Tz350 new engine idea. Will it go bang?

**richban** · 28th January 2010, 21:10

Bring your favorite hankie.

**SS90** · 28th January 2010, 21:56

Originally Posted by woodyracer

put on a cbr125r fuel injection system!........then you'll get some more ponies

How?

from what others have posted, 15hp is your lot, and that is with a power commander

Like I have said Woodyracer, 15 horsepower comes from 20 year old 125cc singles with GN250 carbs, and some guys with FXR150's are getting substantually more than that.

Sorry mate, the addition of fuel injection does not instantly bring power.

Cripes, 10 years ago we pulled an injection system off a Triumph T595, and fitted it with a set of Mikuni FCR flatslides, the damned thing instantly made 10 horsepower more, and revved out so much faster that we had to convert it to under bucket shims (from the factory bucket over shim set up) just to stop it spitting shims out.

No mate, fuel injection does not always mean more power.

**F5 Dave** · 29th January 2010, 09:02

A fair call. FI has been brought in for emissions control & can be made quite cheaply. Top level GP 2 strokes all ran carbs (with a few exceptions like Itohs NSR). 750cc superbikes ran with carbs while they could as std on roadbikes. OK things have moved on & FI has caught up, but it goes to show how close it was, but hardly expect a production FI system to be a step up from a decent carb.

Of course you could run a GSXR600 with 3 cyl blanked off & that would give you a 150 with FI all set up for that cylinder..

Has this thread gone slightly off course yet?

**Buckets4Me** · 29th January 2010, 12:14

Originally Posted by F5 Dave

Has this thread gone slightly off course yet?

not quite yet

Now I'm thinking of buying a fyran 580 tinny to go fishing in
is this the best boat for me or should I go all out and get a Rayglass 2150 with the twin 2.6l supercharged outboards ???

**saxet** · 29th January 2010, 12:42

Originally Posted by Buckets4Me

not quite yet

Now I'm thinking of buying a fyran 580 tinny to go fishing in
is this the best boat for me or should I go all out and get a Rayglass 2150 with the twin 2.6l supercharged outboards ???

I'd go for a second hand Earth Race boat.

**Buckets4Me** · 29th January 2010, 13:54

Originally Posted by saxet

I'd go for a second hand Earth Race boat.

with or without the Jap core sample ??

**F5 Dave** · 29th January 2010, 16:46

With Whaleskin hubcaps. Hmm maybe boats aren't my thing. . .

**TZ350** · 29th January 2010, 17:22

Ok we have had our very first backfire...........

I was just pushing of to start the bike, throttle closed and as it turned over, it backfired, very loud "POP" but no damage, the blow of plate did its job. Surprisingly it lifted right up, about 20mm.

Those that voted it would blow up........."Wrong".......

**Pumba** · 29th January 2010, 17:52

Originally Posted by Buckets4Me

not quite yet

Now I'm thinking of buying a fyran 580 tinny to go fishing in
is this the best boat for me or should I go all out and get a Rayglass 2150 with the twin 2.6l supercharged outboards ???

The 2.6L supercharged outboards are ditry four stokes. The evinrude E-tec 225 or 250 would be the engine pick of the moment (2 year racing warenty as well), personally I love the Mercuary 300X (I have an afinity with mercs) but along with the Yamaha 300, and 225 they seem to have developed a nasty habit of blowing up latley (bloody two strokes)

Now wack any those bastards on the back of a fishing rig and it wont matter if there are fish or not.

**Yow Ling** · 29th January 2010, 17:53

we not worried yet, testing isnt complete. Have you thought of the merits of on board fire extinguisher.

Did it used to spit back when it wasnt a plenum thingy or is this a new thing. Do you think this is a disk valve thing, its hard to imagine it happening on a reed valve engine.

**TZ350** · 29th January 2010, 19:05

Originally Posted by Yow Ling

we not worried yet, testing isnt complete.

"not worried yet", you should be seriously worried I would think….

but as you say. "testing isn’t complete"..........whatever problems there will be getting it all running properly, we now know a spectacular plenum blow up is not going to be one of them.

It starts easy, idles, runs better with some re-jetting and does not blow up after a backfire, so getting there.

**TZ350** · 29th January 2010, 19:11

Originally Posted by Yow Ling

Do you think this is a disk valve thing, its hard to imagine it happening on a reed valve engine.

Full system load of air/fuel mixture, wasted spark ignition, backfire could happen to any motor.....

but backfire through the carb on one with reed valves, not sure??? intuitively wouldn't think so.....butttt......

**Henk** · 29th January 2010, 21:07

Originally Posted by TZ350

backfire through the carb on one with reed valves, not sure??? intuitively wouldn't think so.....butttt......

Have seen this on an RM250 with a dodgy earth on the coil. Would backfire through the carb and leave witness marks on the inside of the air filter.

**RMS eng** · 30th January 2010, 08:18

70s plenum tube for KX125 ,made by sunk works, so you could run a bigger carb 26mm-32mm.

**TZ350** · 30th January 2010, 13:43

Yes...good idea, now that I have seen the picture I think I remember it from a Kawasaki trail bike manual. At the time I thought it was for changing the tuned length. But I can see how this could be made as a plenum chamber like mine, but with less volume. Thanks for reminding me of it, it could be very usefull if my current plenum proves to be too big.