350LC - Better Mid Range Part 2

[muttsnuts]

Thought I'd start a new thread as opposed to making the original one even larger, so this is where I left off in the other thread.

A healthy 47BHP and a very responsive bike with good mid range and pulling from very low down in the rev range.

The spec as it stands is;

1. Standard barrels and head (not tuned or tickled in anyway)
2. 1mm O/S on pistons
3. YPVS Reed block rubbers (not the cages) and YPVS balance pipe
4. Small can allspeeds
5. 230 mains, standard pilots, standard needles
6. standard airbox and filter
7. Standard reed petals
8. Standard 4L0 01 carbs
9. Timing 2mm BTDC
10. Banshee coils fitted

The needles are set on the bottom ring with a further 1mm thick spacer underneath them to raise them even higher.

To completely remove the slight hesitation at 5500rpm then the needle would need to be re-profiled slightly, but I decided that at this point the baseline was good enough.

So to phase 2 - This coming Saturday (30th March)

Test 1 - Fibre Reeds and Modded cages
1. Change to fibre reeds
2. Modify the standard LC cages slightly for better air flow (see below)
3. Check, configure and test on the dyno

Test 2 - PWK 28 Carbs
4. Fit the PWK28 carbs from the KR1S
5. Check, configure and test on the dyno

Test 3 (subject to the exhaust fairy turning up)
6. Fit a set of Kenny's pipes
7. Check, configure and test on dyno

Test 4
8. Remove the snorkel from the airbox
9. Check, configure and test on dyno

Compare the results - if I think on I'll get some dyno charts for each test as well

So I am hoping come Saturday I will be able to publish my results of the various tests above.

I have modified the PWK carbs so that they can fitted using the standard LC cable and also keep the autolube system and also keep the standard airbox, I can swap the carbs over in about 15 mins including setting them up now, so I am pleased with the approach plus it means I can easily put the bike back to standard carbs if they prove not to be an improvement.

Anyway, some pics of the mod's I've done to the standard LC reed cages

Before being modded


After being modded




Bike with the PWK carbs fitted




and a quick video of the bike running with the PWK's on, it certainly seems to rev much quicker, but time will tell (ignore the excessive smoke from the exhausts its becuase I was running it on my pre-mix camel tank and had just bleed the autolube system through - so way too much oil in the petrol !!)



roll on Saturday.......

[flames]

this thread is top notch dude.what size spacer have you got between the barrels and your reeds? you say have 230 mains fitted and raised your needles,did you ever try 240 mains? mine ran 220's,but had to upjet to run pre mix for a bit.i didnt have 230's,so had to use 240's but it was too rich,so i dropped the needles one notch.(clip on 2nd notch from top).i know what works on one bike,doesnt always works on others,but on mine,it all but eliminated the bog just before the band.tho i fitted a 6mm reed spacer at same time,so i am unsure whether this was down to one or both changes.
looking forward to the weekend results .

[steve h]

Are the fibre reeds banshee ones mutts? And are you leaving the stops standard? (Not bending them)

[flames]

shouldnt need to bend stops with spacers.i think you bend them because the reeds dont open enough for max flow thro inlets,but spacing the reeds back sorts it.

[muttsnuts]

I am using hytech reeds (I will explain after the test results)

I am using a 10mm spacer, I actually wanted to use a 6mm spacer, but none where to hand, so 10mm it is

Didn't try 240's as basically it was running spot on (AFR) above 6k revs which is when the main is used, below that its the needle and pilot circuits etc

I have set the stops at 10mm, instead of stock 9mm, however, that was a bit of an exercise in itself as when I checked them before hand they where all over the place, all within tolerance (0.4mm of 9mm), but some where at 9mm, some at 9.4mm and some at 8.6mm, so a spread of 0.8mm ! - needless to say, I made a 10mm slip gauge up and set them all to that, so they are nice and equal now !, if I was using steel reed petals then they would go back to 9mm

The proof is in the eating of the pudding, so Saturday will be interesting to say the least

[Deleted]

apparently, the exhaust fairy, is coming to my house on friday morning then i am taking a set of kennys pipes up to muttsnuts and we will see on saturday how they really perform v a set of small can allspeeds

[muttsnuts]

Mar 28, 2013 12:01:46 GMT 1 @micksfocus said:

apparently, the exhaust fairy, is coming to my house on friday morning then i am taking a set of kennys pipes up to muttsnuts and we will see on saturday how they really perform v a set of small can allspeeds

oooo, great I can't wait..... ;D

[Deleted]

This thread is gold... Can't wait to see the results! Good on you for doing it, alot of people will benefit! Cheers.

[Deleted]

just got a text, and the exhaust fairy is heading north, and wants coffee when she gets to my place

[muttsnuts]

ok, so here goes, the long awaited update for you all

I can see you are all chomping at the bit to see what works and what doesn't

First off, I must just say a big thanks to Marsbar for the loan of his TSA pipes, more on that in due course.

I ended up doing more tests than planned, so you need to pay attention now !!

So to test 1 (as above)

Basically made a gain of 0.3bhp mid range and smoothed out some of the hestitation, but made it run richer - odd but true

Test 2 - removed the snorkel from the airbox

Now this was the biggest surprise of the day (give or take), by removing the snorkel (yes that's all we did|), it completely removed the hole at 5k to 5.5k revs and the power curve increased throughout the rev range by some 1hp, with max power going up from 47bhp to 48bhp and with a crisp throttle and no fluffing of any description - so good bit of advice, remove the damn snorkel.

So at the end of this phase, to recap, the bike is as follows;

1. Stock engine (except 1mm O/S)
2. Stock 4L0 01 carbs with 230 mains, standard pliots and needles
3. Standard airbox and foam filter
4. Small can Allspeeds
5. 2mm BTDC timing
6. Banshee coils fitted
7. Snorkel removed from air box
8. Needles on highest setting (richest) plus 1mm spacer underneath them

and now making 48BHP with a very nice power curve with no flat spots, hesitation of anything

Ok, to the PWK carbs, we have an interesting situation now, the bike is running spot on, so these are going to have to deliver something to be worth bothering with

Test 3 - PWK carbs
3.1. First run on 135 mains, basically running way too rich at the top end, so dropped the needles as far as they would go. Still too rich (38BHP at this point and a rough engine)

3.2. Dropped to 125 mains, runs cleaner, making 42bhp, still rich though

3.3. Removed top of airbox (foam filter left in place though), 49.6BHP and running much nicer, now here's the interesting thing, power from way down to near max power is up between 3bhp to 5bhp across the whole rev range

* So - the PWK's DO give much better power delivery from pretty much idle right up to max rev's (max power being virtually the same), however, it get's there much quicker

3.4. Cruise test - holding steady revs. at 4k, 5k, and 6k - e.g the rev's you spend alot of time riding in

There was a slight stuttering between 4k to 6k revs, the bike was running very lean, so upp'd the pilots from 40s to 48's and lifted the needle one notch, the air screws are 1 1/8 turn out.

This cleaned the mid range up and the bike now rev's and accelerates clean from 2k revs right through to 9.5k revs (it will go much higher but that's the limit set on my bike as I don't want to blow it up !)

3.5 The bike is now making some 5bhp more between 4k and 6k revs over and above the stock 4L0 01 carbs so these are a big step improvement in the mid range, top end wise, we lose 0.9 bhp due to the changes above, so now at 48.7bhp

After a little fiddling and tweaking we get the bike back to 49bhp give or take, it is now running very clean and rev's freely and cleanly.

So at this point, the difference to the settings after test 2 are;

1. PWK 28 carbs fitted
2. Mains are 125's
3. Pilots are 48's
4. Top of airbox removed.

Test 4 - TSA Pipes

Ok, the target for the day was to break the 50BHP barrier, we had been knocking on the door of it all day, so big hopes for the pipes

So after fitting the pipes and NOTHING else, we run the bike up

First thing you notice - its fooking loud !! and tick over has dropped off, so they are having an affect

We run them up on the dyno, we do a max power run and ...................................................................................................................

yes, 52bhp straight off, we do a few runs and then do a full rev range power run, so from 2k right up to the redline, there is a gain of between 3bhp to 5bhp across the rev range with a full 3bhp at the top end.

Now at this point we called it a day, but having discussed the pipes we reckon they are good for at least another 2bhp to 3bhp over and above what they are giving right now by jetting and setting the bike to suit them

So, its quite possible that with some fiddling the bike could be making 55bhp and over stock settings, some 5bhp to 10bhp gains over the mid range rev's of 3k to 7k.

So TSA pipes when swapped out will give at least 3bhp and probably 5bhp very easily, with some dyno time, its possible maybe 6bhp to 8bhp could be had, but most importantly mid range is going to be up massively.

The final test is tomorrow if the weather is fine, and that will be a road test, so I will rpeort back after that before I have to give the exhaust fairy their exhausts back.

I'll summarise my findings and thoughts shortly after I've had time to digest it all, plus I'll get some of the dyno graphs up once I've sorted through them

Plenty of food for though there though

PS - Kenny, top pipes mate, well impressed with them, they do what you say, so a big thumbs up to you

[artie]

Fascinating Dave,thanks to you and of course Andy for taking the time to put such a brilliant thread together.

[marsbar350]

cracking write up dave
even i followed it ;D

[Splodge]

The most informative thread I've read for ages I think it has answered a lot of questions which have hung over an LC for many years and you deserve a pat on the back for your efforts

WELL DONE FELLA

[Deleted]

Ooooo my pwk carbs need tweaking and got to get rid of that snorkel

[matt7]

Superb write up Dave, puts the majority of motorcycle journalists to a crying shame.

Top info too

Cheers

Matt

[kpmc]

this will be realy helpfull for all,nice write up ? clear and precise.

[flames]

excellant thread.hopefully it will be made a sticky,coz this will help folks for yrs to come.and help give people an idea of what works and doesnt before they buy things blindly.fantastic.

[muttsnuts]

Thanks guys, its much appreciated, I am already thinking about how to make some more small changes to improve things and I am saving now for a set of Kenny's pipes so that I can explore exactly how much extra can be had from a bog standard engine with just a few tweaks and bolt on parts......there's certainly more to come, although my piggy bank is getting a tad empty now as even I have to pay for the dyno time even if he is a mate, he does have a business to run !! ;D

[steven]

Excellent information, and very interesting reading.
Do you know what the squish band was with those standard barrels?
steven.

[Deleted]

Good work, and very clearly written up. Answers some major questions.

[garyt]

nice read that mutts
a bit more info on reed cage mods
erlenbachracing.net/reedcages%20mods.htm

[muttsnuts]

ok, the acid test - The road test results.............

well, for one, it sure pulls strong and the front end is an interesting animal in the first 2 gears, power wheelies are now the thing, just set off, accelerate and lean forward otherwise the front is up whethewr you want it or not, no blipping of the throttle, no clutch slipping etc, just straight acceleration and its up as you go.

The power comes in strong from around 4k revs and keeps pulling like a train until the redline, 70mph is seen very quickly and you find your short shifting just to stop hitting high speeds very quickly.

Out on the open road, riding is much smoother, low rev's high gear, just wind the throttle back and she starts to pull, you start hitting 5k and it starts to pull really hard.

Drop a gear or two and wind it back and its off like a scalded cat, and the redline comes up very quick, so be ready with the gear change.

Ok, now the down side, the clutch can't take it, I started to notice some slipping at higher revs when the engine was serving up big dollops of power, the clutch was saying, nah bugger off !

So what about that pesky mid range stutter/hesitation, well I don't know what you mean, its all gone, no hiccups, no rough running nothing, just loads of power all over the rev range and a very strong engine.

So what's next, well, I've got to give the TSA'S back, so its on with the Allspeeds and another road test of course.

Then I need to sort out a stronger clutch, so possibly 3 TZ springs, and some new plates just in case I've burnt the ones that are in too much now.

I have my next set of tests lined up so watch this space, target is 60bhp from a stock engine, so just using bolt on parts, is it possible, well I don't know, but its a nice thought - 60BHP from a non modified engine ............maybe............ watch this space.

PS - i'll summarise everything in a new thread, so you can see what configurations work etc, of course, the one thing I can't stress enough is that every engine is different, so having your bike set up correctly on a dyno is money very well spent - at £50 average price, its a small price to pay to know everything is fine and a hell of a lot cheaper than a rebuilt engine or a rebore !

[Deleted]

Dave I put 3 tz springs in the red bike and found the clutch very heavy, in kaf (the yellow bike) I have put 3 yzr500 clutch springs, norbo sells them for £12 for three and I find them a lot better

[foxyjohn]

Your write up is like your user name the muttsnuts thanks for taking the time to share this

[muttsnuts]

hereyago, a short vid of the bike running with TSA pipes, its very loud !!!

s1143.photobucket.com/user/muttsnut5/media/MVI_3118_zpse5965889.mp4.html?sort=3&o=0

[jollyjoiner]

which bit is the snokle ?

[kentracer]

I think he means "duct"
Part 21 on the diagram.



it is, isn't it ?

[jollyjoiner]

Cheers, thats a job to do tomorrow then, see if mine is still there

[Deleted]

think lc petrol tanks up and down the country will be removed to see if they have a snorkel or not ;D
and kentracer yes you are correct

[muttsnuts]

Mar 31, 2013 18:56:01 GMT 1 kentracer said:

I think he means "duct"
Part 21 on the diagram.



it is, isn't it ?

yes you are correct, that's the pesky little bugger !!