Living with a TYGA 300.

First things first, the kits arrived and credit must go to TYGA as everything was perfect.

When fitting the kit I did run into some problems. These were quite easy to fix though. As I was fitting the kit to an MC18, the power valve cables for the top cylinder were a little too long and needed some interesting routing before they cleared everything. I also found that neither plug leads would reach, so new leads had to be made. A new radiator lower mount also had to be made as the stock MC18 one wouldn't fit the 300 barrels. The biggest pain though was fitting the pipes. Quite why I struggled I don't know, but TYGA use angled exhaust stubs which did take quite a bit of time to line up allowing the pipes to slide on and off easily.

Once everything was set up and ready to run, the bike started quite easily and ran well while I was breaking it in. This is when my disaster happened. After a couple of plug chops my power jet blocked and said goodnight to my lower cylinder. I was a little more than annoyed! TYGA sent me a full HRC jet kit, new pistons, and gaskets. In this time I sent the barrel to Langcourt who replated it and got it back to me within a week.

Today I managed to rebuild it and ran it all in. I spent a few hours this afternoon on the dyno and came up with some interesting results.





While it didn't quite make the peak power I was hoping for, it did make over 20% more power around the7,000rpm to 8000rpm range, coming down to a 10% gain above that. It did manage however to make 69bhp on the final run with a little more work still needed. The first run was made with 205 mains which are now 210, using the HRC BB needles. The bike pulls clean right from 3000rpm and makes peak power at around 10750rpm.

The one interesting thing is out of the two engines... I like the 250 better!

do you know if tyga will do a mv18 with the faults mentioned fixed.
Psycho

I wouldnt say there are any faults with it. You just need to jiggle a few things to make a real nice job of it. Having a curved rad like the MC21 would help give alittle more room for the cables but everything will fit if you take your time.
_________________
If I have to take the carbs off once more...

Was it worth the money ? Or just stick with 250cc?
_________________

Stephen,

Unless you have already done it I would check the TPS for correct operation. My MC18 300 with Tyga GP pipes nipped/seized 3 times. I replaced one complete cylinder/piston, tried rejetting and many other things to solve it. Eventually it was traced to the TPS which was working intermittently and advancing the ignition too much as full throttle.
Matt will give you the resisitance to check for 8kOhms or something. If in doubt relpace it!!

Why. Because even though the TPS is part of the "electrical" system it is a "mechanical" part and will wear out.

I'm interested in you preference for the 250 motor.

Mike

I think that for the "normal" rider, the 300 would seem an outstanding improvement. What I mean is that many riders will enjoy the 15-20% improvement in power delivery right up through the mid-range!

If you were to crack the throttle open at 7250rpm on Stephen's bike, then judging by his dyno-graph, you would be getting around 13hp more than a good 250, right where the RC Valves are opening and the power-band begins! It would certainly make the front-end a little lively!

You then get that healthy increase of power right up past 10750rpm, but it peters out rather sharply and doesn't make that much more power than the 250. This means that if you rode it on the ragged edge all the time, very high up in the rev-range, then the difference wouldn't be so noticeable.

I expect the kit has be designed to specifically beef up the mid-range for 2 reasons:

1. For the benefit of the majority of normal road riders

2. In the interests of reliability

I'd imagine we'll soon find out when Matt reads this thread! :D

Just my observations.
_________________
Andy.
NSR-WORLD.COM

Please keep all responses to Forum posts on the Forum so that others may benefit.

Please DO NOT PM me for technical advice. My time is precious, and you will probably receive a faster response on the Forum anyway.

Check us out on Facebook! Please "like" our page!

Stephen,

I now remember that with a faulty TPS the power used to drop off suddenly at about 11,700ish almost to the point of throwing one over the bars!!
Now it revs all the way to the redline

Andy,

Maybe you are right about average riders but maybe that should read "for road use" My bastard child 18 with 21 engine was used as a daily commute until i came ti Indo. Still with the 18 inch rear wheel I dropped the rear sprocket to 40 so was running 15/40. This means it cruises at 140kph at about 8500 if memory serves correctly. I could get my gearing calcs from home if you want.

Of course maybe one has to live in Thailand in Rayong and go to work 20kms each way on a dual-carriage and ride the 60kms each way to Pattaya in the evenings and have either disinterested or non existent police......

Before the faulty TPS was replaced the grunt was much better but that maybe because now the jetting is conservative. Coming out of corner one at Bira and going full chat up the hill into turn two the front used to go "very' light, with a wobble, over the crest to the point where I started looking for a damper. But then it would seize either through Maxima or at the end of the straight ( was that you locked up?) Now it's lost that "crispness but it's eminently reliable. I lost my confidence for a while maybe that's why I went to 15/40? I never used to ride at more that 9000 at partial throttle!

Sorry if this is disjointed but it comes back in bits and bytes as I didn't keep a diary. I remember the siezes by car and location. First two counted as one were on ther same day were on the track, second was "playing" with a 525i coming into Pattaya just past the hwy7/36 junction and the last was "blowing off" a Thai lowrider turbo deisel pickup late at night coming into Rayong after a 220kms round trip from Chantaburi.

That's about all I can think of for now.

mike

Thanks for that mike, I have a few spare carbs so i will try swaping the TPS's over and see if that changes anything.
_________________
If I have to take the carbs off once more...

gotta say the extra midrange really does appeal.
you'll have to let me have a spin mate.

one day, when i've got rid of these damn itchy feet.
_________________
MC21SP - Roth-tax
CBR400 - track
MC21R - sold
MC21SP - sold

StephenRC45 wrote:Living with a TYGA 300.

First things first, the kits arrived and credit must go to TYGA as everything was perfect.

When fitting the kit I did run into some problems. These were quite easy to fix though. As I was fitting the kit to an MC18, the power valve cables for the top cylinder were a little too long and needed some interesting routing before they cleared everything. I also found that neither plug leads would reach, so new leads had to be made. A new radiator lower mount also had to be made as the stock MC18 one wouldn't fit the 300 barrels. The biggest pain though was fitting the pipes. Quite why I struggled I don't know, but TYGA use angled exhaust stubs which did take quite a bit of time to line up allowing the pipes to slide on and off easily.

Today I managed to rebuild it and ran it all in. I spent a few hours this afternoon on the dyno and came up with some interesting results.

The one interesting thing is out of the two engines... I like the 250 better!

Is that what you call perfect? !!!
Its a good job you are a mechanic as some owners would be pulling their hair out with all the problems you have had.

How come you did not fit the HRC jet kit before you ran it though?
How long did you run it on the Dyno for before doing full bore runs?

On the Tyga site it says "This is a SIMPLE bolt on replacement top end kit which radically improves the power characteristics of your NSR250."

Nice graphs in the end though!!

The product was fine. All the little probs just needed some time. Anyone can make a little bracket to hold a rad!

I gave the bike 50 miles before i put it on the dyno and let it have full bore right from the start. The reason i didnt fit a hrc jet kit to start with was because i wanted to work on what i had. Untill the power jet bloked the bike ran very well with stock needles etc.

I think the 300 kit is a huge improvment over the 250 but i like the kick the 250 has more than the grunt the 300 does.. each to there own.
_________________
If I have to take the carbs off once more...

Stephen,

Don't take the carbs off again!!

Find the disconnect/plug on the TPS wiring, get a good multimeter, make a semi permanent connection, if you don't have a friend, sit on the bike and work the throttle while imagining you are going around Donnington Park, Laguna Seca or wherever. No seriously open the throttle in increments. Whilst doing this check that the resistance, I think about 8-9k but you will see, changes smoothly and uniformly. record the readings doing this up and down the range. Slam the throttle open/closed see that there are no jerkingy readings.

Or if you have a timing light check the timing at idle. Mine was advanced rev the bike up see if it changes smoothly.

As you have a spare set of carbs you can check the "spare" off the bike to see what you get before doing the real one.

Mike

IOM,

It is bolt-on. It just is easier on an MC21 which is what was used as the test bed. I beleive mine was the first 18 so now there are 2?

Jetting is very specific to temp, altitude and humidity. As such it is immpossible to test the kit in all permutations.

I was very unlucky that my "donor" bike had a faulty TPS otherwise I probably wouldn't even be writting this.

Stephen you didn't tell anyone that you had to file out the bottom fairing to accomodate the now centrally located plug lead.

As for the power. Remeber the kit may and probably is running standard road port timing etc. I don't know if Tyga has done a "ported" and polished version and even then the pipes play a big role in the eventual power outpput. My bike goes well off the clock flat out. Somewhere near the manufacturers logo!!

Mike

Ok i checked the TPS and all seemed to be working well but i thought ahh heck lets change it away. I swaped it over and spent my lunch time on the dyno again adjusting it untill i got the best power and graph. All seemed to work well. Im now making 71.6bhp so ive cracked the 70 mark, yipee for me!

Yes youre quite right, i also have to take about 10mm outta the belly pan to clear the spart plug. Well remembered that man!
_________________
If I have to take the carbs off once more...