H100 losing power

[Spearson]

Got the H100 moted last week and have been riding it about scince i managed to get tax on saturday . But i have noticed an annoying fault, it loses power. This generally tends to happen while holding a constant speed in either 4th or 5th gear, you'll be going along and its very noticable that its losing power to a point where you will have to change down, then change down again, sometimes you will even have to come to a stop! This problems really got me stumped, because the bike pulls nicely up through 1st, 2nd and 3rd with no problem, its also very inconsistant, most of the time it will lose power but very occasionally its fine. I have checked the air filter its clean and oiled, the carb has been thoroughly cleaned and properly reassembled and the whole exhaust ststem has been de-coked. Its starting to bug me now because every journy i do on the bike takes twice as long because i either have to keep slowing down or stop. The one thing i think it could be is the coil. My bike the the H100SII, and to quote the haynes manual the resistance of the primary coil is 0.16- 0.20 ohms, and the secondary coil 3.7- 4.5k ohms. But currently i have a coil fitted off the earlier H100A which has a resistance on the primary coil of 0.2- 0.3 ohms, and a resistance round the secondary coil of 3.4- 4.2k ohms. Would this be causing the problem? Is there anyone more electronically/ mechanically minded out there who could help me please.
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'05 Yamaha Jog R (in fancy plum) sold to a chav, '91 Yamaha SR125 (stripped and rebuilt) sold to an Australian, '88 Honda H100S (crap) bought by 3 retards

[stinkwheel]

I'd suggest that if it was an electrical problem, it'd be happening in every gear. The mechanism for making the spark is the same at 10k in first as it is at 10k in fourth.

From the engines point of view. The only real difference is the load on it. The amount of fuel, air and the occurrance of the spark is identical in each gear.

My concern would be that it might be trying to nip up on you. Did you check the oil pump settings and make sure it was working? Did you look at the bore or have to replace any bits of the top end when you rebuilt it?

I'd also suggest doing some plug chops at full revs to check the mixture is right.
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“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Spearson]

I have checked the oil pump and it is set correctly, both marks on it allign perfectly, i also made sure i alligned the correct marks. As for the engine its currently an unknown, it was bought off ebay because the bikes original engine was, well broken, someone had tried to run it without oil, obviously ruining the top end and at the same time it took out the bottom end so we deemed it an uneconomical repair and replaced it. The engine in there now 'sounds' fine, little bit off top end noise but nothing excessive. To be honest i havn't had this engine apart to do a top end rebuild. I know this isnt the best thing but i also dont know when the last rebuild was or even how many miles this engine has on it. But the fact it pulls really well up untill 4/5th gear suggests there can't be much wrong with the engine (correct me if i'm wrong!). I don't know if it could be fauly reed valves, i havnt checked those.
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'05 Yamaha Jog R (in fancy plum) sold to a chav, '91 Yamaha SR125 (stripped and rebuilt) sold to an Australian, '88 Honda H100S (crap) bought by 3 retards

[stinkwheel]

Did you prime the oil pump and check it is actually working?

Is it blowing round the base or head gasket?

Again, plug chops should tell you a lot about what is happening. Especially if you do one at the point this power drop occurrs.

It isn't something as simple as you coming into a head wind or an incline though? Even a slight hill can see you down to 45mph on an H100.

If it was an electrical problem, you would almost certainly feel the engine 'missing' rather than a simple loss of power.

Reed valves are easily checked.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[Spearson]

Lol yes, a head wind does slow it down but it isnt that. I have checked the plug several times. I rode it once with the oil set too high not massivly so but slightly and it was holding back so i adjusted the oil properly hoping it would solve the problem. Checked the plug while the oil was set too high and obviously it was all oily, so i wiped it clean. I then checked the plug again after a 10-15 mile ride after the oil was set and it looks perfect. The electrode and tip are light brown in colour with no abnormal deposits on it, during the ride the bike was still playing up. It is getting oil because the level of 2 stroke in the oil reseviour has gone down, and theres blue smoke coming out the exhaust.
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'05 Yamaha Jog R (in fancy plum) sold to a chav, '91 Yamaha SR125 (stripped and rebuilt) sold to an Australian, '88 Honda H100S (crap) bought by 3 retards

[foldy86]

Simple remedy, buy mine for its good engine!!! and then build another one using the rest of the bits!!!!!

[ms51ves3]

[foldy86]

Not too sure whats up with the kickstart, cant be musch as theres nothing to them!