3TJ Engine Transplant

[oollit]

Had another go at the 3TJ today.

I checked the coils and they seem fine so i put the tank on without the airbox and went for a spin.
Amazingly it moved but it is rough and won't rev past 6000 revs and it was blowing back through the carbs.

I had to set the valve timing and i am wondering if i am a teeth out on the inlet cam and the inlet valves are opening too soon alowing combustion gases to exit through the carb.

I lined the T mark on the flywheel with the join in the crank cases and the cams with the centre punched marks in the end of the cams with the marks on the end of the cam cap rail, when i count the cam chain links between the dots on the cam sprockets i get 10.5 links. Does this sound about right or am a teeth out somewhere?

[Marb]

Did you remove the cams? In that case did you mount the exuast cam first? So you align the T-mark with the cases, then install the exuast cam, then install the intake cam so that the holes line up with the dots on the cam cap rail. Then stick a screwdriver in the chaintensioner hole and push hard. Now get someone to crank the engine round twice, you should feel the screwdriver move in and out a coupla times. Once you've gone round twice, then check the tension of the chain between the cams. It shouldnt have more than a couple of mm's of slack. Then mount the chaintensioner and the top chainguard. Now turn the engine round twice again and it should all line up perfectly with no slack.

[oollit]

When i set up the timing, i did pretty much exactly what you describe Marb.

I have advanced and retarded the inlet cam 1 tooth and the bike would not run so the cam timing must have been ok.

Looks like i will have to set the timing back to what it originally was today and start looking again tomorrow.

[Marb]

Did you check your valve clearences? My inlet-valve clearences were pretty messed up resulting that i couldnt get above 9000rpm with my 400.

Another option is that the coils are messed up. Does the bike run worse when it is warm? Let the bike run for about 10mins and feel if the coils get warm. They should get a little warm, but you should be able to hold on to them. If they get so hot that you can't hold on to them then you've found you're problem.

Another option could be your VR. Check the charge current at 5000rpm. It should be around the 14V. If it is lower then your VR has died or you have a faulty connection somewhere.

If the fuelpump has died then your rpm-meter should be displaying 3000 extra revs. Which means that it should say that you are ideling at about 4500 om the rpm-meter when acctually you are at 1500. This is a fault-diagnose system build in by Yamaha.

[oollit]

I put the timing back to what it was, but the battery is flat and my brother has taken the jump leads to his work today so i am screwed.

I have to face facts that i am not going to make the bike rally tomorrow and have decided to go out to sea for a weeks fishing on a trawler at 5pm tonight, as a local boat is shorthanded and they have just phoned me up to see if i am available.

I need a break from the 3TJ as i have been working on it day and night now for over a week to try and get it going and i am sick of the sight of it now.

[Dobbie]

Hello Oollit, This is a long shot but worth a go. I take it you have had the generator casing off. I had my casing off once to paint it and when I put it back on, the magnets snatched it slightly and it had hit the magnetic pickup and bent the bracket a tiny bit. God did that cause me some grief, It wouldn't rev properly, It would start then pack up, then pop back through carbs or backfire, then only start with easy start. I cleaned the carbs, checked the coils everything and in the end noticed it was the bracket, nudged it straight and it's been perfect since, worth a look.

[oollit]

It will definately be worth looking at as that is exactly what my bike is doing. I have had the genny cover off about 20+ times now so i could easily have dislodged the pick up mounting bracket and altered the ignition timing.

That has got me thinking. The engine i have fitted to the bike is an RRSP engine, i wonder if the SP flywheel is different from the RR one as i am running the RR cdi with the SP flywheel so if the flywheels are different the the cdi could be triggering the coils at the wrong time? might be worth fitting my RR flywheel too.

I am leaving to go back to sea for 2 weeks at lunchtime tomorrow so i won't have time to do anything before i go but that will be a few things for me to try when i get back home.

[Dobbie]

I think the flywheel would probably be the same but not sure, I know the rr is the same as an fzr600, so I wouldn't imagine the sp would be different. Is the engine you have put in known to be a good one?

[Motorcycle Solutions]

The engine that he has got was working perfect for i had transplanted into my sp frame after blowing up my head gaskets and used as a standard road engine and it gained me a beutiful 24th place out of 32 riders at brands hatch in march.

OOllit check the valve clearences and get hold of a 4dx box this should work perfect with the engine my good frien for that is the model sp it came from.. 3tj cdi mapping is different but fly wheel is the same.

For i put my rr cdi on my sp and my sp would not rev past 4000 revs and after change of cdi it worked fine and also change relay box.

Good Luck

P.s How was the fishing trip.

:) :) :) :)

[nry]

For i put my rr cdi on my sp and my sp would not rev past 4000 revs and after change of cdi it worked fine and also change relay box.

Thats weird ! I've got 2 RR's and and SP and then theres the boxes I've bought off ebay to modify and I swap them all over the place, I couldn't tell you which one was on the SP at the moment, but its always run no problems - very sweet infact.
Could I have just been lucky ?
I might test that theory out with the ones I've on the shelf, they cant all be SP cdis.. I'll get back to you.
Neil.