Still struggling with running problems at high rev, HELP!

[CountryBoy]

Does FT stand for Front Top or Front Timed?, its a really stupid question but when timing the front cyclinder with all the relevant marks in the write places should the piston be at the top of the stroke or the bottom, i think its top but just wanted to check, sometimes the obvious is staring you in the face!.

[John W]

have u set the valve clearances?

Cheers John W

[sirch345]

Sirch345 - to set up the front cyclinder timing i did the follwing :
1. Turn the engine until the FT mark lines up with the static timing mark through the hole in the lower side casing (alternator casing).
2. Install the exhaust cam first keeping the tension on the chain as it comes up from below, position the FE in line with the top of the casing.
3. Install the intake cam and position the FI in line with the top of the casing.
4. At this point all the marks line up perfectly including the (-)'s in the middle.
5. Release the CCT, there is then slight movement in the cams ie the chain pulls them round a touch and this is when you notice the middle marks (-) move apart.

Obviously i've left out all the in between bits like remove covers etc but i'm sure you can fill in the gaps in your head.

CountryBoy so far so good

Still working on the front cylinder:-

1. Are the FI and FE marks on the cam sprockets facing away from each other and NOT facing to-wards each other

2.It sounds like you have got it right, but I'm going to ask anyway, I presume you have fitted the camshafts back into their rightful places, they are marked (inlet camshaft = FR IN and the exhaust camshaft = FR EX) the inlet camshaft should be nearest to the carbs and the exhaust camshaft nearest the exhaust header pipe

Chris.

[CountryBoy]

1. Yes the FE and FI are facing away from each other ie on the outside edges not the inside.

2. Yes the correct cams are in the correct places.

[CountryBoy]

John W - Yes i checked the clearances, they are within the tollerances listed in the manual.

[sirch345]

1. Yes the FE and FI are facing away from each other ie on the outside edges not the inside.

2. Yes the correct cams are in the correct places.

CountryBoy, I'm pleased too hear that

1. When the CCT failed how did you go about finding the correct timing of the crankshaft for the front cylinder considering the cam chain had jumped the teeth of the cam sprockets

2. Have you checked the valve clearances and the timing on the rear cylinder

Does FT stand for Front Top or Front Timed?, its a really stupid question but when timing the front cylinder with all the relevant marks in the write places should the piston be at the top of the stroke or the bottom, i think its top but just wanted to check, sometimes the obvious is staring you in the face!.

I would have thought that FT stands for Front Timing (timing mark for the front cylinder) and RT Rear Timing.
You're right, the piston is at the top of it's stroke TDC (top dead center) when the crankshaft timing marks are lined up (FT or RT) but it has to be on the compression stroke before removing CCT's


Chris.

[VTRmart]

Countryboy,

Ok, here are a few more thoughts on the problem

After the front CCT went, I reset the front timing, checked the rear timing (although it was fine) and fitted new front and rear CCTs.... and as you know i got a misfire at 6k

Second strip down revealed valves hadn't touched pistons, but I lapped them in anyway, since I had the head off.

The only thing that I really noticed during the second rebuild was the choke cables.... I disconnected the carbs during the strip down, and after rebuilding it the choke pulls itself in as soon as I let go of it. It doesn't cause me any grief as it always starts with no choke anyway.... but it didn't used to be like that, so I figure it's worth mentioning.
I connected the fuel tank drain hose this time (I missed this at the first rebuild), this shouldn't have any effect, but.... aagin I'll mention everything I did to cure mine.

At the minute I can only suggest;
1. Make sure you check and set the front AND rear timing with the CCT in place (so the chain is tensioned) and make sure you line up the l mark in front of the FT mark on the timing wheel (I think it's been mentioned before, but the Honda manual makes it look like you set the timing midway between the F and T, which is wrong)
2. Rebuild it all slowly and carefully, make sure no pipes are kinked
3. Make sure the carbs, airbox, filter are all seated correctly and that the o-rings are on the carbs

Can't think of anything else right know, but I hope you have some luck soon mate!

[CountryBoy]

Sirch345 - Sorry but i don't understand your first question, i set the timing as i described before, not sure what your asking?
And yes i have checked the rear cylinder and its spot on for timing and clearances.

VTRmart - Thanks for the suggestions, but i'm not sure how you can adjust the timing if the the tensioner is on the chain, surely this stops you adjusting anything?

[sirch345]

Sirch345 - Sorry but i don't understand your first question, i set the timing as i described before, not sure what your asking?

OK I'll try to put it another way, but I don't really think this will be your problem but I thought worth a mention

If you align the relevant marks for the rear cylinder as you do for removing the CCT (RI and RE marks on the cam sprockets and the RT - mark) then turn the engine over using a socket on the nut on the end of the crankshaft (through the alternator casing) turning it ANTI-CLOCKWISE one and a quarter turns (450 degrees ) until the FT - mark is now aligned, at this point the front FI and FE marks on the cam sprockets should be aligned with the top of the cylinder-head, just as you would for removing the front CCT

Don't forget on the rear cylinder the RI and RE marks will be facing away from each other (cam lobes facing to-wards each other)

The front cylinder the FI and FE marks will be facing away from each other (the cam lobes will be facing away from each other)

Note
When carrying out any work to the valve timing (including CCT replacement) always turn the engine over a few times ANTI-CLOCKWISE by hand before pressing the starter button, just to make sure all the valves are clear of the pistons first

[CountryBoy]

Sirch345 - Ok mate, i follow now, if i do this and the after turning 450 degrees the front timing marks don't line what has caused this.
I haven't touched the rear cyclinder and no damaged occurred there only in the front , the only thing i've done on the rear is checked the clearances, what is the relevance of setting the rear to timed and then turning 450 , so far i have only timed it using the FT and setting up the front, am i missing a crucial part of the procedure?.

[sirch345]

Sirch345 - Ok mate, i follow now, if i do this and the after turning 450 degrees the front timing marks don't line what has caused this.
I haven't touched the rear cyclinder and no damaged occurred there only in the front , the only thing i've done on the rear is checked the clearances, what is the relevance of setting the rear to timed and then turning 450 , so far i have only timed it using the FT and setting up the front, am i missing a crucial part of the procedure?.

As I said previously I don't really think this will be out, but what I was thinking was if the crankshaft kept on turning after the CCT had let go the cam chain had jumped off the cam sprockets may be you have set the front cam spockets on the wrong rotation of the crankshaft

After going over some of your earlier posts in this topic it would appear unlikely that, that happened considering you said the engine runs fine up to 6,000rpm.

Why don't you get the bike all back together and do as I suggested before, get it either dyno'd or connected up to a diagnostic machine It's not as if you've not tried to fix the problem is it You really need to speak with someone like Roger at Revolution Racing about these ideas because I don't know, but I would have thought a run on a dyno would be your best bet considering the misfire only happens under load and above 6,000 revs hopefully then the dyno's computer will be able to pin point the cause

Let us know what you decide

Chris.

[VTRmart]

VTRmart - Thanks for the suggestions, but i'm not sure how you can adjust the timing if the the tensioner is on the chain, surely this stops you adjusting anything?

Sorry, I meant to say set up the timing with the CCT out, but CHECK the timing again after you fit the CCT and the chain gets tensioned.

[CountryBoy]

Thanks for all the suggestions guys, i am going to follow Sirch's instructions at the weekend and see how it goes, i'll let you know.

Thanks again.

[sirch345]

Thanks for all the suggestions guys, i am going to follow Sirch's instructions at the weekend and see how it goes, i'll let you know.

Thanks again.

As I said you must find out from someone who knows about my suggestion first, as it's only an idea of mine but hopefully one that will sort the bike out

Here's Roger's site with contact number if you want to ring him, he won't mind advising you:-

http://www.revolutionuk.co.uk/

[CountryBoy]

I Can't believe it!!!!!, after all this time i've finaly fixed it!!!!!!!, followed Sirch's instructions at the weekend and 'hey presto', it turns out that the bike shop that originally fixed the bike after a CCT failure nearly a year ago had set the timing up 180 degrees out!, after i got the bike back from the shop i'd put it straight into storage and only tested it up and down the road at low speed and it had seemed ok, it was only after about 8 months when i took it back out again that the problem appeared the first time i gave it a hand full.

The stupid part is i assumed (first mistake) that a qualified mechanic in a bike shop would have done a proper job on the original repair and at least got the timing right, because of this assumption i never checked the timing right through i only put the engine to FT and then checked the marks on the cams, checking it right through by setting up the rear first and then checkinig the cam markings showed the FE and FI on the inside instead of the outside, turn the cams through 180 and problem solved, took it for a ride Friday night and we're back to normal.

Just wanted to say thankyou to all the people who helped along the way with suggestions and guidance, and a big thankyou to Sirch, mate your a star!!.