View Full Version : 36 hp 250 with a dodgy tune


tubarney
September 3rd, 2013, 08:32 PM
Thought I would post a thread for anyone who's wondering how things are going.

They say a picture is worth a thousands words. Need I say anymore. Yes catastrophe was avoided. Damage was 80 bucks.... I had spare valves.

http://i1358.photobucket.com/albums/q775/tubarney/20130730_155829_zps459bf62e.jpg (http://s1358.photobucket.com/user/tubarney/media/20130730_155829_zps459bf62e.jpg.html)

I have CR carbs and aftermarket camshafts going in next week for another dyno run in 2 weeks. I will post results of the run.

Carbs are not tuned because CR's are going on next week. The stock carbs are sh**.

This dyno run is with Stock carbs, stock cams and stock ignition timing. Compression has been fixed. 190 p.s.i on both cylinders.

http://i1358.photobucket.com/albums/q775/tubarney/IMG_zpsc799bf3d.jpg (http://s1358.photobucket.com/user/tubarney/media/IMG_zpsc799bf3d.jpg.html)

lgk
September 3rd, 2013, 08:57 PM
Glad you got working.

Will you break 40 with a tune?

quarterliter
September 3rd, 2013, 08:58 PM
I'm hoping you will hit 40!

ninja250r81
September 4th, 2013, 12:48 AM
curve looks nice and strong:thumbup:

Racer x
September 4th, 2013, 03:41 AM
That's good power. You will love the CR carbs.

How did the valve bend?

mgentz
September 4th, 2013, 03:47 AM
Hey...

Do you have a root cause? I am tearing mine apart this winter to diagnose the compression issue. I will be checking the valves as well.

I expect that I can make 40 hp when I know everything is tight. I just wanted to ride after 8 months of work.

mgentz
September 5th, 2013, 04:05 AM
If you do get the CR carbs, please let me know if it helps the power/tune. Mine idles like ^%#*% and the high RPM/low throttle movements are horrible. For those who would like to solve this....I have tried and the tuner has spent SOME time on it as well with the same results.

Besides, I posted a thread about the "ultimate" tune, for that I need to get them right? :) I won't get them till over the winter if I do, but Racer x I will have lots of questions ;)

Otherwise, tubarney it may be a good idea to merge this with the thread you and I were oringinally working with. Less clutter and resolution, or at least some data until the next update.

tubarney
September 6th, 2013, 07:54 AM
Glad you got working.

Will you break 40 with a tune?

Hope so.

The carbs, beet cams and brt are going on next week. I will have carbs in a couple of days now. Ordered them 30th August and there in stock at Keihin Japan.

That's good power. You will love the CR carbs.

How did the valve bend?

I forgot to double check timing after tensioner install:eek:, I cranked it around with a wrench prior to starting, pistons and valves hit. I fixed the timing and started it. It idled for 30 secs fine then starting ticking. I killed it and pulled it apart to find a valve seal where the shim should be, a chipped shim on top of the spring, 4 bent intake valves, 1 valve being held in by 1 collet!!!!!!!!!!. I was extremely lucky. A few more secs and it was game over.

Vintage Smoke
September 7th, 2013, 11:49 AM
What was the outcome of your piston and cylinder issue?