is saying the floats are now closing off the fuel in the carbs hence the occasional blip of the fuel pump which mine does from time to
time but more likely is that you're very close and needs tiny bit more of adjustment. Just to ensure they all shut at the correct level, it
could of course mean a float stuck just for a moment and has now cleared which would be nice.
Ok bit of a recap needed, what is your float height at now, below the joint?
Main jet size?
Idle screw set back to standard?
[Edited on 30/9/13 by RichardK]
Hi Rich,
I think you are right. I'm still convinced my problem isn't solved. It comes down to too rich a mixture, or flooding causing the engine to
stall. I tried taking a Utube vid but obviously it went on forever and didn't fail like before, even though it did 10 mins earlier.
I've uploaded it just to give an all round picture of what's going on. - YouTube Link
Removing the choke also causes a stall even though the engine is hot and the fan has kicked in.
Fuel level still running 9mm above the float bowl\carb join, even though I have adjusted the float tab.
Mains = 175
idle screw about 2 3/4 turns out
On the last run the exhaust gases banged when I cut the ignition - too rich still, I could smell it.
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posted on 1/10/13 at 11:52 AM
Hi Rob
In the picture the tps sensor on the end of the carbs is disconnected so I'll make the assumption your running map but didn't see any
method of taking the vacuum collectively off all 4 intake runners? I used tps and 2d map and worked great with the megajolt.
You are showing the float level on cyl 4 which looks high to me but we could do with some kind soul test there working carbs, I did notice that in the
video carb 1 was spitting and popping fuel which usually means float height is to high so is this carb got a different height to the other 3?
Spitting can also be caused by bad valve timing, have you got an adjustable vernier cam fitted, I don't profess to know how this is done as I
have a good mate in Mookaloid who helped me do mine but did involve a lot of precise adjustment and a dial gauge down a plug hole! I remember it took
a while but it idled sweet after that.
I am using tps, just disconencted in the picture as I had just taken them off and put them back again. It looks like it was disconnected in the vid
too.
All the carbs are the same level as shown.
The spitting stops once the engine has warmed up.
Vernier fitted - but not touched this - just set to TDC markings on teh head and block.
[Edited on 1/10/13 by RobBrown]
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posted on 1/10/13 at 12:20 PM
Spitting at any temp isn't right, but does give us the clue of incorrect float height or valve timing.
Maybe stick a another post on here specifically asking for a float height check using the tube method or asking if there is anybody close that you
could go with your bit of tube and check
TI'm finding this thread very informative. It's also completely persauded me not to spend money on bike carbs and a manifold, setup etc
and to stick with my 38/38 dgav downdraught which starts first time.
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posted on 1/10/13 at 01:47 PM
If your dgav or degas is working for you then fine, I changed from my dgas as I wanted better performance and better mpg which my bike carbs gave over
the dgas and also their is a bit of bling factor
I personally think Rob's been sold some carbs that have been messed about with previously and he's suffering as a result, if you can get
some carbs off a running bike and the fuel pump, chuck in jets to suit your motor and in my experience that will be good enough to get you to a
rolling road.
I wouldn't let this put me off, I haven't regretted my change one bit.
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posted on 1/10/13 at 02:28 PM
quote:Originally posted by RobBrown
Vernier fitted - but not touched this - just set to TDC markings on teh head and block.
so its not set to not the actual TDC then
here's the 'how to' from vulcan - note they don't trust the TDC marks on the block or the head !
but best to follow you cam manufactures advice for the initial setting, then maybe try a few degrees each side of that to see if it improves
quote:Originally posted by Not Anumber
It's also completely persauded me not to spend money on bike carbs and a manifold, setup etc and to stick with my 38/38 dgav downdraught which
starts first time.
like richard says this is probably just a dud set of carbs
but if you really don't want these hassles you can always pay someone to sort it for you (bogg bros etc...)
btw Rob, where did you get these carb's ?
you seem to have had a lot more than your fair share of issues with them
quote:Originally posted by RichardK
Spitting at any temp isn't right, but does give us the clue of incorrect float height or valve timing.
Maybe stick a another post on here specifically asking for a float height check using the tube method or asking if there is anybody close that you
could go with your bit of tube and check
quote:Originally posted by mcerd1
can you get your hands on a dial gauge or two to check the timing properly ?
(I'd lend you one if you were a wee bit closer )
you'd be amazed how far out they can be on the timing marks, so its worth checking before you blame the carb's again...
No-one I know does anything close to this.
How far out is it likely to be. Could mean having to adjust the trigger wheel if the Crank is out by a lot.
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posted on 1/10/13 at 09:37 PM
^^but adjusting the trigger wheel will not sort the timing of the cam to the pistons - its the whole point of the adjustable cam pulley
if your using the stock cam its not tuned enough to matter within the specified tolerances (i.e. the lowest common denominator approach to engine
tuning)
if your using a performance cam changing the timing by as much as 2° could make a big difference to the way it runs as the margin for error is much
smaller
you can get a decent enough gauge fairly cheap - you'll only need one and one of those big protractors you get with the cams or the adjustable
pulleys.
machine mart have ones for about £15 + £10 for the magnetic stand - but google for 'dial test indicator' and you'll get lots of
choices (the plunger type ones the best all rounder)
burton power have a guide on page 6 of the catalogue: linky
or I can send you some more detailed stuff for the pinto if you send me a u2u with your e-mail address
and as a bonus it'll also let you check your real TDC position against the trigger wheel (not that it matters much if its out a little, you can
just adjust the software to compensate)
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posted on 2/10/13 at 07:59 AM
^^ you'll need to make something to stick down the spark plug hole, i've seen a few versions that used a hollowed out old spark plug a a
slide (if it slides well its less likely to jam)
but you don't actually need a dial gauge to find TDC (it's needed more for the valves than anything else)
you can make up a solid bar that screws into the spark plug hole and sticks out just enough to stop the piston before TDC (often just an old spark
plug with a bolt welded on the end)
you then fit your protractor to the crank and a pointer
turn the engine forwards slowly till it just touches the stop - take a note of this angle
then turn the engine backwards slowly till it touches the stop from the other side - take a note of the angle
true TDC is the the middle of these two angles
so you can remover the stop, turn the engine to the calculated TDC position and then zero the protractor (without moving the crank)
if you think that sounds complex its no worse than you need to do with the dial gauge - as the piston actually 'floats' for a few degrees
you need to do a similar procedure to find the true TDC
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posted on 3/10/13 at 08:51 AM
Just tape a wooden skewer or similar to the end of the dial gauge and stick down the hole and then set it up on the stand and zero it out at the
highest point of the piston stroke, takes a bit of fiddling but defo worth the time to get it spot on.
Carbs now sync'd up using a combination of devices
TDC on crank (using a tool rather than sight) shown to be exactly on the pulley mark - surprisingly!
With the megajolt disconnect and the choke on it idles sweetly. With the afr connected it appears that when the choke is off the
mixture is way too lean (up at around 20). I've refitted the filter just to bring the air flow back down a little
Main jet is drilled out to 2mm as recommended by BaileyPerformance earlier in this thread. Initial needle position at the lowest, but slowly moved up
to try and combat the lean issue. Air corrector at about 0.5mm
After everything done - I'm now not getting the stalling issue at idle which is good news. I feel as if I've got this under control
However the MJ is confusing things at the moment because I think the timing is out, so it just accelerates up to about 2500rpm - so may set it to 10
degrees across the RPM range for now, just to eliminate it.
Any recommendations for sorting the lean AFR at idle, with the choke off?
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posted on 5/10/13 at 10:36 PM
Hi rob, can post a screenshot of your mj map and also check that the rev limit isn't set at 2.5 within mj I know it is set low using the default
map to be on the safe side.
What is the plug colour like although wont be truly accurate as its not being run properly for a while just wondering if your afr meter is
accurate?
Glad you're making progress though.
think you should have lapped in all the valves while you had the
chance, also confirmed that the chamber held paraffin /fuel with the valves shut. 
